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  • 1975-1979  (4,069)
  • 1870-1879  (5,019)
  • Inorganic Chemistry  (8,782)
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  • 101
    Electronic Resource
    Electronic Resource
    Stoffwechselprodukte von Mikroorganismen, 172. Isolierung des Antibioticums semi-Vioxanthin aus Penicillium citreo-viride und Synthese des Xanthomegnins (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 957-978 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Metabolic Products of Microorganism, 172. Isolation of the Antibiotic semi-Vioxanthin from Penicillium citreo-viride and Synthesis of XanthomegninBesides xanthomegnin (16 b), 3,4-dehydroxanthomegnin (29a), viomellein (23) and vioxanthin (3) from Penicillium citreo-viride under different culture conditions semi-vioxanthin (7) was isolated. Structure 7 has been established by its spectra and the fact that oxidation with Fremy's salt gives 3,4,6,9-tetrahydro-10-hydroxy-7-methoxy-3-methyl-1,6,9-trioxo-1H-naphtho[2,3-c]pyran (9a = semi-xanthomegnin). -9c, prepared by demethylation of 9a, was dimerized by potassium peroxydisulfate/sodium hydroxide and methylated, giving 16b. Synthetic 16b and authentic xanthomegnin were identical, which verifies the structure revised by Höfle and Röser9) and shows, that the dyes of the xanthomegnin series are biogenetically homogenous. - The metabolic products of the strain inhibit the growth of bacteria. 16b and 26 furthermore have an effect against insects.
    Notes: Neben Xanthomegnin (16b), 3,4-Dehydroxanthomegnin (29 a), Viomellein (23) und Vioxanthin (3) wurde aus Penicillium citreo-viride unter veränderten Kulturbedingungen semi-Vioxanthin (7) isoliert. Konstitution 7 folgt aus den Spektren und dem Befund, daß mit Fremy-Salz 3,4,6,9-Tetrahydro-10-hydroxy-7-methoxy-3-methyl-1,6,9-trioxo-1H-naphtho[2.3-c]pyran (9a = semi-Xanthomegnin) entsteht. - Das durch Entmethylierung von 9a zugängliche 9c ließ sich mit Kaliumpersulfat/Natriumhydroxid zu 16a dimerisieren, das zu 16b methyliert wurde. Synthetisches 16b war mit nativem Xanthomegnin identisch, was die von Höfle und Röser9) revidierte Konstitution bestätigt und beweist, daß die Farbstoffe der Xanthomegnin-Reihe biogenetisch einheitlich sind. - Die Stoffwechselprodukte des Stammes hemmen das Wachstum von Bakterien, 16b und 23 wirken ferner gegen Insekten.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120319
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  • 102
    Electronic Resource
    Electronic Resource
    Mikrobiologische Umwandlung von Steroiden, XVI. Synthese von 11β, 21-Dihydroxy-6, 16α-dimethyl-1,4,6,-pregnatrien-3,20-dion und dessen 11-Ketoverbindung (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 979-989 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Microbial Transformations of Steroids XVI. Synthesis of 11β,21-Dihydroxy-6, 16α-dimethyl-1,4,6-pregnatriene-3,20-dione and of its 11-Keto Compound21-Acetoxy-5α,6α-epoxy-3β-hydroxy-6β16α-dimethyl-20-pregnanone (3a), prepared from 3β-hydroxy-6, 16α-dimethyl-5-pregnen-20-one (1) by epoxidation and chemical introduction of the 21-acetoxy group, was oxidized to 6α,21-dihydroxy-6β,16α-dimethyl-4-pregnene-3,20-dione (4) by Flavobacterium dehydrogenans and dehydrated to the 3-keto-4,6-diene 5. The 11β-hydroxy group was introduced by Curvularia lunata to give 6, and the 11α-hydroxy group by Aspergillus ochraceus to yield 8. Both compounds were dehydrogenated with Bacillus lentus to from 7 and 9. The 11α-hydroxy compound 9 was selectively acetylated to 10, which was oxidize to 11. This on saponification yielded 12.
    Notes: 21-Acetoxy-5α,6α-epoxy-3β-hydroxy-6β,16α-dimethyl-20-pregnanon (3a), dargestellt aus 3β-Hydroxy-6, 16α-dimethyl-5-pregnen-20-on (1) durch Epoxidierung und 21-Acetoxylierung, wurde mit Flavobacterium dehydrogenans zu 6α,21-Dihydroxy-6β, 16α, -dimethyl-4-pregnen-3,20-dion (4) oxidiert und zu 21-Hydroxy-6, 16α-dimethyl-4,6-pregnadien-3,20-dion (5) dehydratisiert. Mit Curvularia lunata wurde die 11β-Hydroxygruppe eingeführt zu 6, während Aspergillus ochraceus die entsprechende 11α-Hydroxyverbindung 8 ergab. Beide Verbindungen wurden mit Bacillus lentus zu 7 bzw. 9 dehydriert. Die 11α-Hydroxyverbindung 9 wurde nach selektiver Acetylierung der 21-Hydroxygruppe zu 10 zum 11-Keton 11 oxidiert, dessen Verseifung 12 ergab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120320
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  • 103
    Electronic Resource
    Electronic Resource
    Neue Synthesen mit Diazodiketonen, IV. Cyclische S-Oxide (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1012-1022 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: New Syntheses with diazodiketones, VI. Cyclic S-OxidesThe S-oxides 4 of 3,4-dihydro-1,2,3-oxathiazines and 5 of 1,2-oxazetidines are prepared a) by thermolyzing diazodiketones 1 with N-Sulfinylamines 3; b) by condensing the 2-acylacetamides 6 which are readily accessible from 1, with thionyl chloride in the presence of a basic catalyst. From 6, the aminoacrylamides 7 are obtained. These react with thionyl chloride according to the base employed, to afford either the monocyclic 3,6-dihydro-1,2,6-thiadiazine-S-osides 10 or the 4-amino-quinolines 8, presumably via the intermediacy of an imine 9. - The introduction of the SO group into (hetero)cyclic iminocarboxamides, diamines or aminophenols give rise to the S-oxides 13 of condensed thiadieazines, 15a-c of benzothiadiazole, or 15d of benzoxathiazole, respectively.
    Notes: Die 3,4-Dihydro-1,2,3-oxathiazin- 4 und 1,2-Oxazetidin-S-oxide 5 werden a) durch Thermolyse der Diazodiketone 1 mit N-Sulfinylaminen 3 b) durch basenkatalysierte Kondensation der aus 1 leicht zugänglichen 2-Acylacetamide 6 mit Thionylchlorid hergestellt. Aus 6 weden die Aminoacrylamide 7 erhalten. Diese reagieren mit Thionylchlorid je nach der verwendeten Base entweder zu monocyclischen 3,6-Dihydro-1,2,6-thiadiazin-S-oxiden 10 oder über eine Imidoylketenimin Zwischenstufe 9 zu den 4-Aminochinolinen 8. - Der SO-Einbau mittels Thionylchlorid in (hetero)-cyclische Iminocarboxamide, Diamine und Aminophenole führt zu den S-oxiden 13 kondensierter Thiadiazine, 15a-c des Benzothiadiazols bzw. 15d des Benzoxathiazols.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120323
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  • 104
    Electronic Resource
    Electronic Resource
    Untersuchungen zur Modifizierung der Mannobiose und Synthese von Methyl-4-O-β-D-rhamnosyl-α-D-olivosid (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1035-1045 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Studies on the Modification of Mannobiose and Synthesis of Methyl 4-O-β-D-Rhamnosyl-α-D-OlivosideBy acid-catalyzed reaction of α-mannobiose octaacetate (2) with trichloroethanol or phenol the glycosides 6 or 9a, and with hydrogen bromide/acetic acid the glycosyl bromide 3 are obtained. Koenigs-Knorr reaction of 3 with methanol of benzyl alcohol yields the orthester derivatives 7a or 7b, respectively. Mannobial hexaacetate 8 is obtained from 3 an d transformed into 12a by iodomethoxylation. The selective tosylations of 9b or 12b in the 6- and 6′ -positions yields the ditosylates 10 or 13a, which in turn give the corresponding diiodo compounds 11a or 5a, respectively. By subsequent reduction using nickel chloride/sodium borohydride the syntheses of the glycosides 14 and 17b of 4-O-(β-D-rhamnopyranosyl)-α-D-rhamnopyranose or 4-O-(β-D-rhamnopyranosyl)-α-D-olivopyranose, respectively, are achieved. All new compounds are characterized by peracetates, and their structural assignment is confirmed from their NMR spectra.
    Notes: α-Mannobiose-octaacetat (2) läßt sich sauer katalysiert mit Trichlorethanol oder Phenol zu den Glycosiden 6 bzw. 9a oder mit Bromwasserstoff in Eisessig zum Glycosylbromid 3 umsetzen. Koenigs- Knorr-Reaktion von 3 mit Methanol oder Benzylalkohol ergibt die Orthoester 7a bzw. 7b. Aus 3 wird Mannobial-hexaacetat 8 gewonnen und zu 12a iodmethoxyliert. 9b bzw. 12b lassen sich selektiv in 6- und 6′- Position zu 10 bzw. 13a tosylieren und anschließend in die entsprechenden Iodide 11a bzw. 15a überführen. Deren Reduktion mit Nickelchlorid/Natriumboranat in Ethanol erlaubt die Darstellung der Glycoside 14 and 17b von 4-O-(β-D- Rhamnopyranosyl)-α-D-rhamno-pyranose bzw. 4-O-0(β-D-Rhamnopysanosyl)-α-D-olivopyranose. Alle Syntheseprodukte werden durch Peracetate charakterisiert und strukturell an Hand der NMR-Spektren zugeordnet.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120325
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  • 105
    Electronic Resource
    Electronic Resource
    Synthese, Strukturaufklärung und Konformationsuntersuchungen 1→4-verknüpfter Disaccharidglycoside vom 2,3-Anhydro-4-O-(hex-2-enopyranosyl)-α-D-allopyranosid-Typ (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1023-1034 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis, Structure Elucidation, and Conformational Studies of 1→4-Linked Disaccharide Glycosides of the 2,3-Anhydro-4-O-(hex-2-enopyranosyl)-α-D-allopyranoside TypeTriacetyl-D-glucal (1) or tetraacetyl-2-hydroxy-D-glucal (6) and 2,3-anhydro-α-D-allopyranosides 2 or 7, respectively, undergo smooth acid-catalyzed allylic rearrangement reactions to yield the crystalline α-linked disaccharide derivatives 4, 5, and 9 with hex-2-enopyranosyl structure in the non-reducing rings in good yields. By hydrogenation of 4 and 5, 8 is obtained, in which the α-linkage can be demonstrated. X-ray analysis confirms the interglycoside α-linkage in the considerably stretched disaccharide derivative 5. Both the saccharide ring adopt SO5 sofa conformations, in which only C-5 and C-5′ ae observed significantly below the plane of the remaining ring atoms. The NMR data of 5 and 9 suggest also SO5 sofa conformation in solution. On the contrary the β-isomer 10 adopts 5SO sofa conformation which is consistent with the allylic effect.
    Notes: Durch sauer katalysierte Addition der 2,3-Anhydro-α-D-allopyranoside 2 bzw. 7 an Triacetyl-D-glucal (1) bzw. Tetraacetyl-2-hydroxy-D-glucal (6) lassen sich unter Allylumlagerung die α1→4-verknüpften Disaccharide 4, 5 und 9 mit Hex-2-enopyranosyl-Struktur im nicht-reduzierenden Saccharidring milde und in guten Ausbeuten kristallin gewinnen. Durch Hydrierung von 4 und 5 wird 8 erhalten, bei dem die interglycosidische α-Verknüpfung nachgewiesen wird. Die Röntgenstrukturanalyse von 5 bestätigt die α-Verknüpfung in dem erheblich gestreckten Disaccharidderivat. Beide Saccharidringe weisen eine SO5-Sofakonformation auf, bei der nur die Atome C-5 und C-5′ wesentlich aus der Ebene der übrigen Ringatome nach unten herausstehen. Konformationsbetrachtungen legen auch in Lösung für 5 und 9 das Vorliegen einer SO5-Sofakonformation nahe. Das interglycosidische β-Isomere 10 weist dagegen eine 5SO-Sofakonformation auf, was auf den Allyleffekt zurückgeführt werden kann.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120324
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  • 106
    Electronic Resource
    Electronic Resource
    Untersuchungen zur Modifizierung der Laminaribiose und Synthese von Methyl-3-O-β-D-chinovosyl-α-D-olivosid (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1046-1056 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Studies on the Modification of Laminaribiose and Synthesis of Methyl 3-O-β-D-Quinovosyl-α-D-olivosideLaminaribiose (2) and the peracetates 3a and b are obtained by acetolysis of laminaran or pachyman, respectively. Via formation of the bromide 5, the β-methyl (6) and β-benzyl glycosides (7a and b) as well as the glycals 9a and b are obtained in crystalline form. Iodoalkoxylations with benzyl alcohol yield the epimeric benzyl glycosides 10a and b, whereas with methanol 11a is obtained exclusively. 11b is transformed into the dibenzylidene compounds 12a-c. the reaction of which with N-bromosuccinimide leads to the formation of the 2,6,6′- trihalo derivatives 13a and b. By subsequent reduction the title compound 14b is obtained and characterized as its peracetate.
    Notes: Ausgehend von Laminaribiose (2) und ihren Peracetaten 3a und b, die durch Acetolyse von Laminaran bzw. Pachyman zugänglich sind, lassen sich über das Bromid 5 die β-Methyl- (6) und β-Benzylglycoside (7a und b) sowie die Glycale 9a und b kristallin gewinnen. Iodalkoxylierung mit Benzylalkohol gibt die epimeren Benzylglycoside 10a und b, während mit Methanol einheitlich 11a isoliert wird. Aus 11b werden die Dibenzylidenverbindungen 12a-c dargestellt, deren Öffnung mit N-Bromsuccinimid zu den 2,6,6′-Trihalogenderivaten 13a und b führt. Durch Reduktion wird daraus die Titelverbindung 14b gewonnen und als Peracetat charakterisiert.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120326
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  • 107
    Electronic Resource
    Electronic Resource
    Tertiäres Phosphan/Hexachlorethan als Kondensationsreagenz für die Peptidsynthese (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1057-1063 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Tertiary Phosphane/Hexachloroethane as Condensing Agent in Peptide SynthesisThe action of tertiary phosphane/hexachloroethane on N-protected amino acids and amino acid esters is found applicable for peptide synthesis. No difficulties are found when the side chains of serine, threonine, tyrosine, asparagine and glutamine are present. By addition of 1-hydroxybenzotriazole racemisation is prohibited as indicated by the test of Anderson.
    Notes: Mit dem Dehydratisierungsreagenz tertiäres Phosphan/Hexachlorethan lassen sich N-geschützte Aminosäuren und Aminosäureester in hohen Ausbeuten zu Peptiden kondensieren. Funktionelle Gruppen in den Seitenketten von Serin, Threonin, Tyrosin, Asparagin und Glutamin werden nicht angegriffen Unter Zusatz von 1-Hydroxybenzotriazol verläuft der Anderson-Test racemisierungsfrei.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120327
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  • 108
    Electronic Resource
    Electronic Resource
    Synthetische Arbeiten in der Reihe der aromatischen Erythrina-Alkaloide, XXIII. 1,7-Cyclo-cis-erythrinane (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1110-1125 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses of Aromatic Erythrina Alkaloids, XXIII. 1,7-Cyclo-cis-erythrinanesThe 1,7-cyclo-cis-erythrinane derivative 17 is formed by heating the bromo compound 13 with potassium hydroxide in diethylene glycol to 180°C. Hydrolysis of 17 yields the ketone 18 which, by reactions of the carbonyl group, is transformed into the cyclic compounds 19 - 21 and 27 - 33. The cyclopropane ring is easily cleaved by reduction to give the unsaturated lactam 10 or the saturated lactam 1. The 1,7-cyclo-cis-erythrinane structures 37 and 38 can be synthesized by way of the cyclic olefin 35.
    Notes: Durch Erhitzen der Bromverbindung 13 mit Kaliumhydroxid in Diethylenglycol auf 180°C entsteht das 1,7-Cyclo-cis-erythrinan-Derivat 17. Nach Hydrolyse zum Keton 18 erhält man durch Umwandlung der Ketogruppe die Cycloverbindungen 19 - 21 und 27 - 33. Reduzierende Bedingungen spalten den Cyclopropanring sehr leicht auf unter Bildung des Olefinlactams 10 oder des gesättigten Lactams 1. Über das Cycloolefin 35 gelingt die Darstellung von 37 und der zugehörigen Base 38 mit dem Grundgerüst der 1,7-Cyclo-cis-erythrinane.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120407
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  • 109
    Electronic Resource
    Electronic Resource
    Synthetische Arbeiten in der Reihe der aromatischen Erythrina Alkaloide, XXIV. Über die Bromierungsprodukte von 15,16-Dimethoxy-cis-erythrinan-2,8-dion (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1126-1139 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses of Aromatic Erythrina Alkaloids, XXIV. On the Products of Bromination of 15,16-Dimethoxy-cis-erythrinane-2,8-dioneBromination of 1 as well as hydrolysis of 5 (with inversion at C-l) yields the bromoketolactam 2. This can be converted back to 5, again with inversion. On reduction of 2 with sodium tetrahydridoborate, the bromohydrines 11-13 and the epoxide 17 are obtained. The epimeric bromoketolactam 6 cannot be isolated, but is an intermediate in the formation of 12 and 13. 2 reacts with potassium hydroxide in methanol or ethylene glycol to give the hydroxyacetals 18 and 19, respectively. From 1 the dibromoketones 24 and 25 were prepared which exhibit unusual spectral properties.
    Notes: Das Bromketolactam 2 wird aus 1 durch Bromierung oder aus 5 durch Hydrolyse unter Umkehrung der Konfiguration an C-l erhalten. Auch die entgegengesetzte Reaktion von 2 nach 5 verläuft unter Umkehr. Mit Natriumboranat liefert 2 die Bromhydrine 11, 12, 13 und das Epoxid 17. Bei der Bildung von 12 und 13 ist wieder das selbst nicht faßbare epimere Bromketolactam 6 Zwischenprodukt. Die Umsetzung von 2 mit Kaliumhydroxid in Methanol oder Ethylenglycol führt zu den Hydroxyacetalen 18 oder 19. Die aus 1 dargestellten Dibromketone 24 und 25 haben auffallende spektroskopische Eigenschaften.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120408
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  • 110
    Electronic Resource
    Electronic Resource
    Methylschwefelpentafluorid und einige seiner Derivate (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1140-1146 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Methylsulfurpentafluoride and Some of its DerivativesMethylsulfurpentafluoride (5) was systematically synthesized, starting with SF5Cl and ketene. It is stable at room temperature against HF elimination. The reaction of SF5Cl and diketene gives compounds of the type SF5—CH2—X, but the title compound is not produced in this way.
    Notes: Methylschwefelpentafluorid (5) wurde systematisch synthetisiert, ausgehend von SF5Cl und Keten. Es ist bei Raumtemperatur stabil gegen HF-Eliminierung. Die Reaktion von SF5Cl und Diketen führt zu einer Vielzahl anderer Verbindungen des Typs SF5—CH2—X, in einfacher Weise jedoch nicht zur Titelverbindung.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19791120409
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  • 111
    Electronic Resource
    Electronic Resource
    Synthesen biologisch wichtiger Kohlenhydrate, 20. N-Acetyl-1,4-di-O-acetyl-β-DL-vancosamin (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3273-3281 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses of Biologically Important Carbohydrates, 20. N-Acetyl-1,4-di-O-acetyl-β-DL-vancosamineClaisen rearrangement of 1-methyl-2-butenyl vinyl ether (3) yields trans-3-methyl-4-hexenal (4), the ethylene acetal 5 of which is aminated with selenium and chloramine T forming a mixture of the 3-methyl-3-tosylamino- (6) and 3-methyl-6-tosylamino derivatives 7. After detosylation of 6 and N-acetylation trans-3-acetylamino-3-methyl-4-hexenal ethylene acetal (9) is cis-hydroxylated to give 10/11. Cleavage of the protecting group at C-1 and peracetylation gives n-acetyl-1,4-di-O-acetyl-β-DL -vancosamine (13). The constitution of 13 is proved by mass spectrometry and the lyxo-configuration is assigned with high probability on the basis of 1 H NMR investigation *).
    Notes: Die Claisen-Umlagerung von (1-methyl-2-butenyl)-vinyl-ether (3)liefert trans-3-Methyl-4-hexenal(4), dessen Ethylenacetal 5 mit Selen und Chloramin-T zu den 3-Methyl-3-tosylamino-(6) und 3-Methl-6-tosylamino-Derivaten 7 aminiert wird. Nach Detosylierung von 6 und N-Acetylierung wird trans-3-Acetylamino-3-methyl-4-hexenal-ethylenacetal (9) zu 10/11 cis-hydroxyliert. Abspaltung der Schutzgruppe an C-1 und Peracetylierung liefert n-Acetyl-1,4-di-O-acetyl-β-DL-vancosamin (13), dessen Konstitution durch MS bewiesen und dessen lyxo-Konfiguration durch 1 H-NMR-Untersuchungen weitgehend gesichert wird *).
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120922
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  • 112
    Electronic Resource
    Electronic Resource
    Monomere Bis[dialkylphosphonium-bis(methylid)]-Komplexe des Nickels, Palladiums und Platins (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3311-3317 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Monomeric Bis[dialkylphosphonium bis(methylide)] Complexes of Nickel, Palladium, and PlatinumThe reaction of bis(trimethylphosphane) complexes of NiCl2 and PdCl2 with the bulky ylide CH3[(CH3)3C]2P = CH2 in a molar ratio 1:4 leads to transylidation and formation of corresponding phosphonium salt and the new ylide chelates [(CH3)3C]2P(CH2)2M(CH2)2P[(CH3)3]2; M = Ni (1); M = Pd (2). In similar experiments with PtCl2, only the salt-like half-complex [(CH3)3C]2P(CH2)2Pt[P(CH3)3]2+Cl¯ (3) is obtained. However, the reaction of the lithiated ylide with (l,5-cyclooctadiene)PtCl2 yields the missing Pt analogue of the above type (4). Contrary to the results with Pd11, Ni11 reacts with 1 -methyl- l-methylene-λ.5-phospholane and -phosphorinane to give monomeric bis-chelates of the formula CH2]nP(CH2):Ni(CH2)2:P[CH2]n; n = 4 (5): n = 5 (6). The monomeric Structure was confirmed by 1H, 13C, 31P NMR, and mass spectra, and attributed to steric effects in the case of the tert-butyl compounds. The opening of the CPC chelate angle induced by the strained ring system of the cyclic ylides appears to favour pseudo-allyl type interactions with the nickel centre.
    Notes: Die Bis(trimethylphosphan)-Komplexe von NiCl2 und PdCl2 reagieren mit dem sterisch anspruchsvollen Ylid CH3[(CH3)3C]2P≡CH2 im Molverhältnis 1:4 unter Umylidierung zum zugehörigen Phosphoniumsalz und den neuen Ylid-Chelaten [(CH3)3C]2P(CH2)2M(CH2) P[2CH3)3 M] ≡Ni (1), M = Pd (2). Mit PtCl2 entsteht dagegen bei deràrtigen Ansätzen nur der salzartige Halbkomplex [(CH3)3C]2P(CH2)2Pt[P(CH3)3]2-;Cl+ (3). Die Reaktion des lithiierten Ylids mit (l,5-Cyclooctadien)PtCI2 liefert dagegen das fehlende Pt-Analoge des obigen Typs (4). - lm Gegensatz zu den Verhältnissen bei Pd11 ergibt NiII auch mit l-Methyl-l-methylen-λ5-phospholan und -phosphorinan monomere Doppelchelate der Formel [CH2]nP(CH2)2Ni(CH2)2P[CH2]n: n = 4(5), n = 5 (6). Die Monomerstruktur wurde durch 1H. 13C, 31P-NMR- und Massenspektren gesichert und bei den tert-Butyl-Verbindungen durch sterische Effekte gedeutet. Bei den cyclischen Yliden begünstigt die starke Winkelöffnung der Chelateinheit eine Pseudo-Allylwechselwirkung mit dem Nickelzentralatom.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791121004
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    Reaktivität von Metall-Metall-Bindungen. Wiederholte Schließung und Öffnung einer Fe - Co-Bindung durch Eliminierung und Addition (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3390-3412 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactivity of Metal-Metal Bonds. Repeated Formation and Cleavage of a Fe - Co Bond by Elimination and AdditionIn arsenic-bridged dinuclear metal carbonyl complexes the sequence of formation and cleavage of the metal-metal bond by elimination of CO and addition of a phosphine ligand is repeatable. Starting from (CO)4Fe -AsMe2 - Co(CO)4 it can be performed four times in a row. The ligand which in each case is introduced at the cobalt atom can be transferred to the iron atom by isomerisation in complexes with and without metal-metal bonds. With Pme3 and P(OMe)3 as phosphines and up to the introduction of three ligands thus 44 different complexes are possible of which 35 were isolated (scheme 1). By side reactions or for the purpose of comparisons further complexes with chain-like arrangements of metal and P or As atoms were obtained. When four ligands are introduced the elimination/addition scheme reaches a natural limit since then phosphine elimination is preferred to CO elimination. The described sequences can be understood as basic patterns of catalytic activity by opening of metal-metal bonds.
    Notes: In arsenverbrückten Metallcarbonyl-Zweikernkomplexen ist die Sequenz von Bildung und Lösung der Metall-Metall-Bindung durch Eliminierung von CO und Addition eines Phosphanliganden wiederholbar. Ausgehend von (CO)4Fe-AsMe2-Co(CO)4 läßt sie sich viermal hintereinander durchführen. Der jeweils am Cobaltatom eingeführte Ligand kann in Komplexen mit und ohne Metall-Metall-Bindung durch Isomerisierung auch auf das Eisenatom übertragen werden. Mit PME3 und P(OMe)3 als Phosphanen sind so bis zur Einführung von drei Liganden 44 verschiedene Komplexe denkbar, von denen 35 isoliert wurden (Schema 1). Durch Nebenreaktionen bzw. zu Vergleichszwecken wurden weitere Komplexe mit kettenförmiger Anordnung von Metall- und P- bzw. As-Atomen erhalten. Nach der Einführung von vier Liganden findet das Eliminierungs/ Additions-Schema eine natürliche Grenze, da dann Phosphan-Eliminierung gegenüber der CO-Eliminierung bevorzugt wird. Die beschriebenen Sequenzen lassen sich als Grundmuster katalytischer Aktivität durch Öffnung von Metall-Metall-Bindungen verstehen.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791121008
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  • 114
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    Darstellung und Eigenschaften von Carbamoyleisen-Komplexen; Kristallstruktur von Nickelbis[tetracarbonyl-μ-(dimethyl-carbamoyl-O)-eisen] (2 Ni-Fe) (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3413-3423 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Properties of Carbamoyliron Complexes;. Crystal Structure of Nickelbis[tetracarbonyi-μ-(dimethylcarbamoyl-O)-iron](2M-Fe)The carbamoyl complex 1 can be transaminated with piperidine and pyrrolidine to give 2 and 3. 1-3 react with anhydrous nickel bromide to yield the nickelbis[tetracarbonyl-μ-(carbamoyl-O)-iron] (2 Ni-Fe) complexes 4-6, which are studied by spectroscopic methods. The X-ray analysis proves a linear iron nickel iron spine in 4. The crystals are triclinic, space group PT, with one molecule in the unit cell.
    Notes: Der Carbamoylkomplex 1 läßt sich mit Pyrrolidin und Piperidin zu 2 und 3 umaminieren. 1-3 reagieren mit wasserfreiem Nickelbromid zu den Nickelbis[tetracarbonyl-μ-(carbamoyl-0)-eisen](2N - Fei)-Komplexen 4-6, die spektroskopisch untersucht werden. Die Röntgenstrukturanalyse von 4 beweist das Vorliegen einer linearen Eisen-Nickel-Eisen-Anordnung. Die Kristalle sind triklin, Raumgruppe PT, mit einem Molekül in der Elementarzelle.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791121009
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  • 115
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    Zum Mechanismus der Reaktion von 2-Brom-N,N-dimethyl-2, 2-diphenylacetamid mit Natriummethoxid in 2,2-Dimethoxypropan. Eine Methode zum Nachweis des Radikalanion-Radikal-Kettenmechanismus (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3520-3522 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Mechanism of the Reaction of 2-Bromo-N,N-dimethyl-2,2-diphenylacetamide and Sodium Methoxide in 2,2-Dimethoxypropane. A Method for Establishing the Radical-Anion Radical Chain MechanismThermolysis of N,N-dimethyl-2,2-diphenyl-2-(phenylazo)acetamide (1, X = C6H5N≡N-) in the presence of sodium methoxide in 2,2-dimethoxypropane furnishes N,N-dimethyl-2,2-diphenylacetamide (1, X = H), the dimeric product 3, and 2-hydroxymethyl-2,2-diphenylacetamide (1, X = -CH2OH). An analysis of this result leads to the conclusion that the title reaction, which yields compounds 1 (X = H) and 3, is a radical-anion radical chain process.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791121019
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  • 116
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    Zinnorganische Verbindungen des 1,2-Diethinylbenzols (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3552-3558 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Organo Tin Compounds of 1,2-DiethynylbenzeneThe preparation and the properties of the compounds o-C6H4(C≡C — SnR3)2 (R equals; CH3, C6H5),[o-C6H4(C ≡ C)2SnR2]2 (R = CH3, C6H5, 1-Naphthyl; R2 = Pentamethylene), [o-C6H4(C≡C)2)3-(SnC6H5)2]n (n = 2, 8, 〉8) and [(o-C6H4(C≡C)2)2Sn]n (n = 12-15,〉15) are described. The structures of these compounds are supported by their spectra.
    Notes: Darstellung und Eigenschaften der Verbindungen o-C6H4(C≡C — SnR3)2 (R = CH3 C6H5), [o-C6H4(C≡C)2SnR,sb2]2 (R = CH3, C6H5, 1-Naphthyl; R2 = Pentamethylen), [(o-C6H4(C≡C)2)3-(SnC6H5)2]n (n = 2, 8, 〉8) und [(o-C6H4(C≡C)2)2Sn]n (n = 12-15, 〉15) werden beschrieben. Die Konstitutionen der Verbindungen werden spektroskopisch gestützt.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791121104
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  • 117
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    Beiträge zur Chemie der Cycl[4.3.2]azine (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3577-3588 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Chemistry of Cycl[4.3.2]azines1)6-tert-Butyl-4H-3a-aza-4-azulenone (3c) and the cycl[4.3.2]azine derivatives 1d and e are synthesized. Attempts to eliminate the ester groups of 1d and e by thermolysis failed. Using Fe2(CO)9, 1d and e are transformed into the complexes 9a and b. The thermolysis of 9b yields the anhydride 10. 5-Azacycl[4.3.2]azine-4-carbonic esters 11 are obtained of two independent routes. 12 is prepared from 11 and Fe2(CO)9 -From the NMR spectra it is concluded that a paratropic effect exists of the cycl[4.3.2]azine π-system of about 4-5 ppm being largest in the 7-membered ring. The shifts of all protons are affected by the nitrogen atom in perimeter-position 5 of 11, the maximum effect being observed again in the 7-membered ring.
    Notes: 6-tert-Butyl-4H-3a-aza-4-azulenon (3c) und die Cycl[4.3.2]azin-Derivate 1d und e werden dargestellt. Versuche zur thermolytischen Entfernung der tert-Butoxycarbonylgruppen aus 1d und e scheiterten. Mit Fe2(CO)9 konnten aus 1d e die Tricarbonyleisen-Komplexe 9a und b erhalten werden. Die Thermolyse von 9b führte zum Anhydrid 10. 5-Azacycl[4.3.2]azin-4-carbonsäureester 11 werden auf zwei Wegen dargestellt. Aus 11b wurde der Tricarbonyleisen-Komplex 12 erhalten.  - Die1H-NMR-Spektren weisen auf eine durch das Cycl[4.3.2]azin-π-System verursachte Paratropie von etwa 4-5 ppm, welche im Siebenring am größten ist. Der Einfluß des perimeterständigen Stickstoffatoms auf die chemischen Verschiebungen von 11 erstreckt sich über das gesamte Ringsystem und ist ebenfalls im Siebenring am stärksten ausgeprägt.
    Additional Material: 2 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19791121107
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    Polare Cycloadditionen von elektronenreichen Mehrfachbindungssystemen an 1,3,4-Oxadiazolium-Salze: Synthese von 3aH-[1,3,4]Oxadiazolo[3,2-α]chinolinen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3623-3636 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Polar Cycloadditions of Electron-rich Multiple Bond Systems to 1,3,4-Oxadiazolium Salts: Synthesis of 3aH-1,3,4 Oxadiazolol 3,2-α quinolinesThe 1,3,4-Oxadiazolium-salts 6c,g,h,i,j react withN,N-Diethyl-1-propin-1-amin(7) in a [4⊕ + 2]-Cycloaddition to afford the 3aH[1,3,4]Oxadiazolo[3,2-a]quinolines 8 c,g,h,i,j.. A [2⊕ + 2] cycloaddition of diethyl acetylenedicarboxylate with 8i yields the tetracycle 9. Alkaline hydrolysis of 8 leads to the quinolone 10. A [3⊕ + 2]-cycloaddition cycloreversion is observed with 6e, I and 18 yielding (→ 12, 15, 20 + 21) respectively. Ketene diethyl acetal (22) reacts with 6k in the same manner (→ 23)
    Notes: Die 1,3,4-Oxadiazolium-Salze 6c,g,h,i,j reagieren mitN,N-Diethyl-1-amin(7) in einer [4⊕ + 2]-Cycloaddition zu den 3aH[1,3,4]Oxadiazolo[3,2-a]chinolinen 8. Eine [2⊕ + 2] Cycloaddition von Acetlylendicarbonsäure-diethylester an 8i führt zum Tetracyclus 9. Die alkalische Hydrolyse von 8 ergibt die Chinolone 10. Eine [3⊕ + 2]-Cycloaddition-Cycloaddition-Cycloreversion wird bei 6e, I und 18 beobachtet (→ 12, 15, 20 + 21). Auch Keten-diethylacetal (22) reagiert mit 6k in dieser Weise (→ 23).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791121112
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    Alicyclische Verbindungen, II. Darstellung und Photoelektronenspektren der Cyclopropanierungsprodukte von 3,4-Dimethylen-1-cyclobuten (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3691-3702 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Alicyclic Compounds, II. Preparation and Photelectron Spectra of the Cyclopropanation Products of 3, 4-Dimethylene-1-cyclobuteneCyclopropanation of 3, 4-Dimethylene-1-cyclobutene (1) with diazomethane/cuprous chloride in pentane provides the novel spiro compounds 6-methylenespiro[2.3]hex-4-ene (2) and dispiro[cyclopropane-1, 2′-bicyclo[2.1.0]pentane-3′, 1″-cyclopropane] 94) as well as the already known dispiro[2.0.2.2]oct-7-ene (3). The photoelectron spectra of these hydrocarbons have been analyzed.
    Notes: Die Cyclopropanierung von 3,4-Dimethylen-1-cyclobuten (1) mit Diazomethan/Kupfer (I) chlorid in Pentan liefert die neuen Spiroverbindungen 6-Methylenspiro [2.3]hex-4-en (2) und Dispiro[cyclopropan-1,2′-bicyclo[2.1.0]pentan-3′,1″-cyclopropan] (4) sowie das bekannte Dispiro [2.0.2.2]oct-7-en (3). Die Photoelektronenspektren dieser Kohlenwasserstoffe werden diskutiert.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791121117
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  • 120
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    Photolyse von Cycloalkeno-1,2,3-thiadiazolen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3728-3736 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photolysis of Cycloalkeno-1,2,3-thiadiazolesPhotolysis of the title compounds leads to several types of heterocycles: 1,4-dithiins 5, 1,3-dithioles 9, thiophenes 11, and 1,2,4,5-tetrathianes 12. The yields of the reaction routes 1 - VI depend on the ring size of the cycloalkeno-l,2,3-thiadiazoles (table 1).
    Notes: Bei der Photolyse der Titelverbindungen 1a-d werden Heterocyclen der Typen 1,4-Dithiin 5, 1,3-Dithiol 9, Thiophen 11 und 1,2,4,5-Tetrathian 12 isoliert. Die Ausbeute auf den Reaktionswegen I-VI in Abhängigkeit von der Cycloalkeno-l,2,3-thiadiazol-Ringgröße ist von Interesse (Tab. 1).
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791121121
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  • 121
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    NMR-Spektroskopische Untersuchungen zur Kinetik und Thermodynamik reversibler Dissoziationsreaktionen, VII. Direkte Beobachtung der Ionisation und Ionenrekombination von Tritylchlorid in SO2 (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3715-3722 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: NMR Spectroscopic Studies on Kinetics and Thermodynamics of Reversible Dissoziation Reactions VII. Direct Observation of Ionisation and Ion Recombination of Trityl Chloride in SO2The equilibriaWere analyzed in SO2 by 1H NMR spectroscopy at variable temperature in the partially deuterated compound. The ionisation of trityl chloride into the ion pair was kinetically studied by total line shape analysis of the 1H NMR spectra of the deuterated and the nondeuterated compound. The origin of the relatively high barrier (ΔG1≢ ≈ 42 kJ/mol, ΔS1≢ ≈ -90 J/grad mol) is discussed.
    Notes: Die GleichgewichteIn SO2 wurden in der partiell deuterierten Verbindung durch NMR-Spektroskopie bei variabler Temperatur analysiert. Die Ionisierung des Tritylchlorids in das Ionenpaar wurde durch Linienformanalyse der 1H-NMR-Spektren der deuterierten und nichtdeuterierten Verbindung kinetisch untersucht. Die Ursache der relativ hohen Barrieren (ΔG1≢ = 42 kJ/mol, ΔS1≢ = 25 kJ/mol, ΔS1≢ = - 90 J/grad · mol) wird diskutiert.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791121119
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    Diskussion der UV-Spektren von 3-Keto-Δ4,8(14)-Steroiden als Beispiel einer, through space'-Konjugation (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3748-3752 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Discussion of the UV Spectra of 3-keto-Δ4,8(14)-steroids as an Example of a “Through Space” Conjugation
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791121125
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  • 123
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    Über die Thermolyse von 2-Diazo-1,3-diketonen in Gegenwart von Diazoalkanen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3753-3758 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thermolysis of 2-Diazo-1,3-diketones in the Presence of DiazoalkanesDiazodiketones 1 react with diazoalkanes 3 under the conditions of the Wolff rearrangement via the hypothetical diazonium betaines 4 predominantly by 1,4-cyclization to afford the 3-furanones 11 and enol derivatives 12. Competitively, depending on stabilizing substituents, 1,2-cyclization to the cyclopropanone 6 or the acryl ester 9 as well as cyclization without loss of the diazoalkane nitrogen to the pyrazoles 7, 10 may occur. In the case of electron donating aroylarylketenes the 1,3,4-oxadiazolines 8 are obtained. For the latter reaction, an intermediate azo-zwitterion 5 is assumed.
    Notes: Diazodiketone 1 reagieren mit Diazoalkanen 3 unter den Bedingungen der Wolff-Umlagerung über die hypothetischen Diazoniumbetaine 4 in der Regel durch 1,4-Cyclisierung. wobei 3-Furanone 11 und die Enolderivate 12gebildet werden. Mit dieser Reaktion konkurrieren in Abhängigkeit von stabilisierenden Substituenten: die 1,2-Cyclisierung zum Cyclopropanon 6 bzw. dem Acrylester 9; unter Beibehaltung des Diazoalkan-Stickstoffs Cyclisierung zu den Pyrazolen 7, 10; bei Verwendung elektronenreicher Aroylarylketene schließlich Bildung der 1,3,4-Oxadiazoline 8: Für diesen Reaktionsverlauf wird ein intermediäres Azo-Zwitterion 5 angenommen.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791121202
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    Der Einfluß des Dien-1,4-Abstandes auf die Reaktivität bei Diels-Alder-Reaktionen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 883-889 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Significance of Diene-1,4-Distance on the Reactivity in Diels-Alder ReactionsThe reactivity of cyclopentadiene and di-exo-methylene compounds in Diels-Alder reactions is investigated using the frontier molecular orbital method. It is shown that besides the HOMO-LUMO energy difference the diene 1,4-distance plays an important part for the rate of reaction. The shorter this distance is the higher becomes the reactivity. Experimentally this is shown by the rates of reaction of tetracyanoethylene and maleic anhydride with cyclopentadiene and di-exo-methylene compounds 2-6. The 1,4-distance of the latter is known from force field calculations. 1,4-Distance and log k2 exhibit a linear relationship which is supported by theoretical considerations.
    Notes: Die Reaktivität von Cyclopentadien und cis-fixierten Di-exo-methylenverbindungen in Diels-Alder-Reaktionen wird im Rahmen des Grenzorbitalmodells untersucht. Es wird gezeigt, daß neben der Energiedifferenz der dominanten Grenzorbitalwechselwirkung auch der Dien-1,4-Abstand eine wichtige Funktion besitzt. Je kürzer dieser ist, umso reaktiver ist das Dien. Dies zeigt die Kinetik der Umsetzung von Tetracyanethylen und Maleinsäureanhydrid mit Cyclopentadien und den Di-exo-methylenverbindungen 2-6, deren 1,4-Abstand auf Grund von Kraftfeldrechnungen bekannt ist. Zwischen 1,4-Abstand des Diens und log k2 der Cycloaddition besteht ein linearer Zusammenhang, der sich theoretisch begründen läßt.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120313
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    Der Mechanismus der photolytischen Umsetzung von Pyridin mit Bis(trimethylsilyl)quecksilber, ein Beitrag zur metallorganischen Photochemie (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 950-956 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Mechanism of the Photolytic Reaction of Pyridine with Bis(trimethylsilyl)mercury, a Contribution to the Photochemistry with Metal AlkylsThe photolytic generation of N-(trimethylsilyl)pyridinyls 2 or. resp., their 4,4′-dimers from pyridine or its alkyl derivatives and bis(trimethylsilyl)mercury (1) involves surprisingly no free silyl radicals, but passes a long-lived, photoexcited, polar state 1a of the molecule 1. The latter is described more closely. It is complexed stepwise by two molecules of pyridine, and only in the last step free radicals are formed. The possibly more general importance of these findings for photolytic reactions with metal alkyls is pointed out.
    Notes: Die photolytische Bildung von W-(Trimethylsilyl)pyridinylen 2 bzw. ihren 4.4′-Dimeren. aus Pyridin bzw. seinen Alkylverbindungen und Bis(trimethylsilyl)quecksilber (1) verläuft überraschenderweise nicht über freie Silyl-Radikale, sondern über einen längerlebigen, photoangeregten, polaren Zustand la des Moleküls 1, über den nähere Aussagen gemacht werden. Er wird schrittweise durch zwei Moleküle Pyridin komplexiert, worauf erst im letzten Schritt freie Radikale entstehen. Auf die mögliche Bedeutung der Befunde für andere photolytische Reaktionen mit Metallalkylen wird hingewiesen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120318
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    Cyclopropyl-Nachbargruppeneinfluß auf die Brückenkopfreaktivität von Verbindungen mit Bicyclo[2.2.2]octan-Grundgerüst (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 908-935 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cyclopropyl Neighbouring Group Influence on the Bridgehead Reactivity of Compounds with a Bicyclo[2.2.2]octane SkeletonUpon photochlorination with tert-butyl hypochlorite the cyclopropane anellated bicyclo[2.2.2]-octane hydrocarbons 10a and 2a-6a give the bridgehead chlorids 10b and 2b-6b in increasing relative yields. In addition, a more efficient directed synthesis for 2b has been developed. The solvolysis reactions of 2b-6b lead to unrearranged bridgehead derivatives exclusively, the substantially increasing rates in the series 2b-6b indicating, that a cyclopropyl group can stabilize a neighbouring carbenium ion center substantially, even if the system does not possess the best bisected conformation. It is only with a perpendicular arrangement of the axis of the carbenium ion p-orbital and the Walsh orbital at the neighbouring cyclopropyl carbon atom as in 10b that the cyclopropyl group exhibits a destabilizing effect exclusively. Analysis of the kinetic parameters leads to the result, that the skeletons of the intermediate carbenium ions from 2b, 5b and 6b are twisted with respect to those of the starting materials, because this apparently enables the intermediates to gain additional stabilization. However, for 3b and 4b the twisting in the ground and the transition state has to be equally small. For 2b and 5b-6b the twist angle decreases with an increasing number of anellated cyclopropane rings. The same conclusions have been drawn from the interpretation of the 13C-chemical shifts of the free bridgehead carbenium ions 2f and 4f-6f, which have been generated by the reaction of the corresponding chlorides with antimony pentafluoride in sulfuryl chloride fluoride.
    Notes: Bei der Photochlorierung mit tert-Butylhypochlorit entstehen aus den cyclopropan-anellierten Bicyclo[2.2.2]octan-Kohlenwasserstoffen 10a und 2a-6a mit ansteigenden Relativanteilen die Brückenkopfchloride 10b und 2b-6b. Die Solvolysereaktionen von 2b-6b führen ausschließlich zu nichtumgelagerten Brückenkopfderivaten; die in dieser Reihe erheblich ansteigenden Geschwindigkeiten - relativ zum 1-Bicyclo[2.2.2]octylchlorid um bis zu 2.8·108. beweisen, daß eine Cyclopropylgruppe auch bei einer von der optimalen bisektierten Anordnung abweichenden Konformation ein benachbartes Carbeniumionzentrum beträchtlich stabilisiert. Nur bei senkrechter Anordnung der Achsen des Carbeniumion-p-Orbitals und des Walsh-Orbitals am benachbarten Dreiring-C-Atom wie in 10b wirkt die Cyclopropylgruppe ausschließlich destabilisierend. Die Auswertung der kinetischen Parameter ergibt, daß die Gerüste der intermediären Carbeniumionen aus 2b, 5b und 6b im Vergleich zu denjenigen der Ausgangsverbindungen stärker verdrillt sind, weil dies offenbar eine zusätzliche Stabilisierung der Zwischenstufen ermöglicht. Bei 3b und 4b dagegen muß die Verdrillung von Ausgangs- und Übergangszustand gleich gering sein; bei 2b, 5b und 6b wird sie mit zunehmender Zahl anellierter Cyclopropanringe geringer. Zu den gleichen Schlußfolgerungen führt die Interpretation der 13C-chemischen Verschiebungen der freien Brückenkopf-Carbeniumionen 2f und 4f-6f, die aus den entsprechenden Chloriden mit Antimonpentafluorid in Sulfurylchloridfluorid erzeugt wurden.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120316
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  • 127
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    Polycarbonylverbindungen, XXIV. Gemischte „Oxothioxokohlenstoffe“ aus Amiden und Thioamiden der Quadratsäure (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 990-999 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Polycarbonyls, XXIV. Mixed „Oxothioxocarbons“ from Amides and Thioamides of Squaric AcidHydrolysis or sulfhydrolysis of 1,2-or 1,3-Squaric acid diamides or their mono- or dithioderivatives yields sulfur analogues of squaric acid dianion, examples of mixed „oxothioxocarbons“ (5-8). Reaction with electrophiles and nucleophiles as well as spectroscopic data are reported.
    Notes: Durch Hydrolyse bzw. Sulfhydrolyse von 1,2- oder 1,3-Quadratsäurediamiden bzw. ihrer Mono- oder Dithioderivate entstehen Schwefelanaloga des Quadratsäure-Dianions, Vertreter der gemischten „Oxothioxokohlenstoffe“ (5-8). Es werden Reaktionen mit Elektrophilen und Nucleophilen beschrieben und spektroskopische Daten mitgeteilt.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120321
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  • 128
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    Cycloadditionsreaktionen von Heterocumulenen, XVII. Über den Mechanismus der [2+2]-Cycloaddition von Thioketenen mit Azomethinen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1000-1011 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cycloaddition Reactions of Heterocumulenes, XVII. On the Mechanism of the [2+2]-Cycloaddition of Thioketenes with AzomethinesThe thioketene 1 reacts with the azomethines 2a-f to give the β- thiolactames 3a-f, the structures of which were proven by methylation and oxidation leading to 7 and 8/9c Attempts to trap the potential intermediate of the cycloaddition 11 were unsuccessful. Kinetic experiments demonstrate low solvent and substituent effects on the cycloaddition rate. Starting form 1-deuterated and 1-undeuterated 2b a secondary kinetic isotope effect was measured. These results as well as the formation of the sterically disfavoured cycloadduct 3A indicate that in the rate-determining step of the cycloaddition not the „classical“ dipole 11 is formed, but with orbital symmetry -control the dipolar species 14.
    Notes: Das Thioketen 1 reagiert mit den Azomethinen 2a - zu den β-Thiolactamen 3a-f, deren Struktur durch Methylierung zu 7 und Oxidation zu 8/9c belegt wurde. Versuche, die potentielle Zwischenstufe der Cycloaddition 11 abzufangen, verliefen negativ. Nach kinetischen Untersuchungen sind Lösungsmittel-und Substituenteneinflüsse auf die Cycloadditionsgeschwindigkeit gering. Ausgehend von 1-deuteriertem und 1-undeuteriertem 2b wurde ein sekundärer Isotopeneffekt gemessen. Diese Ergebnisse wie auch die Bildung des sterisch ungünstigen Cycloaddukts 3A sprechen dafür, daß im geschwindigkeitsbestimmenden Schritt der Cycloaddition kein „klassischer“ Dipol 11 entsteht, sondern unter Orbitalsymmetrie-Kontrolle die dipolare Species 14.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120322
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  • 129
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    Thiirene als Zwischenstufen der Thermolyse von 1,2,3-Thiadiazolen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1769-1778 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thiirenes as Intermediates in the Thermolysis of 1,2,3-ThiadiazolesThermolysis of the isomeric thiadiazoles 1a or 1b in moist 2,2′-oxydiethanol (3) yields the ketone 6, the thiophene 7, the alkyne 8, and the disulfide 11, the structure of which was determined by an X-ray analysis. In the presence of diphenylacetylene (15) 1a and 1b react to give the thiophenes 16a and 16b in the same ratio. This implies that the primary products of thermolysis, the 1,3-diradicals 13, can be trapped by alkynes. The formation of identical thiophenes from isomeric thiadiazoles 1 can be understood in terms of an equilibrium between the primary fragments 13 via the thiirene 14. Similarly, the ketone 6 seems not to result from 8 but from 14.
    Notes: Bei der Thermolyse der stellungsisomeren Thiadiazole 1a oder 1b in feuchtem 2,2′-Oxydiethanol (3) entstehen das Keton 6, das Thiophen 7, das Alkin 8 und das durch eine Röntgenstrukturanalyse eindeutig aufgeklärte dimere Disulfid 11. In Gegenwart von Diphenylacetylen (15) bilden sich aus 1a und 1b die Thiophene 16a und 16b im selben Verhältnis. Die bei der Thermolyse zunächst entstehenden 1,3-Diradikale 13 können demnach durch Alkine abgefangen werden. Die Bildung identischer Thiophene aus isomeren Thiadiazolen 1 läß sich durch ein Gleichgewicht der Primärfragmente 13 verstehen, das sich über das Thiiren 14 einstellt. Auch das Keton 6 scheint nicht aus 8, sondern aus 14 zu entstehen.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120528
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  • 130
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    Neue helicale Kohlenwasserstoffe, III. Pentaphenylenicene (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1785-1790 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: New Helical Hydrocarbons, III. PentaphenylenicenesSynthesis and properties of o,p-bridged quinquephenyl compounds 5, 6 are reported. The 1H NMR highfield shift of H1 and the temperature independence of some absorptions are interpreted in terms of a more fixed helical arrangement of the o,p-compared with the m,m-bridged compound 4. p-Phenylene rotation as well as plus-minus interconversion are not observed.
    Notes: Synthese und Eigenschaften der endständig in o,p-Stellung verbrückten Quinquephenyl-Verbindungen 5, 6 werden beschrieben. Die 1H-NMR-Hochfeldverschiebungen von H1 und die Temperaturunabhängigkeit einzelner Absorptionen weisen darauf hin, daß die o,p-Verbrückung zu deutlich stärker fixierten Helices führt als die m,m-Klammer in 4. Eine p-Phenylenrotation wird ebensowenig wie eine Plus-Minus-Umwandlung beobachtet.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120530
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  • 131
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    Pyrane, 78. Über Reaktionen von 3-Formylchromonen mit Diphenylketen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1791-1807 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Pyrans, 78. Reactions of 3-Formylchromones with DiphenylketeneThe reaction of 3-formylchromones 3a und b with diphenylketene (1) leads to 3-(diphenylvinyl)-chromones 2a and b as well as to the diphenyl-tetrahydropyrano[4,3-b]benzopyrandiones 4a and b. Treatment with base converts 4 into 2. With nucleophilic reagents 2 and 4 give rise to diphenylvinyl-substituted ketones (9), enamines (11), pyrazoles(10), pyrimidines (12), and 1,5-benzodiazepines (13) as well as to chromanonyl-diphenyl-acetic acid dervatives (16 and 18), benzopyrano[3,2-c]pyridines (21), to benzopyrano[4,3-c]pyrazole and -isoxazole derivatives (22).
    Notes: Die 3-Formylchromone 3a und b reagieren mit Diphenylketen (1) zu den 3-(Diphenylvinyl)- chromonen 2a und b sowie den Diphenyltetrahydropyrano[4,3-b]benzopyrandionen 4a und b. 4 läßt sich mit Basen in 2 überführen. Mit nucleophilen Reagenzien setzen sich 2 und 4 zu diphenylvinyl-substituirten Ketonen (9), Enaminen (11), Pyrazolen (10), Pyrimidinen (12) und 1,5-Benzodiazepinen (13) um sowie zu Chromanonyl-diphenyl-essigsäure-Derivaten (16 und 18), Benzopyrano[3,2-c]pyridinen (21), zu Benzopyrano[4,3-c]pyrazol- und -isoxazol-Derivaten (22).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120531
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    Cycloadditionen von Cyanthioformamiden mit 1,3-Dipolen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1873-1878 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cycloadditions of Cyanothioformamides with 1,3-DipolesThe disubstituted cyanothioformamides 1 add to diazo compounds presumably forming the thiadiazoles 2 which decompose to give the thiiranes 3. These may be desulfurized to the ethylenes 5.1b reacts with diphenylnitrilimine to form the thiadiazoline 6. Nitrile oxides and 1 afford the oxathiazoles 7. The monosubstituted cyanothiaoformamides 8. likewise yield the oxathiazoles 9. which decompose to aryl isothiocyanates and the cyanoformamides 10. The reaction of 1 with phenylazide at 100°C produces the cyanoformamidines 14. probably via the unstable thiatriazolines 11 or 12 and the thiaziridines 13.
    Notes: Die disubstituierten Cyanthioformamide 1 addieren sich an Diazoverbindungen, vermutlich unter Bildung der Thiadiazole 2, die weiter zu den Thiiranen 3 zerfallen. Diese können zu den Ethylenen 5 entschwefelt werden. Mit Diphylnitrilimin bildet 1b das Thiadiazolin 6. Nitriloxide liefern mit 1 die Oxathiazole 7. In gleicher Weise ergeben die monosubstituierten Cyanthioformamide 8 die Oxathiazole 9, die weiter in Arylisothiocyanate und die Cyanformamide 10 zerfallen. Die Reaktion von 1 mit Phenylazid bei 100°C liefert, offenbar über die instabilen Thiatriazoline 11 oder 12 und die Thiaziridine 13, die Cyanformamidine 14.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120538
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    Reaktionen an Indolderivaten, XXXVIII. Dreiringreaktionen in der Indolreihe (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1889-1901 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions with Indole Derivatives, XXXVIII. Cyclopropane Reactions in the Indole SeriesThe acid-catalyzed and the nucleophilic ring-opening of the cyclopropanelactams 1 and 2 studied and their stereospecifity is reported. The ketolactams 22 and 23 obtained via this route represent important intermediates.
    Notes: Die protonenkatalysierte und die nucleophile Ringöffnung der Cyclopropanlactame 1 und 2 werden studiert und die Stereospezifität beschrieben. Die auf diese Weise erhaltenen Ketolactame 22 und 23 sind wichtige Zwischenprodukte.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120540
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    Reaktionen an Indolderivaten XXXVII. Stereoselektive Synthese polycyclischer Cyclopropanderivate in der Indolochinolizin-Reihe (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1879-1888 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions with Indole Derivatives, XXXVII. Stereoselective Synthesis of Polycyclic Cyclopropane Derivatives in the Indoloquinolizine SeriesThe high yield stereoselective synthesis of the pentacyclic cyclopropanelactam 8 is reported.
    Notes: Es wird über eine in guten Ausbeuten verlaufende stereoselektive Synthese des pentacyclischen Cyclopropanlactams 8 berichtet.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19791120539
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    Reaktionen an Indolderivaten, XL. Ein einfacher Zugang zum Yohimbenon (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1913-1915 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactions with Indole Derivatives, XL. Simple Access to YohimbenoneThe enolether 1, obtained by Birch reduction, easily and in high yield gives rise to yohimbenone (6) via hydrolysis followed by formaldehyde cyclization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120542
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    Neue μ-Hydroxo-Übergangsmetallkomplexe, II. Darstellung mehrkerniger Komplexe des Chroms(III) mit dreizähnigen Amin-Liganden. Struktur des μ[cis-Dihydroxo(O,O′)-hydroxo(l,4,7-triazacyclononan)chrom(III)]-di-μ-hydroxobis[(1,4,7-triazacyclononan)chrom(III)]-Kations (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 2837-2846 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Novel μ-Hydroxo-Transition Metal Complexes, II. Preparation of Polynuclear Complexes of Chromium(III) Containing Tridentate Amine Ligands. The Structure of the μ-[cis-Dihydroxo(O,O′)-hydroxo(l,4,7-triazacyclononane)chromium(III)]-di-μ-hydroxo-bis[(1,4,7-triaacyziononane)chromium(III)] CationThe attempted preparation of dinuclear complexes of chromium(III) containing three μ-hydroxo bridges by a condensation reaction of triaquaaminechromium(III) complexes [amine = 1,1,1-tris(aminomethyl)ethane (l) or l,4,7-triazacyclononane (2)] in acidic media yields only di-μ-hydroxo-bis[aquaaminechromium(III)] complexes (3, 4). More drastic reaction conditions afford a trinuclear complex 7 containing four μ-hydroxo bridges and a terminal OH-ligand which is linked to one μ-hydroxo bridge via a very short hydrogen bond contributing substantially to the stability of this cation. A single-crystal X-ray analysis of [Cr3([9]aneN3)3(OH)5]I5 · 5H2O (8) exhibits two different pairs of μ-hydroxo bridges with bond angles of 98 and 126°, respectively. The synthesis of a dinuclear, triply hydroxobridged chromium(III) complex has not been successful.
    Notes: Versuche, zweikernige Komplexe des Chroms(III) mit drei μ-Hydroxobrücken durch Kondensation von Triaquaaminchrom(III)-Komplexen [Amin = 1,1,1-Tris(aminomethyl)ethan (1) Oder 1,4,7-Triazacyclononan (2)] in saurem Medium darzustellen, führen nur zu Di-μ-hydroxo-bis-[aquaaminchrom(III)]-Komplexen (3, 4). Drastischere Reaktionsbedingungen führen zur Bildung eines dreikernigen Komplexes 7 mit vier μ-Hydroxobrücken und einer terminalen OH-Gruppe, die  -  gebunden über eine starke H-Brückenbindung zu einer μ-Hydroxobrücke  -  wesentlich zur Stabilität dieses Kations beiträgt. Eine Röntgenstrukturanalyse von [Cr3([9]anN3)3(OH)5]I5. 5 H2O (8) zeigt die Existenz zweier unterschiedlicher Paare von μ-Hydroxobrücken in dem dreikernigen Kation mit -Bindungswinkeln von 98 bzw. 126°. Die Synthese eines zweikernigen Tri-μ-hydroxo-Komplexes des Chroms(III) gelang nicht.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120810
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    Physiological cell death of secretory ameloblasts in the rat incisor (1979)
    Springer
    Cell & tissue research 197 (1979), S. 443-451 
    Details
    ISSN: 1432-0878
    Keywords: Ameloblasts ; Cell death ; Incisors ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The migration of the ameloblasts in the continuously erupting incisors of the rat is accompanied by cell loss. Ameloblasts degenerate near the mesial and lateral cemento-enamel junctions in the secretory zone and in the middle two thirds of the region of postsecretory transition, degeneration being most marked where these areas merge. These findings support the hypothesis that the prism decussation in the enamel results from alternating transverse rows of secretory ameloblasts sliding past each other whilst elaborating their rods. The distribution of the degenerating cells suggests, however, that the sliding cell rows are not exactly transverse but arcuate, with the opening facing incisally. The progress of structural alterations of the nuclei in the degenerating ameloblasts appears to follow the pattern earlier described in vinblastine-damaged ameloblasts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233569
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    Experimental studies of apocrine secretion in the dorsal prostate epithelium of the rat (1979)
    Springer
    Cell & tissue research 198 (1979), S. 145-158 
    Details
    ISSN: 1432-0878
    Keywords: Dorsal prostate gland ; Rat ; Apocrine secretion ; Prolactin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Rat dorsal prostate epithelium was studied in intact adult animals, in animals castrated for three days and in rats after inhibition of prolactin secretion. Thin sections, electron-microscopic autoradiographs and freeze-fracture replicas were used to analyze the process of apocrine secretion in this gland. The rough endoplasmic reticulum and the Golgi apparatus of the secretory cells are well developed, but secretory granules are absent. The only sign indicating release of secretory material is the appearance of blebs originating from the apical plasma membrane. Freeze-fracture replicas of the apical plasma membrane reveal that the blebs develop randomly from the bases of microvilli-like protrusions. In vitro pulse labeling of the proteins using 3H-leucine resulted in a labeling of the apical blebs. A post-castration period of three days was sufficient to reduce drastically the number and size of the apical blebs concomitant with regressive changes of the cell. Suppression of prolactin secretion for three weeks by application of lisuride, a synthetic ergot alkaloid, also induced regressive changes in the secretory cells. The apical blebs were still present, but they were shrunken and their content appeared condensed. These experimental conditions proved that the apical blebs are closely related to the functional activity of the cells and are interpreted as true apocrine secretion in the rat dorsal epithelium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234842
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    Nuclear inclusions in paraventricular nucleus neurons of the rat hypothalamus (1979)
    Springer
    Cell & tissue research 203 (1979), S. 223-229 
    Details
    ISSN: 1432-0878
    Keywords: Nuclear inclusions ; Neurons ; Paraventricular nucleus ; Hypothalamus ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary This paper deals with the ultrastructure of two types of intranuclear inclusions, “microfilamentous spindle-shaped” and “crystalloid”, present in paraventricular nucleus neurons of adult normal rats. These inclusions appear occasionally in some non-secretory neurons of the parvocellular system, but have never been seen in neurosecretory cells of the magnocellular system. The microfilamentous spindle-shaped inclusions show a close spatial relationship with the granulofibrillar body and interchromatin granules. The distribution and functional significance of such structures are discussed in the light of recent ultrastructural and biochemical studies on nuclear inclusions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00237236
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  • 140
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    Quantitative radioautographic light and electron microscopic analysis of the localization of monoamines in the median eminence of the rat (1979)
    Springer
    Cell & tissue research 203 (1979), S. 469-485 
    Details
    ISSN: 1432-0878
    Keywords: Median eminence ; Rat ; Catecholamines ; Quantitative light and electron microscopic radioautography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary By means of light and electron microscopic radioautography a quantitative study of the regional distribution of catecholamines in the median eminence of the rat was carried out. One hour after intraventricular injection of 3H-dopamine the highest radioautographic reaction was recorded in the external zone, especially in the lateral palisade zone where many neurosecretory terminals are separated from the basal lamina of the portal pericapillary space by a glial “cuff”. This area showed the highest percentage (52%) of labelled catecholamine containing neurosecretory terminals as well as the maximal silver grain density per one terminal. In the medial palisade zone where direct neurovascular contacts with the capillary loops prevail, only 27 per cent of neurosecretory terminals were found to harbour tritiated dopamine. On the average 35 per cent of neurosecretory terminals in the median eminence of the rat contain catecholamines (both dopamine and noradrenaline). Pretreatment of animals with reserpine strongly reduced the binding of the label. Per cent of labelled neurosecretory terminals as well as grain density over terminals were decreased in both the medial and lateral palisade zones, although to a lesser degree in the latter. The site of origin of catecholamine fibers as well as the mode of catecholamine action at the level of the median eminence are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233275
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  • 141
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    Demonstration of a somatostatin-like activity in retinal cells of the rat (1979)
    Springer
    Cell & tissue research 204 (1979), S. 127-140 
    Details
    ISSN: 1432-0878
    Keywords: Somatostatin-like activity ; Retina ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A somatostatin-like substance is demonstrated by light microscopic immunohistochemistry (PAP-method) in perikarya and cell processes of the retina of adult and infant rats. These perikarya are identified according to their size, arrangement and distribution. Each of the first two neuronal orders (receptors, bipolar cells, ganglionic cells) of the visual pathway can be associated with retinal cells reacting positively with anti-somatostatin. In the adult rat, perikarya and processes of (i) horizontal cells, (ii) amacrine cells and (iii) large neurons in the ganglionic layer are specifically labeled. The staining of middle-sized and small ganglion cells is probably caused by the close attachment of labeled fibers to non-reacting cells. Postnatally, the immunoreactive elements develop in parallel to the differentiation of the corresponding retinal layers. It is discussed whether the three types of retinal cells containing a somatostatin-like substance provide an inhibitory system to each of the two orders of retinal neurons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235169
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  • 142
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    Effects of heat acclimation on the secretory products of the submaxillary gland of the rat (1979)
    Springer
    Cell & tissue research 196 (1979), S. 147-151 
    Details
    ISSN: 1432-0878
    Keywords: Submaxillary salivary gland ; Secretory granules ; Glycoproteins ; Effect of heat ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Secretory granule area and glycoprotein concentration of the saliva in the submaxillary gland of rats were measured during various stages of acclimation to heat at 34±1° C. Granule size decreased by 18% during the first five days of heat acclimation (0.025〈p〈0.05) after which period it increased to reach 118% of the control levels after 28 days (p〈0.05). Glycoprotein concentration in the saliva of stimulated glands rose above control levels, reaching a maximum between the 2nd and 5th day of acclimation (p〈0.05). It was concluded that the initial decrease in granule size reflects a decrease in glycoprotein content following an increase in salivary flow known to occur at high ambient temperatures. The subsequent increase in granule size is considered an adaptation of the gland to continuous stimulation. The rise in salivary glycoprotein concentration suggests increased efficiency of the secretory mechanism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236355
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  • 143
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    A system of intraependymal cisternae along the margins of the median eminence in the rat: Structure, three-dimensional arrangement and ontogeny (1979)
    Springer
    Cell & tissue research 196 (1979), S. 163-173 
    Details
    ISSN: 1432-0878
    Keywords: Hypothalamus ; Median eminence ; Intraependymal cisternae ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Structure, three-dimensional arrangement and ontogeny of large intracellular cisternae located in the median eminence region of the rat hypothalamus were studied using toluidin-blue stained semithin sections and electron microscopy. The cisternae occur along the projections of ependymal cells lining the ventral portion of the third ventricle (infundibular recess). Small cisternae can be seen close to the ventricle, whereas larger ones, divided into smaller compartments by thin septa, cluster near the surface of the hypothalamus. The cisternae are encompassed by a thin layer of cytoplasm to which axon terminals containing synaptic and dense core vesicles are closely related. Cisternae are arranged around the median eminence in a characteristic pattern. They occupy the midline in the retrochiasmatic area, flank both margins of the median eminence and extend caudally behind the origin of the pituitary stalk. The cisternae appear first between the 15th and 17th postnatal days. At about the 30th day their size and distribution resemble the situation observed in adult animals. The ependymal cisternae are suggested to be closely related to the luteinizing-hormone releasing-hormone (LH-RH)-containing fibers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236357
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  • 144
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    Maturation of the hypothalamo-neurohypophysial system (1979)
    Springer
    Cell & tissue research 197 (1979), S. 337-346 
    Details
    ISSN: 1432-0878
    Keywords: Development ; Median eminence ; Neurohypophysial hormones ; Corticotrophin releasing factor ; Immunoperoxidase histochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Transverse sections of the median eminence from fetal and neonatal rats were examined by the immunoperoxidase technique to detect the presence of oxytocin, vasopressin and neurophysin. Neurophysin was observed in the 18-day fetus. Vasopressin and oxytocin were not detected until after birth, on the 4th and 8th days respectively. There was an accumulation of material crossreactive with neurophysin and vasopressin antibodies in the palisade layer of the median eminence between the 4th and 9th days after birth. This distribution of immunoreactive material in the palisade layer was suggestive of neurosecretory substances localized in two fibre tracts on either side of the median eminence. The data are consistent with the accumulation of corticotropin releasing factor and an associated neurophysin in this area. It is suggested that the accumulation of material occurs because of the relative immaturity of the capillary loops that constitute the primary plexus of the hypophysial portal system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233924
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  • 145
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    Identification of G6PDH-active sinusoidal cells as Kupffer cells in the rat liver (1979)
    Springer
    Cell & tissue research 196 (1979), S. 237-247 
    Details
    ISSN: 1432-0878
    Keywords: Liver ; Kupffer cells ; G6PDH activity ; Histochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The aim of this study was to identify the G6PDH-active sinusoidal cells in the rat liver described by Rieder et al. (1978). Because of their number and distribution in the liver parenchyma, endothelial cells and pit cells could be excluded. Fat-storing cells were specifically marked by vital staining with vitamin A and identified by fluorescence microscopy. Kupffer cells could be detected after vital staining with carmine. Both staining methods allowed a subsequent incubation for the demonstration of G6PDH activity in the same unfixed cryostat section. Whereas more than 80% of the fluorescent particles were found outside the enzyme-positive cells, all G6PDH-active cells contained carmine particles. After counting the G6PDH-active cells, an estimation of 0.217 × 108 cells/g liver tissue was obtained. The results indicate that high G6PDH activity is common to all Kupffer cells, and is therefore a highly specific marker enzyme for this class of sinusoidal liver cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00240099
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  • 146
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    The neurosecretory hypothalamo-hindbrain pathway and its possible significance for the regulation of blood pressure and the milk-ejection reflex (1979)
    Springer
    Cell & tissue research 196 (1979), S. 321-336 
    Details
    ISSN: 1432-0878
    Keywords: Neurosecretion ; Hypothalamo-hindbrain pathway ; Rat ; Blood pressure ; Milk ejection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 1. In lactating rats and in rats deprived of water, the amount of neurosecretory material in the fibres of the neurosecretory hypothalamohindbrain pathway exceeds that in untreated control animals. Under these experimental conditions the pathway and its target regions can be well analysed by means of fluorescence and electron microscopic methods. 2. The axons belonging to the hypothalamo-hindbrain pathway originate from perikarya located in the caudal portion of the nucleus paraventricularis and also from a small group of perikarya in the caudo-lateral hypothalamus. On the way to the hindbrain the neurosecretory fibres join other fibre bundles of the mid- and hindbrain. 3. In the hindbrain most of the neurosecretory fibres terminate in the area of the nucleus tractus solitarii and in the area of the dorsal column nuclei. The axon terminals form synapses with other neurones. 4. Using cytochemical methods at the ultrastructural level (Naumann and Sterba, 1976), the authors were able to prove that the vesicles in the exohypothalamic fibres and in their synaptic terminals contain the same sort of material as the neurophysin vesicles in the posterior lobe of the hypophysis. 5. The most distinct increase in neurophysin was observed in lactating females which were separated from their sucklings after a normal lactation period of 15 days and killed four days thereafter, and in rats deprived of water for different time periods. 6. The relationship of the neurosecretory hypothalamo-hindbrain pathway to the nucleus tractus solitarii and to the dorsal column nuclei suggests that, functionally, there may be a correlation between the system of blood-pressure control and the milk ejection reflex.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00240105
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  • 147
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    Syntheses of DL-Serine and of Precursors thereof (Glycolaldehyde and “Masked” Glycolaldehydes) (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 148-160 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesen von DL-Serin Vorläufern (Glycolaldehyd und „maskierte“ Glycolaldehyde)Bei Behandlung von Vinylchloridepoxid (4) mit Wasser, von Chlorethylencarbonat (9) mit wäßrigen Basen, von Vinylacetat (1) oder Ethylvinylether (6) mit wäßrigem Kaliumchlorat und einer katalytischen Menge Osmiumtetroxid bildete sich Glycolaldehyd (5) (Schema 1). Der nicht isolierte Aldehyd 5 lieferte bei der Zelinsky-Stadnikoff-Aminosäure-Synthese DL-Serin mit 70% Ausbeute. Diese Methode ergab, direkt von den „maskierten“ Glycolaldehyden 2, 7, 9, 10, Vinylencarbonat (11), 13 oder 14 ausgehend, ebenfalls DL-Serin (Ausbeuten 35-70%), wogegen ausgehend von 4 kein Serin nachgewiesen werden konnte.
    Notes: On treatment of vinyl chloride epoxide (4) with water, of chloroethylene carbonate (9) with aqueous bases, of vinyl acetate (1) or ethyl vinyl ether (6) with aqueous potassium chlorate and catalytic amounts of osmium tetroxide, glycolaldehyde (5) was formed (scheme 1). The not isolated aldehyde 5, when submitted to the Zelinsky-Stadnikoff amino acid synthesis, afforded DL-serine in 70% yield. The latter method, when applied directly to the “masked” glycolaldehydes 2, 7, 9, 10, vinylene carbonate (11), 13 or 14, also gave DL-serine (yields 35-70%), whereas with 4 no serine formation could be detected (scheme 1).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120115
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  • 148
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    Die Umlagerung des 9-Cyan-cis-bicyclo[6.1.0]nona-2,4,6-trien-9-yl-Anions in das 9-Cyanbicyclo[4.2.1] nona-2,4,7-trien-9-yl-Anion Zur Frage der Bicycloaromatizität (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 175-195 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Rearrangement of the 9-Cyano-cis-bicyclo [6.1.0]nona-2,4,6-trien-9-yl Anion to the 9-Cyanobicyclo[4.2.1]nona-2,4,7-trien-9-yl Anion On the Problem of BicycloaromaticityReaction of methyl cis-bicyclo[6.1.0]nona-2,4,6-triene-9-anti-carboxylate (5b) with lithiumdiisopropylamide does not lead to deprotonation at C9 of 5b. Instead, a bridgehead cyclopropyl anion is formed which opens to give the allyl anion 12b.  -  In contrast, cis-bicyclo[6.1.0]nona-2,4,6-triene-9-anti-carbonitrile (5c) is also deprotonated at C9 leading to the 9-cyano-cis-bicyclo-[6.1.0]nona-2,4,6-trien-9-yl anion (1c), which rearranges comparatively fast (ΔG≠-43°C = 16.5 kcal · mol-1) to the 9-cyanobicyclo[4.2.1]nona-2,4,7-trien-9-yl anion (4c). Applying qualitative MO arguments of Goldstein and Hoffmann 4) one could explain the facile formation of the „bicyclo-aromatic“ 4c on the basis of ground state destabilization of 1c and stabilization of 4c. H/D-Exchange experiments, however, are at variance with this interpretation.  -  An additional stabilization of the transition state in the anionic sigmatropic rearrangement 1c → 4c as well as the opening the C1 — C9 bond instead of the central C1 — C8 bond are in agreement with HOMO-LUMO interactions.
    Notes: Die Umsetzung von cis-Bicyclo[6.I.0]nona-2,4,6-trien-9-anti-carbonsäure-methylester (5b) mit Lithiumdiisopropylamid führt nicht zu Deprotonierung an C9 von 5b. Statt dessen wird das Brückenkopfproton Hl abgespalten. Anionische Ringöffnung ergibt das Allyl-Anion 12b.  -  Im Gegensatz dazu wird das entsprechende 9-anti-Carbonitril 5c auch an C9 zum 9-Cyan-cis-bicyclo[6.1.0]nona-2,4,6-trien-9-yl-Anion (lc) deprotoniert, das vergleichsweise rasch (ΔG≠-43°C = 16.5 kcal · mo1) in das 9-Cyanbicyclo[4.2.1]nona-2,4,7-trien-9-yl-Anion (4c) umlagert. Qualitative MO-Überlegungen nach Goldstein und Hoffmann4) lassen vermuten, daß die leichte 1,5-Umlagerung auf Grundzustands-Destabilisierung von lc bzw. -Stabilisierung von 4c, mithin auf „Bicycloaromatizität“ von 4c, zurückzuführen ist. H/D-Austauschversuche zur Bestimmung von Anion-Stabilitäten stehen jedoch zu dieser Erklärung im Widerspruch.  -  Eine zusätzliche Stabilisierung des Übergangszustandes der anionischen sigmatropen Umlagerung 1c → 4c wie auch die seitliche statt der zentralen Bindungslösung im cyan-substituierten Anion 1c sind mit HOMO-LUMO-Wechselwirkungen zu verstehen.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120117
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  • 149
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    Thieno[3,4-c]isothiazol. Synthese und Eigenschaften eines neuen nichtklassisch kondensierten Thiophens (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 260-265 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thieno[3,4-cisothiazole]. Synthesis and Properties of a New Nonclassical Condensed ThiopheneThe triphenylthieno[3,4-c]isothiazole 3 is a new 10 π heteroarene containing two different masked 1,3-dipolar systems. Its synthesis from 4-phenyl-1,3.2-oxathiazolylium-5-olate (1) and dibenzoyl-acetylene via the direct precursor 2 as well as its photoelectronic and electronic spectra are desribed. The observed electronic transitions of 3 are compared with the results of a PPP-CI calculation
    Notes: Das Triphenylthieno[3,4-c]isothiazol 3 ist ein neuer 10 π-Heteroaromat, der zwei verschiedene maskierte 1,3-dipolare Systeme beinhaltet. Seine Synthese aus 4-Phenyl-1,3,2-oxathiazolylium-5-olat (1) und Dibenzoylacetylen über die direkte Vorstufe 2 sowie sein Photoelektronen- und Elektronenspektrum werden beschrieben. Die an 3 beobachteten Elektronenübergänge werden mit den Ergebnissen einer PPP-CI-Rechnung verglichen.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120123
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  • 150
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    Transanulare Wechselwirkungen bei [3.3]Phanen, III. [3.3]Paracyclophan, neue Synthesen, Sessel- und Wannen-Konformation (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 249-259 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Transanular Interactions in [3.3]Phanes, III. [3.3]Paracyclophane, New Syntheses, Chair and Boat Conformation[3.3]Paracyclophane (1) was synthesized via the 2,13-dithia[4.4]paracyclophane (2) by vapor phase pyrolysis of the disulfone 3 obtained from 2. Reaction of 2 with benzyne gave trans- and cis-2,1 l-bis(phenylthio)[3.3]paracyclophane (4 and 5) by Stevens rearrangement. Oxidation to the sulfoxides 6 and 7 and pyrolysis yielded the [3.3]paracyclophanedienes (12/13) giving 1 on catalytic hydrogenation. Large substituents in the 2,11-positions of the bridges stabilize the two conformers of 1, based on 1H-NMR spectra the trans-isomer 4 has the chair, the cis-isomer 5 the boat conformation.
    Notes: [3.3]Paracyclophan (1) wurde über 2,13-Dithia[4.4]paracyclophan (2) durch Gasphasen-Pyrolyse des aus 2 erhaltenen Disulfons 3 synthetisiert. Reaktion von Dehydrobenzol mit 2 ergab durch Stevens-Umlagerung trans- und cis-2,11-Bis(phenylthio)[3.3]paracyclophan (4 und 5); durch Oxidation zu den Sulfoxiden 6 und 7 und Pyrolyse wurden die [3.3]Paracyclophandiene (12/13) erhalten, die bei katalytischer Hydrierung 1 ergaben. Große Substituenten in den 2,11-Positionen der Brücken stabilisieren die beiden Konformere von 1, laut 1H-NMR-Spektren liegt das trans-Isomere 4 in der Sessel-, das cis-Isomere 5 in der Wannen-Konformation vor.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120122
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    Die Racemisierung spirocyclischer Pentaarylderivate von Elementen der V. Hauptgruppe, I. 1H-NMR-Untersuchungen mit sterisch überbesetzten asymmetrischen Phosphoranen, Arsoranen und Stiboranen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 281-291 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Racemization of Spirocyclic Pentaaryl Derivatives of Group 5 A Elements. I H NMR Investigations with Overcrowded Asymmetric Phosphoranes, Arsoranes, and StiboranesThe two different methyl positions of bis-2,2′-biarylylenephosphorane 7, the corresponding arsoranes 8a, b, and the analogous stiborane 9 are reversibly equilibrated at elevated temperatures with free enthalpies of activation of 18.2 (76.0), 17.2 (72.2), ≈ 22.5 (94.2), and 15.4 (64.6) kcal(kJ)/mol. Starting with the trigonal bipyramidal ground state conformations C and ∪ (fig. 2) these ligand exchange phenomena can be interpreted in the framework of the pseudorotation process on the basis of trigonal bipyramidal transition states of type A with diequatorial biarylylene groups.
    Notes: Die beiden unterschiedlichen Methyl-Positionen des Bis-2,2′-biarylylenphosphorans 7, der entsprechenden Arsorane 8a, b und des analogen Stiborans 9 werden bei erhöhten Temperaturen mit freien Aktivierungsenthalpien von 18.2 (76.0), 17.2 (72.2). ≈ 22.5 (94.2) und 15.4 (64.6) kcal(kJ)/mol reversibel äquilibriert. Ausgehend von den trigonal-bipyramidalen Grundzustandskonformationen C und ∪ (Abb. 2) lassen sich diese Ligandenaustauschphänomene im Rahmen des Pseudorotationsprozesses auf der Basis trigonal-bipyramidaler Übergangszustände des Typs A (Abb. 2) mit diäquatorialen Biarylylen-Gruppen interpretieren.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120125
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    Lichtinduzierte Reaktionen, XIII. Über das seco-isomere Dienylketen aus 2,4-Androstadien-l-on (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 310-348 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Light-induced Reactions, XIII. On the Seco-isomeric Dienylketene Related to 2,4-Androstadien-1-oneThe steroidal 2.4-cyclohexadienone 3 photochemically affords the diastereomer 4. Both the configurational isomers differ exceedingly in their chiroptical properties. Their respective contribution to the photostationary state depends on the wave-length of the light and the solvent utilized. The dienylketene 5 can be determined spectroscopically as a transient. It is not trapped by 2,2,2-trifluoroethanol; cyclohexylamine, however, furnishes the 1,6-adduct 7a and/or the 1,2-adduct 6 a owing to the concentration and wave-length (365 or 313 nm) used.
    Notes: Das steroidale 2,4-Cyclohexadienon 3 geht photochemisch in das Diastereomere 4 über. Beide Konfigurationsisomere unterscheiden sich deutlich in ihren chiroptischen Eigenschaften. Ihr jeweiliger Anteil im photostationären Zustand hängt von der Wellenlänge des Lichts und dem Lösungsmittel ab. Das Dienylketen 5 läßt sich als Transient spektroskopisch nachweisen. Es wird von 2,2,2-Trifluorethanol nicht, von Cyclohexylamin je nach Konzentration und Wellenlänge (365 oder 313 nm) als 1,6-Addukt 7a und/oder als 1,2-Addukt 6a abgefangen.
    Additional Material: 21 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120129
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    Cyclisierungsprodukte aus N-arylsubstituierten Propiolamidinen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 384-388 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cyclic Substances from N-Aryl-substituted PropiolamidinesThe chloroformamidines 4a-c react with lithium phenylacetylide to form the propiolamidines 5a-c. 5a and 5b cyclize upon treatment with polyphosphoric acid to give the 2-aminoquinolines 6 and 7,8, respectively; 5c yields only the spiro compound 9.
    Notes: Die Chlorformamidine 4a-c reagieren mit Lithium-phenylacetylid zu den Propiolamidinen 5a-c. 5a bzw. 5b cyclisieren in Polyphosphorsäure (PPS) zu den 2-Aminochinolinen 6 bzw. 7 und 8, während 5c als einziges Produkt die Spiroverbindung 9 ergibt.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120134
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    Konstitutionsaufklärung des Melochinins, eines Pyridon-Alkaloids neuen Typus aus Melochia pyramidata L. (Sterculiaceae) (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 376-383 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Structure of Melochinine, a New Type of a Pyridone Alkaloid from Melochia pyramidata L. (Sterculiaceae)Melochinine, isolated from leafs of Melochia pyramidata L., is the first representative of a so far unknown class of pyridone alkaloids. Its structure was determined by spectroscopic methods in combination with microchemical degradation reactions to be 3.
    Notes: Das aus Melochia pyramidata L. isolierte Melochinin gehört einer bisher unbekannten Klasse von Pyridon-Alkaloiden an. Seine Struktur 3 wurde mit spektroskopischen Methoden und mikrochemischen Abbaureaktionen bestimmt.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120133
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  • 155
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    Photochemische Synthese von (η5-C5H5)2V2(CO)5 (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 392-393 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photochemical Synthesis of (η5-C5H5)2V2(Co)5μ-Dicarbonyl-tricarbonylbis[(η5-cyclopentadienyl)vanadium](V-V) (2) has been synthesized in 89% yield by photolysis of tetracarbonyl(η5 -cylcopentadienyl)vanadium (1) in tetrahydrofuran using a falling-film photoreactor.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120136
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  • 156
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    Masthead (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979) 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120201
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  • 157
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    Natürlich vorkommende Terpen-Derivate, 156. Über eine neue Gruppe von Sesquiterpenlactonen aus der Gattung Trixis (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 435-444 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Naturally Occurring Terpene Derivatives, 156. On a New Group of Sesquiterpene Lactones from the Genus TrixisTwo species of the South American genus Trixis afforded 12 new sesquiterpenes all with a new pentacyclic ring system, named trixikingolide (3-8 and 10-24). The structures are elucidated by spectroscopic methods and chemical transformations which are in part unusual. The carbon skeleton is that of an isocedrene (1), first found in several other genera of the tribe Mutisieae. This type is probably of chemotaxonomical importance.
    Notes: Zwei Vertreter der südamerikanischen Gattung Trixi ergeben 12 neue Sesquiterpene, alle mit dem neuen pentacyclischen Ringsystem. das wir Trixikingolid genannt haben (3-8 und 19-24). Die Konstitutionen werden durch spektroskopische Methoden und chemische Umwandlungen, die zum Teil ungewöhnlich sind, geklärt. Das Kohlenstoffgerüst ist das eines Isocedrens (1), das zuerst in mehreren Gattungen der Tribus Mutisieae gefunden wurde. Dieser Typ ist wahrscheinlich von chemotaxonomischer Bedeutung.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120206
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  • 158
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    Reaktionen von Azidocobalt(III)-Chelatkomplexen mit Isocyaniden (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 468-479 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Azidocobalt(III) Chelate Complexes with IsocyanidesAzidochelatecobalt(III) complexes N3Co(chelate)B (la-e) [chelate = e. g. dianion of N,N′-o-phenylenebis(salicylidenimine), B = PPh3] react with organic isocyanides to give metal-carbon bonded tetrazolate complexes 3, 4. 2-Isocyanoethanol affords tetrazolato- (9, 10) or azido-oxazolidin-2-ylidene complexes (11), depending on the nature of the solvent, the trans-base B, and the chelate ligand. The mechanism of formation of C-coordinated tetrazoles from azido complexes and isonitriles is discussed.
    Notes: Azidochelatcobalt(III)-Verbindungen N3Co(chelat)B(la-e) [chelat = z. B. Dianion von N,N′-o-Phenylenbis(salicylidenimin), B = PPh3] setzen sich mit organischen Isocyaniden zu Tetrazolatokomplexen 3, 4 mit Cobalt-Kohlenstoff-Bindung um. Mit 2-Isocyanethanol entstehen in Abhängigkeit vom Lösungsmittel, der trans-ständigen Base B und dem Chelatliganden Tetrazolato-(9, 10) oder Azido-oxazolidin-2-yliden-Komplexe (11). Der Mechanismus der Bildung C-koordinierter Tetrazole aus Azidokomplexen und Isonitrilen wird diskutiert.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120209
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  • 159
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    Polycyclische Verbindungen, XII. Vicinale cis-trans-isomere Dihydrodiole in der Hexahydrophenanthren- und -benz[a]anthracen-Reihe (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 532-540 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Polycyclic Compounds, XII. Vicinal cis-trans-Isomeric Dihydrodiols in the Hexahydrophenanthrene and -benz[a]anthracene SeriesThe synthesis of the Vicinal trans-dihydrodiols 3a and 1la in the hexahydrophenanthrene and -benz[a]anthracene series is described. 3a and 1la are obtained by reaction of the oxanorbornadienes 1 and 9 with acetic acid and subsequent alkaline hydrolysis of the trans-hydroxyacetates 3b and 11b. Specific reactions of the cis-trans-isomers 2a and 3a are described.
    Notes: Die Darstellung der vicinalen trans-Dihydrodiole 3a und 11a in der Hexahydrophenanthren-und -benz[a]anthracen-Reihe wird beschrieben. 3a und 11a erhält man durch Reaktion der Oxanorbornadiene 1 und 9 mit Essigsäure und anschließende alkalische Verseifung der trans-Hydroxyacetate 3b und l1b. Spezifische Reaktionen der cis-trans-Isomeren 2a und 3a werden besprochen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120216
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  • 160
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    Synthesen und Reaktionen von L-Olivomycal und L-Mycaral (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 818-822 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Reaction of L-Olivomycal and L-MycaralStarting with L-rhamnal (3) the synthesis of L-olivomycal (4a) is achieved with only few steps and in high yields. Following hydrogenation of 4a and the isomeric side product L-mycaral (5), to the corresponding 1,5-anhydro derivatives 7 and 8, only 8 gave a cis-carbonate 9. This proves the configuration at the branching point C-3 in 4a and in 5. By the reaction of 4b with methanol and N-iodosuccinimide 10b is obtained, which, after subsequent reduction employing nickel boride, gave methyl α-L-olivomycoside (11) in high yield. By application of the same procedure the disaccharide derivative 13 is synthesized without problems.
    Notes: Die Synthese von L-Olivomycal (4a) gelingt in wenigen Reaktionsschritten und guten Ausbeuten ausgehend von L-Rhamnal (3). Nach Hydrierung von 4a und dem isomeren Nebenprodukt L-Mycaral (5) zu den entsprechenden 1,5-Anhydroverbindungen 7 und 8 reagiert nur 8 zu einem cis-Carbonat 9, womit die Konfiguration am Verzweigungspunkt C-3 in 4a und 5 belegt wird. Umsetzung von 4b mit Methanol und N-Iodsuccnimid zu 10b und nachfolgende Reduktion mit Nickelborid gibt Methyl-α-L-olivomycosid (11) in hoher Ausbeute. Gleichermaßen gelingt die glatte Synthese des Disaccharidderivats 13.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120306
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  • 161
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    Kristallstrukturen der Alkali-isopropoxide des Kaliums, Rubidiums und Caesiums (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 844-848 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal Structures of the Isopropoxides of Potassium, Rubidium, and CesiumPotassium-, rubidium- and cesium isopropoxide are isostructural (tetragonal space group P4/nmm-D4h7). Their cell constants have been determined. Using a single crystal the structure of cesium isopropoxide has been determined by X-ray analysis and refined to R = 0.069. The alkoxides form layer structures of the type of lithium respectively sodium methoxide. The metal atoms are arranged in one plane and are coordinated on both sides by O-atoms. each O-atom being surrounded by four metal atoms and one sec. C-atom. The methyl-C-atoms are distributed statistically between two positions differing by a 90° rotation of the (CH3)2CH-group.
    Notes: Die Isopropoxide des Kaliums, Rubidiums und Caesiums sind isostrukturell tetragonale Raum-gruppe P4/nmm-D4h7). Ihre Zellkonstanten wurden ermittelt und die Struktur des Caesium-isopropoxids anhand eines Einkristalls röntgenographisch bestimmt und bis R = 0.069 verfeinert. Die Alkoxide bilden Schichtgitter vom Typ des Lithium- bzw. Natriummethoxids. Dabei liegen die Metallatome in einer Ebene und sind beiderseits von O-Atomen koordiniert, indem jedes O-Atom von vier Metallatomen und einem sec. C-Atom umgeben ist. Die Methyl-C-Atome sind statistisch auf zwei Lagen verteilt, welche sich durch Drehung der (CH3)2CH-Gruppe um 90° unterscheiden.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120309
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  • 162
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    Elektronenstruktur von Alkyl-aryl- und Alkyl-vinyl-ethern (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1614-1625 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Electronic Structure of Alkyl Aryl and Alkyl Vinyl EthersFor the evaluation of the interactions between π electrons of the CC double bond and lone Pairs at the 0 atom of α, β-unsaturated ethers p. e. spectra of some alkyl aryl ethers 1-3 were recorded and compared with those of alkyl vinyl ethers 5. The data could be interpreted by means of orbital correlation diagrams provided the interaction with energetically high-lying σ orbitals of the correct symmetry was taken into account. Sterically hindered alkyl aryl ethers were found to exist in a perpendicular conformation; in sterically unhindered ethers like anisole a less stable isomer having this conformation was detected. In the case of alkyl vinyl ethers non-bonding interactions favour the s-cis conformation, whereas sterically hindered molecules of this type prefer the s-trans form. From p. e. spectra at higher temperatures (up to 510 K) the relative conformational energies are estimated. The results of the p. e. analysis are used for the interpretation of some reactions of α,β-unsaturated ethers.
    Notes: Um das Ausmaß der Konjugation zwischen π-Elektronen der CC-Doppelbindung und freien Elektronenpaaren am O-Atom α, β-ungesättigter Ether zu ermitteln, wurden die Photoelektronenspektren einer Anzahl von Alkyl-aryl-ethern 1-3 aufgenommen und mit den Spektren von Alkyl-vinyl-ethern 5 verglichen. Die Ergebnisse lassen sich mit Hilfe von Orbitalkorrelationsdiagrammen vollständing interpretieren, sofern man energetisch hochliegende σ-Orbitale geeigneter Symmetrie in die Betrachtung einbezieht. Sterisch gehinderte Alkyl-aryl-ether nehmen eine perpendikuläre Konformation ein, die bei sterisch nicht gehinderten Verbindungen wie etwa Anisol als zweite weniger stabile Form gefunden wird. Im Fall der Alkyl-vinyl-ether überwiegt aufgrund einer nichtbindenden Wechselwirkung die s-cis-Konformation bei sterisch nicht gehinderten Ethern, während sonst die s-trans-Konformation bevorzugt wird. Durch die Aufnahme von Photoelektronenspektren bei Temperaturen bis 510 k lassen sich die Energieunterschiede zwischen den verschiedenen Konformeren abschätzen. Die Ergebnisse der PE-Untersuchungen Können zur Interpretation von Reaktionen α,β-ungesättigter Ether herangezogen werden.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120512
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  • 163
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    Beiträge zum Mechanismus der photochemischen Reaktionen von Phenylsydnonen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1635-1649 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Mechanism of the Photochemical Reactions of PhenylsydnonesThe light-induced decay of diphenylsydnone (1a in various solvents and in the presence of benzonitrile or 4-chlorobenzonitrile with evolution of carbon dioxide leads to the formation of a nitrile imine intermediate 4 a, whose products are partially isolated and identified. For example, the isomeric triazoles 5 (2.5%) and 7 (7.9%) beside the oxadiazolinone 6a (0.9%) and the phenylhydrazine 8 a (29 %) are formed during the irradiation 1a in acetone. The phenanthridinone derivative 22 and the N-phenylbenzohydrazide 24 are formed during working up of the irradiation mixture from 1a in pure acetyl chloride. Furthermore, the photolyses of 1b, c in acetone and of 1b or 6b in methanol are described. The formation of the isolated products is discussed.
    Notes: Der lichtinduzierte Zerfall des Diphenylsydnons (1a) in verschiedenen Lösungsmitteln sowie in Gegenwart von Benzonitril oder 4-Chlorbenzonitril liefert unter Kohlendioxid-Abspaltung eine Nitrilimin-Zwischenstufe 4 a, deren Folgeprodukte teilweise isoliert und identifiziert werden. Beispielsweise werden bei der Bestrahlung von 1a in Aceton die isomeren Triazole 5 (2.5%) und 7 (7.9%) neben dem Oxadiazolinon 6 a (0.9%) und dem Phenylhydrazin 8 a (29 %) gebildet. Das Phenanthridinon-Derivat 22 und das N-Phenylbenzohydrazid 24 entstehen bei der Aufarbeitung des Belichtungsansatzes aus 1a in reinem Acetylchlorid. Weiterhin werden die Photolysen von 1b, c in Aceton und von 1b oder 6 b in Methanol beschrieben. Die Bildungsweisen der isolierten Produkte werden diskutiert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120514
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  • 164
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    3-O-Benzyl-D-ribose (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1705-1711 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 3-O-Benzyl-D-ribose3-O-Benzyl-D-ribose (4) is synthesized from D-glucose and D-ribose via different routes; these methods were compared. For a characterization 4 is transformed into 3′-O-benzyl-adenosine (19). 1H NMR data of the synthesized compounds are compiled.
    Notes: Aus D-Glucose und aus D-Ribose wird in vergleichenden Untersuchungen auf verschiedenen Wegen 3-O-Benzyl-D-ribose (4) hergestellt. Zur Charakterisierung wird 4 in 3′-O-Benzyladenosin (19) übergeführt. 1H-NMR-Spektroskopische Daten der synthetisierten Verbindungen werden mitgeteilt.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120520
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    Komplexchemie reaktiver organischer Verbindungen, XXIV. Fünfgliedrige Cobaltacyclen durch Carben-Addition an Dicarbonyl-(η5-cyclopentadienyl)cobalt (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1731-1742 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Complex Chemistry of Reactive Organic Compounds, XXIV. Five-Membered Cobalta Cycles from Carbene Addition to Dicarbonyl (η5-cyclopentadienyl)cobaltPhotolysis of the dialkyl diazomalonates 2a-g in the presence of dicarbonyl(η5-cyclopentadienyl)cobalt (1) in tetrahydrofuran yields the cobalta cycles 3a-g. The formation of the new compounds, established by X-ray structural determination on the case of 3c, can be explained formally as a result of a [2 + 3]-cycloaddition of the carbenes derived from the diazo precursors 2a-g to the organometallic substrate 1. The cyclic cobalt compounds 3a-g are converted by a thermal reaction with 1 through opening of the metalla cyclic structural element into the dinuclear μ-methylene cobalt compounds 4a-g.
    Notes: Durch Photolyse der Diazomalonsäure-dialkylester 2a-g in Gegenwart von Dicarbonyl-(η5-cyclopentadienyl)cobalt (1) in Tetrahydrofuran sind die Cobaltacyclen 3a-g zugänglich. Die Bildung der neuen, am Beispiel von 3c auch röntgenstrukturanalytisch gesicherten Verbindungen ist formal das Ergebnis einer [2 + 3]-Cycloaddition der von den Diazo-Vorstufen 2a-g abgeleiteten Carbene an das Organometall-Substrat 1. Unter Öffnung des metallacyclischen Strukturelements sind die cyclischen Cobalt-Derivate 3a-g bei thermischer Umsetzung mit 1 in die zweikernigen μ-Methylen-Cobalt-Komplexe 4a-g überführbar.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120523
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    Trigonal planar koordinierter Schwefel(VI): Die Kristall- und Molekülstrukturen von (R3SiN)3S und (R3CN)3S (R=CH3) bei -130°C (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1751-1755 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Planar Threefold Coordination of Sulfur(VI): Crystal and Molecular Structures of (R3SiN)3S and (R3CN)3S (R=CH3) at -130°CThe crystal structures of the title compounds were determined from single crystal X-ray data (measured at -130°C) and refined to unweighted R-values of 0.034 for (R3SiN)3S (1) and 0.047 for (R3CN)3S(2). 2 crystallizes in the triclinic space group P1 and 1 in the hexagonal space group P63/m. Both structures exhibit a planar threefold nitrogen coordination of the sulfur but the large coefficients of the temperature factors perpendicular to the SN3 planes in 1 and 2 might indicate a disorder due to small deviations from planarity. The S—N bond lengths were found to be 150.4 (1) and 151.5 pm (2, mean).
    Notes: Die Strukturen der Titelverbindungen wurden aus Diffraktometer-Einkristalldaten (gemessen bei -130°C) bestimmt und zu ungewichteten R-Werten von 0.034 für (R3SiN)3S )(1) und 0.047 für (R3CN)3S (2)verfeinert. 2 kristallisiert triklin, P1. Und 1 hexagonal, P63/m. In beiden Strukturen wird eine trigonal planare Koordination des zentralen Schwefelatoms beobachtet, doch deuten die relativ großen Koeffizienten der anisotropen Temperaturfaktoren senkrecht zu den SN3-Ebenen in 1 und 2 auf eine Fehlordnung als Folge geringer Abweichungen von der Planarität in den einzelnen Molekülen hin. Die S—N-Abstände betragen 150.4 pm (1) und 151.5 pm (2, Mittelwert).
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120525
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    Das Reaktivitäts-Selektivitätsprinzip, 4. Die Selektivität von Alkyl-Radikalen im BrCCl3/CCl4-Konkurrenzsystem (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1743-1750 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Reactivity-Selectivity Principle, 4. Selectivity of Alkyl Radicals in Competition System BrCCl3/CCl4Alkyl radicals were generated from alkylmercuric salts 1 and peresters 4. Their reactions in competition system BrCCl3/CCl4 show that at 273 and 403 K the sequences of radical selectivities are completely reversed. At 273 K the methyl radical is the least selective but at 403 K it is the most selective alkyl radical of table 1. The isoselective temperature lies in the region of 340 K. The reason of this is the opposing influence on activation enthalpies and activation entropies. With increasing alkylation of the radicals, activation enthalpies enlarge but activation entropies reduce the selectivities (table 2). The differences of radical selectivities are governed below the isoselective temperature by variation of activation enthalpies and above the isoselective temperature by variation of activation entropies.
    Notes: Alkyl-Radikale wurden aus Alkylquecksilbersalzen 1 und Perestern 4 erzeugt. Ihre Reaktionen im BrCCl3/CCl4-Konkurrenzsystem zeigen, daß bei 273 und 403 K die Selektivitätsreihenfolge der Radikale einander genau entgegengesetzt ist. Während bei 273 K das Methyl-Radikal das am wenigsten selektive Radikal ist, besitzt es bei 403 K die größte Selektivität aller Alkyl-Radikale der Tab. 1. Die isoselektive Temperatur liegt im Bereich von 340 K Ursache für dieses Verhalten ist der gegenläufige Einfluß auf die Aktivierungsenthalpien und Aktivierungsentropien. Mit zunehmender Alkylierung der Radikale führen die Aktivierungsenthalpien. Zu einer Vergrößerung, die Aktivierungsentropien jedoch zu einer Verkleinerung der Radikalselektivitäten (s. Tab. 2). Unterhalb der isoselektiven Temperatur werden die Unterschiede der Radikalselektivitäten von den Änderungen der Aktivierungsenthalpien, oberhalb der isoselektiven Temperatur von den Änderungen der Aktivierungsentropien bestimmt.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120524
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    Eliminierung von Olefinen aus Iminotriorganylphosphoranen im Ammonosystem (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1756-1762 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Elimination of Olefins from Iminotriorganylphosphoranes in Liquid Ammonia SolutionIn the presence of potassium amide some iminotriorganylphosphoranes (1,2,5-7) react under elimination of olefins. The mechanism of this reaction is discussed.
    Notes: Bei Einwirkung von Kaliumamid in flüssigem Ammoniak spalten einige Iminotriorganylphosphorane (1,2,5-7) im Sinne einer Eliminierungsreaktion Olefin ab. Der Reaktionsmechanismus wird diskutiert.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120526
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    Wasserstoff-Übertragungsreaktionen, III. Wasserstoffübertragungen zwischen o,o′-verknüpften Tetraarylethylenen und Diarylmethanen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1763-1768 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions involving Hydrogen Transfer, III. Hydrogen-Transfer Between o,o′-Bridged Tetraarylethylenes and DiarylmethanesThermal hydrogen transfer between o,o′-bridged diarylmethanes and o,o′-bridged tetraarylethylenes leads to reduction of the ethylenes and to dimerization and dehydrogenation of the diarylmethanes (equ. (1)-(5)). The ethylene 1 reacts with 9,10-dihydroanthracene (15) to form 3 and anthracene (16)[equ. (6)]. The principles of these reaction are discussed.
    Notes: Bei der thermischen Wasserstoffübertragung zwischen o,o′-überbrückten Diarylmethanen und o,o′-überbrückten Tetraarylethylenen werden die eingesetzten Ethylene hydriert und die Diarylmethane dehydrierend dimerisiert (Gleichungen (1)-(5)). Das Ethylen 1 und 9, 10-Dihydroanthracen (15) liefern nach (6) 3 und Anthracen (16) Die Grundlagen dieser Reaktion werden diskutiert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120527
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  • 170
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    Organometallphosphan-substituierte Übergangsmetallkomplexe, XXIV. Organoelement(IVb)-phosphan-Derivate von Octacarbonyldicobalt (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1779-1784 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Organometalphosphine-substituted Transition Metal Complexes, XXIV. Organoelement(IVb)-phosphine Derivatives of OctacarbonyldicobaltOctacarbonyldicobalt (1) reacts with (t-C4H9)3P (2), (t-C4H9)2PH (3), [(CH3)3Si]3P (4),[(CH3)3Ge]3P (5) [(CH3)3Sn]3P (6) and (t-C4H9)2[(CH3)3Si]P (7) with displacement of two CO ligands and formation of corresponding hexacarbonyldi(organoelement)IVb)-phosphine)-cobalt complexes. The vibrational and NMR spectra of the new compounds are discussed.
    Notes: Octacarbonyldicobalt (1) reagiert mit (t-C4H9)3P (2), (t-C4H9)2PH (3), [(CH3)3Si]3P (4), [(CH3)3 Ge]3P (5), [(CH3)3Sn]3P (6) und (t-C4H9)2[(CH3)3Si]P (7) unter Abspaltung von zwei CO-Liganden und Bildung entsprechender Hexacarbonyldi(organoelement(IVb)-phosphan)-cobalt-Komplexe. Die Schwingungs- und Kernresonanzspektren der neuen Verbindungen werden diskutiert.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120529
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  • 171
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    Synthesen biologisch wichtiger Kohlenhydrate, 19. Zur Regioselektivität der vie. cis-Oxyaminierung 3,4-ungesättigter Kohlenhydrate: Gelenkte Synthese von 4-Amino-4-desoxy- und 3-Amino-3-desoxyaldosiden (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 1859-1866 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses of Biologically Important Carbohydrates, 19. On the Regioselectivity of the vic. cis-Oxyamination of 3,4-Unsaturated Carbohydrates: Directed Syntheses of 4-Amino-4-deoxy- and of 3-Amino-3-deoxyaldosidesThe oxyamination of methyl 2-O-benzyl-3,4-dideoxy-α-D-glycero-pent-3-enopyranoside (1) with chloramine-T/[OsO4] yields a 2:1 mixture of methyl 2-O-benzyl-4-deoxy-4-tosylamino- (2) and of methyl 2-O-benzyl-3-deoxy-3-tosylamino-β-L-arabinoside (3). In the presence of a phase transfer catalyst the ratio is 4.5:1. In contrast benzyl 2-O-acetyl-3.4-dideoxy-α-D-glycero-pent-3-enopyrano-side (13) reacts with formation of the corresponding 4-deoxy-4-tosylamino- (14) and 3-deoxy-3-tosylamino-arabinoside 15 in the ratio 1:2. With reference to the preparative importance of this „reversal“ a hypothesis is given for the reasons of the observed regio orientation: in the reaction 1→2 + 3 through space interactions are supposed.
    Notes: Methyl-2-O-benzyl-3,4-didesoxy-α-D-glycero-pent-3-enopyranosid (1) reagiert mit (Chloramin-T/[OsO4 ] zu Methyl-2-O-benzyl-4-desoxy-4-tosylamino- (2) und Methyl-2-O-benzyl-3-desoxy-3-tosylamino-β-L-arabinosid (3) im Verhältnis 2:1. In Gegenwart eines Phasentransfer-Katalysators entstehen die isomeren im Verhältnis 4.5:1. Dagegen führt das Benzyl-2-O-acetyl-3,4-didesoxy-α-D-glycero-pent-3-cyanopyranosid (13) zum entsprechenden 4-Desoxy-4-tosylamino- (14) und 3-Desoxy-3-tosylamino-arabinosid 15 im Verhältnis 1:2. Auf die präparative Bedeutung dieser Umkehrung wird hingewiesen. Für ihre Ursachen wird eine Hypothese entwickelt: als Grund für die Regioorientierung bei 1→ 2 + 3 werden „through space“-Wechselwirkungen angenommen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120536
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  • 172
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    Synthese von (+)-Discadenin und seinem Desamino- und Descarboxy Derivat (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3072-3080 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of i.(+)-Discadenine and its Deamino and Decarboxy DerivativesThe synthesis of L.(+)-discadenine (1) and its deamino (2a) and decarboxy derivatives (2b) is described. Alkylation of N6-N(,3-dimethylallylamino)purine with the bromo compound 4. ethyl 4-bromobutyrate or N-(3-bromopropyl)phthalimide, respectively, leads to the protected purine derivatives 5a-c. The position of alkylation was confirmed by 1H/1.3C NMR spectroscopy and pH dependent UV spectra and was shown to be N-3. The phthaloyl residues of 5a and c are removed by hydrazinolysis and the cleavage of the ester group in 5a and b is accomplished by alkaline hydrolysis. The reaction products 1, 2a and b are characterised by UV, 1H/C NMR, and mass spectra. The spectroscopic data are in full agreement with those of the spore germination inhibitor from Dictyostelium discoideum.
    Notes: Die Synthese von L(+)-Discadenin (1) sowie seinem Desamino- 2a und Descarboxy-Derivat (2 b) wird beschrieben. Alkylierung von N6-(3,3-Dimethylallylamino)purin mit der Bromverbindung 4 bzw. 4-Brombuttersäure-ethylester oder N-(3-Brompropyl)phthalimid führt zu den geschützten Purin-Derivaten 5a-c, deren Substitution an N-3 mit Hilfe der 1H- bzw. 13C-NMR-Spektroskopie und der pH-abhängigen UV-Spektren gesichert wurde. Hydrazinolyse entfernt die Phthaloylreste von 5a und c, alkalische Hydrolyse spaltet den Ethoxycarbonylrest in 5a und c. Die Reaktionsprodukte 1, 2a und b wurden durch UV, 1H/13C-NMR und Massenspektren charakterisiert. Die spektroskopischen Daten von L-Discadenin zeigten dabei volle Übereinstimmung mit denen des Sporenkeimungsinhibitors aus Diciyostelium discouicum.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120905
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  • 173
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    Eine umkehrbare Gerüstumlagerung im trans- Erythrinan-Ringsystem, II. Neue trans- und 1(6→7)abeo-trans- Erythrinane (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3110-3125 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A Reversible Rearrangement of the trans-Erythrinane Ring System, II. New trans-and 1(6→7)abeo-trans-ErythrinanesThe scope of the reversible rearrangement 1⇌2 is assessed. 1 and its monosubstituted derivatives 5-9 yield the trans-dihydroxy-1(6→7)abeo- trans-erythrinane lactams 10-23 (derivatives of “diol-A*”). Compounds such as 3/4 and 24/25 are, however, not formed under the same conditions. Under certain conditions, the reaction can be accomplished in two steps, in either direction. The rearrangement step consists of a spontaneous 1,2-shift of four reaction centres.
    Notes: Der Gültigkeitsbereich der umkehrbaren Gerüstumlagerung 1⇌2 wird abgegrenzt. Aus 1 und seinen monosubstituierten Derivate 5-9 erhält man die trans-Diol-1 (6 → 7)abeo- trans-erythrinanlactame (Diol-A*-Derivate)10 - 23, während Verbindungen vom Typus 3/4 und 24/25 unter den angewandten Bedingungen nicht darstellbar sind. Unter bestimmten Bedingungen können die Reaktionen in beiden Richtungen auch in zwei Schritten durchgeführt werden. Im Umlagerungsschritt wechseln jeweils vier Partner unter 1,2-Verschiebung spontan ihre Plätze.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120909
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  • 174
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    Reaktionen mit Cyclopropenen, III. tert-Butylamino-substituierte Aromaten durch Photocyclisierung von N-tert-Butyl(arylvinyl)keteniminen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3166-3170 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions with Cyclopropenes, III. tert-Butylamino-Substitued Aromatic Compounds by Photocyclization of N-tert-Butyl(arylvinyl)ketene IminesN-tert-Butyl(arylvinyl)ketene imines 2a-g, obtained by ring-cleavage of the cyclopropenes 1a-g with tert-butyl isocyanide, cyclize on irradiation in a hexatriene-cyclohexadiene isomerisation with subsequent 1,7-hydrogen transfer to the tert-butylamino-substituted aromatic compounds 4a-f and 4g.
    Notes: Die durch Ringspaltung der Cyclopropene 1a-g mit tert-Butylisocyanid erhaltenen N-tert-Butyl-(arylvinyl)ketenimine 2a-g cyclisieren beim Bestrahlung in einer Hexatrien-Cyclohexadien-Isomerisierung mit anschließender 1,7-Wasserstoffverschiebung zu den tert-butylamino-substituierten Aromaten 4a-f und 4g.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120914
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  • 175
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    Bausteine von Oligosacchariden, XVII. Synthese von Trehalosamin, Mannotrehalosamin und verwandten α, α(1→1)-verknüpften Disacchariden (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3203-3213 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Building Units for Oligosaccharides, XVII. Synthesis of Trehalosamine, Mannotrehalosamine, and Related α,α(1→1)-Linked Disaccharides6-O-Acetyl-2-azido-3,4-di-O-benzyl-2-deoxy-β-D-glucopyranosyl chloride (1) reacts with 2,3,4,6-tetra-O-benzyl-α-D-glucopyranose (2) in the presence of silver perchlorate and sym-collidine with good stereoselectivity to give the α,α(1→1)-linked disaccharide 3. Deblocking of 3 by sodium in liquid ammonia affords α,α-trehalosamine 5. Correspondingly, the reaction of 1 with the manno-derivative 6 affords 8, which can be converted into α,α-mannotrehalosamine 9. Several other α,α(1→1)-linked disaccharides of the trehalosamine type containing additional azido groups have been synthesized. The α,α(1→1)-linked disaccharides 21 and 23 containing 2-azido-2-deoxy-α-D-galactopyranose could be prepared, too.
    Notes: 6-O-Acetyl-2-azido-3,4-di-O-benzyl-2-desoxy-β-D-glucopyranosylchlorid (1) reagiert mit 2,3,4,6-Tetra-O-benzyl-α-D-glucopyranose (2) bei Gegenwart von AgCIO4 und sym-Collidin in guter Stereoselektivität zum α,α(1→1)-verknüpften Disaccharid 3. Entblockierung von 3 mit Natrium in flüssigem Ammoniak liefert Trehalosamin 5. Entsprechend führt die Umsetzung von 1 mit dem manno-Derivat 6 zu 8, aus dem das Mannotrehalosamin 9 freigesetzt werden kann. Eine Reihe weiterer α,α(1→1)-verknüpfter Disaccharide vom Trehalosamin-Typ, die zusätzliche Azido-Gruppen enthalten, wurden synthetisiert. Auch α,α(1→1)-verknüpfte Disaccharide 21 und 23 mit 2-Azido-2-desoxy-α-D-galactopyranose-Einheiten lieβen sich darstellen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120917
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  • 176
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    Additionsreaktionen mit 2-Methoxyalkyl-Radikalen. Eine neue synthetische Methode zur Umwandlung von Alkenen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3759-3765 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Addition Reactions of 2-Methoxyalkyl Radicals. A New Synthetic Method of Alkene TransformationThe (2-methoxyalkyl)mercury chlorides 5 und 8 react with NaBH(OCH3)3 in the presence of electron deficient alkenes 6a-1 to form the products 7a-1 and 9a-1. The yields of this C-C-formation reaction depend on the structure of the alkenes and the organomercuric salts (Table 1). A radical chain is proposed for the formation of 7 and 9 which is a formal addition of substituted alkanes to the alkenes 6.
    Notes: Die Umsetzung der (2-Methoxyalkyl)quecksilberchloride 5 und 8 mit NaBH(OCH3)3 in Gegenwart der elektronenarmen Alkene 6a-1 liefert die Addukte 7a-1 und 9a-1. Die Ausbeuten dieser C - C-Verknüpfungsreaktion hängen von der Konstitution der Alkene und der Organoquecksilbersalze ab (s. Tab. 1). Für die Bildung der Produkte 7 und 9, die formal eine Anlagerung von substituierten Kohlenwasserstoffen an die Alkene 6 ist, wird ein Radikalkettenmechanismus vorgeschlagen.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791121203
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  • 177
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    Konjugation in makrocyclischen Bindungssystemen, XXIX. Synthese und Eigenschaften von Benzo[18]annulen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3907-3913 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Conjugation in Macrocyclic Systems, XXIX. Synthesis and Properties of Benzo [18]annuleneBenzo[18]annulene in which benzene and [18]annulene, as especially typical structures of benzenoid and non-benzenoid systems, are anellated was synthesized starting from 2 via 3, 4 (or 5), 6, and 7. Spectroscopic properties of 1 were studied under the aspect of the perturbation of the annulene conjugation by benzo-anellation. 1H NMR spectra show for 1 in comparison with 7, the immediate precursor without macrocyclic conjugation, a strong high-field shift for the internal protons and a down-field shift for the external protons, and thus prove the diatropicity of the [18]annulene system in 1.
    Notes: Benzo[18]annulen (1), in dem Benzol und [18] Annulen als besonders typische Strukturen benzoider und nicht-benzoider aromatischer Systeme anelliert sind, wurde ausgehend von 2 über 3,4 (oder 5), 6 und 7 synthetisiert. Spektroskopische Eigenschaften von 1 wurden unter dem Gesichtspunkt der Störung der Annulen-Konjugation durch die Benzo-Anellierung untersucht. 1H-NMR-Spektren zeigen für 1 im Vergleich zu 7. der direkten Vorstufe ohne makrocyclische Konjugation, eine starke Hochfeld-Verschiebung für die inneren Protonen und eine Tieffeld-Verschiebung für die äußeren Protonen; dies beweist die Diatropie des [18]Annulen-Systems in 1.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791121215
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  • 178
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    Notizen. Synthese und Eigenschaften von Lithium-tetrakis(trimethylsilyl)aluminat-Komplexen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3934-3938 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis and Properties of Lithium Tetrakis(trimethylsilyl)aluminate ComplexesChlorotrimethylsilane reacts with aluminium and lithium in ether in the presence of mercury to form lithium tetrakis(trimethylsilyl)aluminate, coordinated with diethyl ether, tetrahydrofurane, or dimethoxyethane. Unsolvated lithium tetrakis(trimethylsilyl)aluminate results by repeated sublimation of the ether adduct. The IR, Raman, and NMR spectra are discussed.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791121217
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  • 179
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    Metallcarbonyl-Synthesen, III. Eine ergiebige Hochdrucksynthese von Tetracarbonyl(η5-cyclopentadienyl)niob, (η5-C5H5)Nb(CO)4 (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 3942-3945 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Syntheses of Metalcarbonyls, III. A Productive High-Pressure Synthesis of Tetracarbonyl(η5-cyclopentadienyl)niobium, (η5-C5H5)Nb(CO)4Tetracarbonyl(η5-cyclopentadienyl)niobium (1), which could hitherto be prepared only in small amounts, can be synthesized with reproducible yields by reductive high-pressure carbonylation of (η5-C5H5)2NbCl2 (2) on a 5 - 20 g scale.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791121219
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    Darstellung substituierter Metalla-aziridine durch Reaktion von C5H5(CO)2M-Chelat-Komplexen (M=Mo, W) mit Nucleophilen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 2079-2086 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of Substituted Metalla-aziridines by the Reaction of C5H5(CO)2M-Chelate Complexes (M=Mo, W) With NucleophilesThe complexes [C5H5(CO)2MNN′]Cl (M=Mo W) 1a-e and 2a-c containing the five membered chelate rings MNN′ (NN′ =Schiff base derived from 2-pyridinecarbaldehyde and various amines) react with CH3Li, C6H5Li, and p-R′C6H4MgBr (R′ = H, CH3, OCH3, Cl) to from the neutral metalla-aziridines 3-6. 1H- und 13C-NMR spectra indicate a stereospecific course of the ring contraction.
    Notes: Die Komplexe [C5H5(CO)2MNN′]Cl (M=Mo, W) 1a-e und 2a-c mit fünfgliedrigem Chelatring MNN′ (NN′ =Schiffbase aus 2-Pyridincarbaldehyd und verschieden Aminen) reagieren mit CH3Li, C6H5Li und p-R′C6H4MgBr (R′ = H, CH3, OCH3, Cl) zu den neutralen Metalla-aziridines 3-6. 1H und 13C-NMR Spektren deuten auf einen stereospezifischen Ablauf der Ringverengung.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120618
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    1,6-Anhydrofuranosen, IX. Selektive Monotosylierung der 1,6-Anhydro-α-D-galactofuranose. Synthese und Bestimmung der Molekülstruktur der 1,6 :3,5-Dianhydro - α-D-gulofuranose (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 2068-2078 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1,6-Anhydrofuranoses, IX. Selective Monotosylation of 1,6-Anhydro-α-D-galactofuranose. Synthesis and Structure Determination of 1,6: 3,5-Dianhydro-α-D-gulofuranoseReaction of 1,6-anhydro-α-D-galactofuranose (1a) with 1.7 mol ρ-toluenesulfonyl chloride gives a mixture of all possible tosylates, the 3-0-derivative 1f with than 40% isolated yield predominating. Cyclization of 1f yields 1,6:3,5-dianhydro-α-D-gulofuranose (2a) with 2,5,7-trioxatricyclo[4.2.1.03.8]nonane skeleton. the structure of it being determined by X-ray crystallography and discussed in comparison to the equally determind structure of 1,6-anhydro-α-L-gulofuranose (3a).
    Notes: Umsetzung von 1,6-Anhydro-α-D-galactofuranose (1a) mit 1.7 mol ρ-Toluolsulfonylchlorid liefert ein Gemisch aller denkbaren Tosylate, in dem das 3-0-Derivat 1fmit über 40% isolierter Ausbeute überwiegt. Dieses läßt sich zur 1,6:3,5-Dianhydro-α-D-gulofuranose (2a) mit 2,5,7-Trioxatricyclo[4.2.1.03.8] nonan-Gerüst cyclisieren, deren Struktur wie die der 1,6-Anhydro-α-L-gulofuranose (3a) durch Röntgenstrukturanalyse bestimmt und diskutiert wird.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120617
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    Sterisch gehinderte zweiflügelige Propellermoleküle (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 138-147 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Sterically Hindered Two-blade Propeller MoleculesSubstituting bulky groups (comp. 5-9, 11, 12) in the one-atom bridge of the [6.1]metabenzenophane skeleton 18 greatly influence the molecular conformations as clearly shown by 1H NMR and UV spectroscopic comparisons with the open-chained analogues 15-17. Rotational hindrance and fixation of the ring inversion process is particularly marked with the exocyclic bornan-2-ylidene residue in 11. π-π-Interactions are also indicated by bathochromic shifts in the UV spectra.
    Notes: Durch Substitution des [6.1] Metabenzenophangerüsts 18 an der Einatom-Brücke mit sperrigen Resten (vgl. 5-9, 11, 12) werden die Molekülkonformationen stark beeinflußt, wie 1H-NMR und UV-spektroskopische Vergleiche mit den offenkettigen Modellen 15-17 zeigen. Die Rotationsbehinderung und Fixierung des Ringinversionsvorgangs ist bei dem exocyclischen Bornan-2-yliden-Rest in 11 deutlich ausgeprägt. Auch werden π-π-Wechselwirkungen aufgrund von bathochromen Verschiebungen in den UV-Spektren angenommen.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19791120114
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    Untersuchungen an Stoffwechselprodukten von Mikroorganismen, XVII. Neue Pigmente Vom Flexirubin-Typ aus Cytophaga spec. Stamm Samoa (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 196-208 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Investigations on Metabolites of Microorganisms, XVVI. New Pigments of the Flexirubin-type from Cytophaga spec. Strain SamoaThe gliding bacterium Cytophaga spec. strain Samoa produces a complex of pigments which consists of 8 substances. These have been shown to possess flexirubin-type structures 6a-h. some of these pigments (6a-d) contain chlorine at ring A. Their structures differ from each other and from flexirubin (1) by the lengths of alkyl substituents at ring B. In contrast to flexirubin no methyl or other alkyl group is found at ring A.
    Notes: Der von dem Gleitenden Bakterium Cytophaga spec. Stamm Samoa produzierte Farbstoffkomplex besteht aus 8 Pigmenten vom Flexirubin-Typ, deren Konstitutionen 6a-h aufgeklärt wurden, Sie unterscheiden sich untereinander und von Flexirubin (1) durch die Länge der Alkylsubstituenten am Ring B. Im Gegensatz zu Flexirubin trägt Ring A weder eine Methyl- noch eine andere Alkyl-Gruppe; 6a-d sind am Ring A chloriert.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19791120118
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  • 184
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    Donor/Akzeptor-substituierte aromatische Systeme, I. Dicarbonyl (η5 -cyclopentadienyl) (1,2,3-triphenylcyclo-propenyl)eisen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 218-233 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Donor/Acceptor Substituted Aromatic Systems, I. Dicarbonyl (η5 -cyclopentadienyl)(1,2,3-triphenylcyclopropenyl)ironDicarbonyl (η5 -cyclopentadienyl)(1,2,3-triphenylcyclopropenyl)iron (13), the structure of which has been determined by X-ray crystallography, is formed from triphenylcyclopropenylium tetra-fluoroborate or bromide and sodium dicarbonyl(cyclopentadienyl)ferrate. With bromine, iodine, tetrafluoroboric acid, trifluoroacetic acid, and triethyloxonium tetrafluoroborate 13 gives triphenylcyclopropenylium salts (12), with hydrogen halides 1,2-diphenylindene (23), with acyl chlorides in the presence of aluminium chloride 3-acyl-1,2-diphenylindenes (25), and with mercuric chlorides hexaphenylbicyclopropene 14. Irradiation of 13 leads to the (oxocyclobutenyl)iron complex 9e and triphenylcyclobutenone (28). Obviously, 13 does not display any properties of a cyclopropenyl anion.
    Notes: Dicarbonyl (η5 -cyclopentadienyl)1,2,3-triphenylcyclopropenyl)eisen (13), dessen Bindungsverhältnisse durch eine Röntgenstrukturanalyse gesichert wurden, entsteht aus Triphenylcyclo-propenylium-tetrafluoroborat oder -bromid und Natrium-dicarbonyl(cyclopentadienyl)ferrat. Mit Brom, Iod, Tetrafluoroborsäure, Trifluoressigsäure und Triethyloxonium-tetrafluoroborat entstehen aus 13 Triphenylcyclopropenylium-Salze (12), mit Halogenwasserstoffsäuren 1,2-Diphenylinden (23), mit Säurechloriden in Gegenwart von Aluminiumchlorid 3-Acyl-1,2-diphenylindene (25) und mit Quecksilberchlorid Hexaphenylbicyclopropen 14. Die UV-Bestrahlung von 13 ergibt einen (Oxocyclobutenyl)eisen-Komplex (9e) neben Triphenylcyclobutenon (28), Offensichtlich weist 13 keine Cyclopropenyl-Anion-Eigenschaften auf.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19791120120
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  • 185
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    Neue thermische Cycloadditionen eines Thieno[3,4-c]isothiazols an Alkine und Alkene (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 266-280 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: New Thermal Cycloaddition Reactions of a Thieno[3,4-c]isothiazole to Alkynes and AlkenesThe novel triphenylthieno[3,4-c]isothiazole 1 contains two masked 1,3-dipolar systems - a thiocarbonyl imine and a thiocarbonyl ylide; only the latter is capable of cycloaddition reactions as shown by theoretical considerations and experimental results. Thus, 1 reacts at the thiocarbonyl ylide site of the molecule with dimethyl acetylenedicarboxylate via a non-isolable primary adduct 2 to the benzisothiazole 3a (86%). In the same way, 1 combines with methyl propiolate to give the regioisomeric esters 3b, c in a ratio of 43:57. On the other hand, the reactions of 1 with alkenes proceed without sulfur elimination to form the isolable primary adducts of type 7. The corresponding reactions of 1 with dimethyl maleate, dimethyl fumarate, fumarodinitrile, or N-phenylmaleimide proceed with stereospecific formation of the tetrahydro-4,7-epithio-2,1-benzisothiazoles 7a - f, k, m (table 2). Furthermore, 1 reacts with methyl acrylate to produce the four stereo-and regioisomeric esters 7g-j. The constitutions of the adducts are in agreement with chemical reactions and transformations, their configurations are consistent with NMR data.
    Notes: Das neue Triphenylthieno[3,4-c]isothiazol 1 beinhaltet zwei maskierte 1,3-dipolare Systeme  -  ein Thiocarbonyl-imin und ein Thiocarbonyl-ylid; nur letzteres ist zur Cycloaddition befähigt, wie theoretische Betrachtungen und Experimente lehren. So reagiert 1 locospezifisch an der Thiocarbonyl-ylid-Molekülseite mit Acetylendicarbonsäure-dimethylester über ein nicht-isolierbares Primäraddukt 2 zum Benzisothiazol 3a (86%). In gleicher Weise vereinigt sich 1 mit Propiolsäure-methylester zu den regioisomeren Carbonestern 3b, c im 43:57-Verhältnis. Dagegen kommt es bei den Reaktionen von 1 mit Alkenen nicht zur Schwefel-Abspaltung, die Primäraddukte vom Typ 7 sind isolierbar. Die entsprechenden Umsetzungen von 1 mit Maleinsäure-dimethylester, Fumarsäure-dimethylester, Fumarodinitril bzw. N-Phenylmaleinimid verlaufen stereospezifisch zu den Tetrahydro-4,7-epithio-2,1-benzisothiazolen 7a - f,k,m (Tab. 2). Weiterhin vereinigt sich 1 mit Acrylsäure-methylester zu den vier stereo-und regioisomeren Estern 7g - j. Die Konstitutionen der Addukte sind mit chemischen Abbau-und Überführungsreaktionen, ihre Konfigurationen mit NMR- Daten in Einklang.
    Additional Material: 3 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19791120124
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  • 186
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    Radikalische Anlagerung von Thiophenol an Norbornadien (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 304-309 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Radical Addition of Thiophenole to NorbornadieneRadical addition of thiophenole to norbornadiene affords the 1:1 adducts 1, 2, 3 and 4 in a mixture that depends on the concentration of the starting material and on reaction temperature (table 1). Performing experiments between -40 and -20°C and using equations (d)-(f), it can be shown that the H-donation from thiophenole to 7 and 8 is lower in activation enthalpy by 4.3 and 1.6 kcal/mol, respectively than the norbornenyl-nortricyclyl radical rearrangement 7 ⇄ 8 (table 2). The nortricyclyl radical 8 is about 2.7 kcal/mol less stable than the norbornenyl radical 7.
    Notes: Radikalische Addition von Thiophenol an Norbornadien liefert die 1:1-Addukte 1, 2, 3 und 4 in Gemischen, die von der Konzentration der Reaktionspartner und der Reaktionstemperatur abhängen (s. Tab. 1). Beim Arbeiten zwischen -40 und -20°C läßt sich aus den Gln. (d)-(f) ermitteln, daß die H-Übertragung von Thiophenol auf7 bzw.8 mit 4.3 bzw. 1.6 kcal/mol niedrigeren Aktivierungsenthalpien abläuft als die Norbornenyl-Nortricyclyl-Radikalumlagerung 7 ⇄ 8 (s. Tab. 2). Das Nortricyclyl-Radikal 8 ist um etwa 2.7 kcal/moi instabiler als das Norbornenyl-Radikal 7.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19791120128
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  • 187
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    1-Alkenyl- und 1-Cycloalkenylphosphonium-Salze durch Selenenylierung von Phosphor-Yliden und anschließende Seleninsäure-Eliminierung (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 355-362 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of 1-Alkenyl- and 1-Cycloalkenylphosphonium Salts by Selenenylation of Phosphorus Ylides and Subsequent Seleninic Acid EliminationAlkylidenephosphoranes (phosphorus ylides) can be mono- or diselenenylated with phenylselenenyl bromide, dependent on the number of α-H-atoms in the starting phosphonium salt. Accordingly [1-(phenylseleno)alkyl]- and [1,1-bis(phenylseleno)alkyl]phosphonium salts 2a-e and 1, resp., are obtained. Oxidative elimination of the phenylseleno residue in 2a-e as phenylseleninic acid leads to 1-alkenylphosphonium salts 3a-e in high yields. Hydrolysis of cycloalkenylphosphonium salts 3c - e gives cycloalkenylphosphane oxides 4c-e. These can also be prepared by selenenylation of the corresponding cycloalkylphosphane oxides and subsequent PhSeO2H elimination. Some reactions and properties of the new compounds are examined.
    Notes: Alkylidenphosphorane (Phosphor-Ylide) können ein- bzw. zweifach, je nach der Zahl der α-H-Atome des Ausgangs-Phosphoniumsalzes, mit Phenylselenenylbromid selenenyliert werden. Dabei entstehen [1-(Phenylseleno)alkyl]- bzw. [1,1-Bis(phenylseleno)alkyl]triphenylphosphonium-Salze 2a - e bzw. 1. Oxidative Eliminierung der Phenylseleno-Gruppe von 2 als Phenylseleninsäure liefert in hohen Ausbeuten 1-Alkenyltriphenylphosphonium-Salze 3a-e. Hydrolyse der Cycloalkenylphosphonium-Salze 3c-c ergibt (1-Cycloalken-1-yl)phosphanoxide 4c-e. Diese können wiederum aus Cycloalkylphosphanoxiden durch Selenenylierung und nach-folgende PhSeO2H-Eliminierung hergestellt werden. Einige Eigenschaften und Reaktionen der neuen Verbindungen werden mitgeteilt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120131
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  • 188
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    Notizen. Darstellung und einige Reaktionen von cis, cis-2,4-Di-tert-butylmuconsäureanhydrid (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 389-391 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Preparation and Some Reactions of cis,cis-2,4-Di-tert-butylmuconic Anhydridecis,cis-2,4-Di-tert-butylmuconic anhydride (1) was prepared by the Baeyer-Villiger reaction from 3,5-di-tert-butyl-o-benzoquinone with monoperphthalic acid in 76% yield. It is relatively stable against water and reacts with aqueous sodium hydroxide to give 2,4-di-tert-butyl-2,5-dihydro-5-oxo-2-furanacetic acid (2), with methanol to form the corresponding ester 3 and with dry ammonia to yield the corresponding amide 4. All compounds were characterized spectroscopically.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120135
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  • 189
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    Eine einfache Synthese von Bis(trimethylsilyl)quecksilber (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 394-395 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A Simple Synthesis of Bis(trimethylsilyl)mercuryChlorotrimethylsilane reacts with mercury and aluminium in tetrahydrofuran with formation of bis(trimethylsilyl)mercury and other products. Bis(trimethylsilyl)mercury is easily isolated by sublimation from the reaction mixture.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120137
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  • 190
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    Synthese des (±)-„Isoalbens“ (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 397-407 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of (±)-“Isoalbene”In an attempt to synthesize the natural compound „albene“ it was shown that this material does not possess structure 1. Actually 1 is produced via the Diels-Alder adduct 10, followed by hydrogenation to 11 and Thorpe-Ziegler ring closure of the third carbocyclic ring by means of dinitrile 19. The resulting symmetrical ketone 3 is transformed into the thioenolether 21 with phenylmethanthiol. Desulfurization with Raney nickel yields 2.6-dimethyl-endo-tricyclo[5.2.1.02,6]dec-3-ene (1). which is not identical with natural „albene“.
    Notes: Bei dem Versuch einer Totalsynthese des Naturstoffs „Alben“ zeigte sich, daß diesem nicht die Strukturformel 1 zukommen kann. Die Darstellung von 1 erfolgte auf dem Wege über das Diels-Alder-Addukt 10, Hydrierung zu 11 und Schließen des dritten carbocyclischen Ringes mit Hilfe des Dinitrils 19 und Thorpe-Ziegler-Verfahrensweise. Das solcherart zugängliche symmetrische Keton 3 ließ sich mit Phenylmethanthiol in den Thioenolether 21 überführen. Entschwefelung mit Raney-Nickel ergab 2,6-Dimethyl-endo-tricyclo[5.2.1.0:2,6]dec-3-en (l), das mit natürlichem „Alben“ nicht übereinstimmte.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/cber.19791120202
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  • 191
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    Natürlich vorkommende Terpen-Derivate, 155. Neue Sesquiterpene mit anomalem Kohlenstoffgerüst aus der Tribus Mutisieae (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 427-434 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Naturally Occurring Terpene Derivatives, 155. New Sesquiterpenes with an Anomalous Carbon Skeleton from the Tribe MutisieaeThree species from the tribe Mutisieae afforded several new sesquiterpenes, their structures most probably being 1, 2 and 7-9, which have the hitherto unknown isocedrene carbon skeleton. Two further tetraesters probably have the structures 12a and 12b. The chemotaxonomical importance of this new type of sesquiterpenes has to be clarified by further investigations.
    Notes: Die Arten der Tribus Mutisieae ergeben mehrere neue Sesquiterpene, denen wahrscheinlich die Konstitutionen 1, 2 und 7-9 zukommen und die das bisher unbekannte Isocedren-Kohlenstoffgerüst besitzen. Zwei weiteren Tetraestern kommen wahrscheinlich die Konstitutionen 12a und 12b zu. Die chemotaxonomische Bedeutung dieses neuen Sesquiterpentyps muß durch weitere Untersuchungen geklärt werden.
    Additional Material: 2 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19791120205
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  • 192
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    Eine neue biomimetische Umwandlung von Chalcon-glycosiden in Isoflavon-glycoside (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 480-483 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A Novel Biomimetic Transformation of Chalcone Glycosides to Isoflavone GlycosidesAcetates of chalcone glucosides were oxidatively rearranged by thallium(III) nitrate in CH(OMe)3/, MeOH and the products cyclized with sodium methoxide to isoflavone glucosides. The pterocarpan medicarpin β-D-glucopyranoside (4) was prepared in an optically pure form.
    Notes: Acetate von Chalcon-glucosiden wurden mit Thallium(III)-nitrat in CH(OMe)3/MeOH oxidativ umgelagert und die Produkte mit Natriummethylat zu Isoflavon-glucosiden cyclisiert. Das Pterocarpan Medicarpin-β-D-glucopyranosid (4) wurde in optisch reiner Form hergestellt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120210
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  • 193
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    Ringöffnende Cycloadditionen, VI. Reaktionen von 5-Imino-Δ3-1,2,4-thiadiazolinen mit Heterocumulenen (Präparative Gesichtspunkte) (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 517-531 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ring Cleaving Cycloadditions, VI. Reaction of 5-Imino-Δ3-1,2,4-thiadiazolines with Heterocumulenes (Preparative Aspects)From imidoylthioureas 2 several 5-imino-Δ3-1,2,4-thiadiazolines were prepared as salts (3) and free bases (4) by means of dehydrogenating cyclization. The bases 4 added carbon disulfide and acyl isothiocyanates with cleavage of the original ring to give derivatives of 1,2,4-dithiazoles 5, 6, and added isocyanates, alkyl and aryl isothiocyanates, carbodiimides, and nitriles to form derivatives of 1,2,4-thiadiazoles 7-9, 11. All reaction products contain a benzamidino group as side chain. Their constitutions were proven spectroscopically. An X-ray analysis of 8b17) demonstrated anomal σ-bonds.
    Notes: Durch dehydrierenden Ringschluß wurde aus den Imidoylthioharnstoffen 2 eine Anzahl 5-Imino-Δ 3-1,2,4-thiadiazoline als Salze 3 und freie Basen 4 hergestellt. Letztere addierten Kohlenstoffdisulfid und Acyl-isothiocyanate unter Öffnung des ursprünglichen Ringes zu den 1,2,4-Dithiazol-Derivaten 5 und 6; Isocyanate, Alkyl- und Aryl-isothiocyanate, Carbodiimide und Nitrile zu den 1,2,4-Thiadiazol-Derivaten 7-9, 11. Allen Reaktionsprodukten ist eine Benzamidino-Seitenkette gemeinsam. Die Konstitution der Verbindungen wurde spektroskopisch ermittelt, auf ihre anomalen Bindungsverhältnisse (σ-Delokalisation) wurde anhand einer Röntgenstrukturanalyse von 8b17) eingegangen.
    Additional Material: 4 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19791120215
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    Übergangsmetall-Carbin-Komplexe, XLVI. Silylcarben- und Silylcarbin-Komplexe von Chrom und Wolfram (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 2177-2189 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Transition Metal Carbyne Complexes, XLVI. Silylcarbene and Silylcarbyne Complexes of Chromium and TungstenHexacarbonyltungsten reacts with LiSi(CH3)n(C6H5)3-n and subsequently methyl fluorosulfonate to yield the pentacarbonyl[methoxy(silyl)carbene]tungsten complexes (CO)5WC(OCH3)Si(CH3)n-(C6H5)3-n (1 b: n = 1, 1 c: n = 2, 1 d: n = 3). The aminolysis of 1 b and c with dimethylamine leads to the pentacarbonyl[dimethylamino(silyl)carbene]tungsten complexes(CO)5 WC[N(CH3)2]-Si(CH3)n(C6H5)3-n (2b: n = 1, 2c: n = 2). The reaction of (CO)5WC(OCH3)Si(C6H5)3 (la),1b, c, and (CO)5CrC(OCH3)Si(C6H5)3(l e) with Ga2C16 or Al2Br6 at low temperature produces the thermolabile trans-halogenotetracarbonyl(silylcarbyne)chromium and -tungsten compunds X(CO)4MCSi(CH3)n(C6H5)3-n (3, 4a-c, e). The halogen exchange reaction of 4 a-c with lithium iodide readily forms trans-iodotetracarbonyl(silylcarbyne)tungsten complexes I(CO)4WCSi(CH3)n-(C6H5)3-n (5a-c). The reaction of 4a with sodium pentacarbonylrhenate yields tran-tetracarbonyl-(pentacarbonylrhenio)(triphenylsilylcarbyne)tungsten (6). Sodium cyclopentadienide reacts with 4 a and b to form dicarbonyl (π-cyclopentadienyl)silylcarbyne)tungsten complexes π-C5H5(CO)2-WCSi(CH3)n C6H5)3-n (7 a: b), while dicarbonyl (η5-indenly)(triphenylsilylcarbyne)tungsten (8) is produced from 4 a and lithium indenide. Properties and spectra of the partly thermolabile compounds are reported.
    Notes: Hexacarbonylwolfram reagiert mit LiSi (CH3)n(C6H5)3-n und nachfolgend Fluorsulfonsäuremethylester zu den Pentacarbonyl[methoxy(silyl)carben]wolfram-Komplexen (CO)5WC(OCH3)-Si(CH3)n(C6H5)3-n (1 b: n = 1, 1 c: n = 2, 1 d: n = 3). Die Aminolyse von 1b und c mit Dimethylamin ergibt die Pentacarbonyl[dimethylamino(silyl)carben]wolfram-Komplexe(CO)5WC[N(CH3)2]Si(CH3)n(C6H5)3-n (2b: n = 1, 2c: n = 2). Aus (CO)5 WC(OCH3)Si(C6H5)3(1a), 1b, c und (CO)5CrC(OCH3)Si(C6H5)3 (l e) lassen sich bei tiefen Temperaturen mit Ga2Cl6 order Al2Br6 thermolabile trans-Halogenotetracarbonyl(silylcarbin)chrom- und -wolfram-Verbindungen X(CO)4 MCSi(CH3) n(C6H5)3-n (3; 4a-c, e) darstellen. Die Halogen-Austauschreaktion mit Lithiumiodid erweist sich bei 4a-c als einfacher Zugang Zu trans-Iodotetracarbonyl-(silylcarbin)wolfram-Komplexen I(CO)4 WCSi(CH3)n(C6H5)3-n (5a-c). Durch Umsetzung von 4a mit Natriumpentacarbonylrhenat wird trans-Tetracarbonyl(pentacarbonylrhenio)(triphenyl-silylcarbin)wolfram (6) erhalten. Cyclopentadienylnatrium reagiert mit 4a und b zu den Dicarbonyl (π-cyclopentadienyl)(silycarbin)wolfram-Komplexen π-C5H5(CO)2WCSi(CH3)n(C6H5)3-n(7 a;b), Indenyllithium mit 4a zu Dicarbonyl (η5-indenyl)(triphenyisilylcarbin)wolfram (8). Eigenschaften und Spektren werden beschrieben.
    Additional Material: 4 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19791120625
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  • 195
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    Diels-Alder-Reaktionen von 2,3-Bis(trimethylsilyloxy)-1,3-dienen (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 2209-2219 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Diels-Alder Reactions of 2,3-Bis(trimethylsilyloxy)1,3-dienesDiels-Alder reactions of 2,3-bis(trimethylsilyloxy)-1,3-dienes 2, 3 and 4 with a number of dienophiles afford the desired cycloadducts 7-11, 13-16, and 20-23 containing a 1,2-bis(trimethylsilyloxy)-alkene function which can be transformed in a variety of ways. For example, they react with bromine under mild conditions to form 1,2-diketones. The method is complementary to Scharf's cycloadditions of dichlorovinylene carbonate.
    Notes: Diels-Alder-Reaktionen von 2,3-Bis (trimethylsilyloxy)-1,3-dienen 2, 3 und 4 mit einer Reihe von Dienophilen liefern die gewünschten Cycloaddukte 7-11, 13-16 und 20-23, die eine abwandelbare 1,2-Bis(trimethylsilyloxy) ethylen-Funktion enthalten. Sie lassen sich z. B. unter milden Bedingungen mit Brom glatt in 1,2-Diketoverbindungen überführen. Die Methode ist komplementär zu den von Scharf beschriebenen Cycloadditionen mit Dichlorvinylencarbonat.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120628
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  • 196
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    Darstellung und Umlagerung von Succinimidosulfonium-Salzen aus Sulfiden mit verminderter Nucleophilie (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 2231-2242 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Formation and Rearrangement of Succinimidosulfonium Salts from Sulfides with Lower Nucleophilic CharacterThe presence of antimony pentachloride is necessary for the formation of succinimidosulfonium salts 4 from N-chlorosuccinimide (2) and the sulfides 1b-g. The arylmethyl salts 4b-d and the methyl(methoxycarbonylemethyl) salt 4e react with tertiary amines to give the imidates 7b-e. With the allylsulfonium salts 4f, g only the products 6f, g of an [1.2]-shift may be isolated. The additional formation of an imidate 7f from 4f is shown by low temperature 1H NMR spectroscopy.
    Notes: Zur Darstellung der Succinimidosulfonium-Salze 4 aus N-Chlorsuccinimid (2) und den Sulfiden 1b-g ist die Zugabe von Antimonpentachlorid notwendig. Die Arylmethyl-Salze 4b-d und das Methyl(methoxycarbonylmethyl)-Salz 4e führen mit tert. Aminen zu den Imidaten 7b-e. Bei den Allylsulfonium-Salzen 4f, g sind nur die Produkte 6f, g aus einer [1.2]-Umlagerung isolierbar. Durch Tieftemperatur-1H-NMR-Spektroskopie läßt sich die zusätzliche Entstehung eines Imidats 7f aus 4f nachweisen.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120630
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  • 197
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    Neue μ-Hydroxo-Übergangsmetallkomplexe, I. Darstellung und Struktur des trans-Diaqua-di-μ-hydroxo-bis[(1,4,7-triazacyclononan)cobalt(III)]-Kations; Kinetik und Mechanismus seiner Bildung (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 2220-2230 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Novel μ-Hydroxo-Transition Metal Complexes, I. Preparation and Crystal Structure of the trans-Diaqua-di-μ-hydroxo-bis[(1,4,7-triazacyclononane)cobalt(III)]Cation; Kinetics and Mechanism of its FormationThe binuclear tri-μ-hydroxo-bis[(1,4,7-triazacyclononane)cobalt(III)] cation (1) is prepared. In acidic solutions 1 forms the trans-diaqua-μ-hydroxo-bis[(1,4,7-triazacyclononane)cobalt(III)] cation (2), the structure of which has been established by single crystal X-ray diffraction. The equilibration kinetics of the first hydroxo-bridge cleavage of the triply-bridged complex 1 have been studied. A mechanism is proposed involving cis-trans isomerization of 2 as the rate determining step. The mechanism is consistent with all (including previously published) experimental data for the OH-bridge cleavage processes of tri-μ-hydroxo-bis[aminecobalt(III)] complexes.
    Notes: Das zweikernige Tri-μ-hydroxo-bis[(1,4,7-triazacyclononan)cobalt(III)]-Kation (1) wird dargestellt. In saurer Lösung entsteht daraus das trans-Diaqua-di-μ-hydroxo-bis[(1,4,7-triazacyclononan)cobalt(III)]-Kation (2), dessen Struktur röntgenographisch bestimmt wurde. Die Kinetik der Gleichgewichtseinstellung der Spaltung der ersten OH-Brücke von 1 wurde gemessen. Es wird ein Mechanismus vorgeschlagen. Bei dem die cis-trans-Isomerisierung von 2 den geschwindigkeitsbestimmenden Schritt darstellt, und der alle(auch frühere) experimentelle Daten der OH-Brückenspaltung sowie die Bildung von Tri-μ-hydroxo-bis[amincobalt(III)]-Komplexen widerspruchsfrei deutet.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120629
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  • 198
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    Synthesen von Gallenfarbstoffen, VIII. Totalsynthese des racem. Phycoerythrobilin-dimethylesters (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 2243-2255 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses of Bile Pigments, VIII. Total Synthesis of Racemic Phycoerythrobilin Dimethyl EsterDesulfurization of the dithioacetals 3d and 9c on deactivated Raney nickel yielded 4-methyl-3-vinyl-3-pyrrolin-2-one (3e) and methyl 5′-tert-butoxycarbonyl-[4-vinyl]isoneobilirubinate (11a), respectively. The latter compound was transformed into the corresponding 5′-formyl derivative 11c which reacted with the already known 3,4-dihydro-5(1H)-pyrromethenone 10 to yield a mixture of two diastereomeric bile pigments, racem. 12a racem. 12b. After separation of the two components by preparative thin-layer chromatography, one of them, namely racem. 12b, proved to be identical with phycoerythrobilin dimethyl ester which is obtained from R-phycoerythrin by treatment with boiling methanol.
    Notes: Durch Entschwefelung der Dithioacetale 3d und 9c an desaktiviertem Raney-Nickel wurden 4-Methyl-3-vinyl-3-pyrrolin-2-on (3e) bzw. 5′-tert-Butoxycarbonyl-[4-vinyl]isoneobilirubinsäuremethylester (11a) synthetisiert. Letzterer wurde in das entsprechende 5′-Formyl-Derivat 11c übergeführt, dessen Kondensation mit dem bekannten 3,4-Dihydro-5(1H)-pyrromethenon 10 ein Gemisch aus zwei diastereomeren Gallenfarbstoffen, racem. 12a und racem. 12b, lieferte, die durch präparative Schichtchromatographie getrennt werden konnten. racem. 12b erwies sich als identisch mit Phycoerythrobilin-dimethylester, der durch Behandlung von R-Phycoerythrin mit siedendem Methanol erhalten wird.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120631
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  • 199
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    γ-Lactone aus α, β-ungesättigten Ketonen durch P—O-Olefinierung (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 2256-2277 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: γ-Lactones from α, β-Unsaturated Ketones by P—O OlefinationThe enones 2-5, 12, 14, 16-19 react with the phosphonate 1b in moderate to good yields to the E,Z-esters 6-9, 13, 15, 20-23. The γ, δ double bond of Z-8 was epoxidized to Z-31, which was hydrolyzed with acid to the butenolide 34. 34, and all the other γ-lactones 32, 33, 41, 44 are prepared in much better yields by P-O olefination of the epoxy ketones 26-28, 38, 42 to the E,Z-esters 29-31, 39, 43 followed by hydrolysis of the Z-esters. The E-esters 30, 31, 39 are hydrolyzed to the trans-diols 35, 36, and 40.
    Notes: Die Enone 2-5, 12, 14, 16-19 reagieren mit dem Phosphonat 1b in mäßigen bis guten Ausbeuten zu den E,Z-Estern 6-9, 13, 15, 20-23. Aus Z-8 wird durch Epoxidierung der γ,δ-Doppelbindung Z-31 und daraus nach saurer Hydrolyse das Butenolid 34 erhalten. 34 und alle weiteren γ-Lactone 32, 33, 41, 44 sind in erheblich besseren Ausbeuten durch P—O-Olefinierung der Epoxyketone 26-28, 38, 42 zu den E,Z-Estern 29-31, 39, 43 und Hydrolysieren der Z-Ester darstellbar, während die E-Ester 30, 31, 39 die trans-Diole 35, 36 und 40 liefern.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120632
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  • 200
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    Umsetzung des Chlordimethylphosphans mit Trimethylphosphan, Monomethylphosphan und Phosphan (1979)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 112 (1979), S. 2278-2281 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Chlorodimethylphosphane with Trimethylphosphane, Monomethylphosphane, and PhosphaneCompleting a previous investigation2), this paper gives evidence that dialkylchlorophosphanes generally react with tertiary and secondary phosphanes to yield penta- and tetraalkyldiphosphonium chlorides ([P2R5]+Cl-, [P2R4H]+Cl-), whereas primary phosphanes give polymer or cyclic phosphanes (PR)n and dialkylphosphonium chlorides [R2PH2]+Cl- Phosphane, PH3, is converted into polymer (PH)x.
    Notes: Eine frühere Untersuchung2) fortsetzend konnten wir am Beispiel der Methylverbindungen bestätigen, daß Dialkylchlorphosphane mit tertiären und sekundären Phosphanen unter Bildung von Penta- und Tetraalkyldiphosphonium-chloriden ([P2R5H]+Cl- [P2R4H]+Cl-) reagieren, während primäre Phosphane polymere oder cyclische Phosphane (PR)n und Dialkylphosphonium-chloride [R2PH2]+Cl- ergeben. Phosphan, PH3, wird in polymeres Phosphan (PH)x umgewandelt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19791120633
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