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  • 1980-1984  (19)
  • 1965-1969
  • 1935-1939
  • 1890-1899
  • 1830-1839
  • 1980  (19)
  • Inorganic Chemistry  (13)
  • Cell & Developmental Biology  (3)
  • General Chemistry  (2)
  • Visual system
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Years
  • 1980-1984  (19)
  • 1965-1969
  • 1935-1939
  • 1890-1899
  • 1830-1839
Year
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    Direkte ortho-Metallierung von Benzylalkoholen Eine neuartige Herstellung von ortho-substituierten Benzylalkoholen (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 1304-1319 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Direct ortho-Metalation of Benzyl Alcohols. A Novel Method of Preparing ortho-Substituted Benzyl AlcoholsBenzyl alcohol and other phenylcarbinols (8a - 11a), including α-tetralol (12a), are doubly deprotonated by excess n-butyllithium/TMEDA in pentane to give lithium ortho-lithioalkoxides (2, 8b - 12b). Alkylations (→ 3a - d, table 1), reactions with heteroelectrophiles (→ 3e - k, table 2) and with carbonyl compounds (→ 6, 13 - 17, tables 3 and 4), as well as subsequent reactions of the primary adducts (→ phthalanes 7, table 3) furnish a large variety of ortho-substituted benzyl alcohol derivatives. The scope and limitations of the dilithioorganyls (sections B and C), their mode of formation (section A), and attempts to doubly metalate 2-phenylethanol [section D, equation (4)] are discussed.
    Notes: Benzylalkohol und andere Phenylcarbinole (8a - 11a), einschließlich α-Tetralol (12a), werden von überschüssigem Butyllithium/TMEDA in Pentan zu Lithium-ortho-lithioalkoholaten (2, 8b - 12b) doppelt deprotoniert. Alkylierungen (→ 3a - d, Tab. 1), Umsetzungen mit Heteroelektrophilen (→ 3e - k, Tab. 2) und Carbonylverbindungen (→ 6, 13 - 17, Tab. 3 und 4) sowie Folgereaktionen der Primäraddukte (→ Phthalane 7, Tab. 3) liefern eine Vielzahl verschiedenartigster, ortho-substituierter Benzylalkoholderivate. Die Anwendungsgrenzen der Dianionderivate (Abschnitte B und C), ihr Bildungsmechanismus (Abschnitt A) und Versuche zur Doppelmetallierung von 2-Phenylethanol [Abschnitt D, Gl. (4)] werden diskutiert.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130410
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  • 2
    Electronic Resource
    Electronic Resource
    Doppelt metalliertes Methanol. Alkohol-d1- und -d3 -Reagenzien (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 1290-1303 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Doubly Metalated Methanol.  -  Alcohol d1-and d3-ReagentsThe nucleophilic counterpart of the electrophilic hydroxymethylating protonated formaldehyde B is the hypothetical tautomer A, R=H, of methoxide. Experiments are described in which the generation of doubly metalated methanol C (= formaldehyde ketyl dianion) and its use as methanol d1-reagent are attempted. Treatment of stannylated methanol 1 with two equivalents of butyllithium furnishes a pentane-soluble reagent which hydroxymethylates electrophilic centers in moderate yields (umpolung of the formaldehyde a1-reactivity), see eq. (1) and table 3. Attempted isolation, 1H- and 13C-NMR measurements, and careful product analysis of the reaction with benzaldehyde (scheme 1 and table 2) support the view that the new reagent is actually not free lithium lithio-methoxide (2) but a tin derivative, see for instance 9 in eq. (2).  -  The O-silylated derivative 18 (=A, R=SiMe3) is likewise generated by Sn-Li-transmetallation, but cannot be trapped externally by electrophiles due to rapid Wittig rearrangement (→ 19 → 20). The readily accessible dilithio derivatives 21a and 23a can be employed as direct propanol and allyl alcohol d3-reagents, respectively.
    Notes: Das nucleophile Pendant zum elektrophilen Hydroxymethylierungsmittel B, dem protonierten Formaldehyd, ist das fiktive Methanolat-Tautomere A, R=H. Es werden Versuche zur Erzeugung des doppelt metallierten Methanols C (= Formaldehyd-Ketyldianion-Derivat) und dessen Verwendung als Methanol-d1-Reagenz beschrieben. Durch Umsetzung des stannylierten Methanols 1 mit zwei Äquivalenten Butyllithium erhält man ein pentanlösliches Reagenz, welches elektrophile Zentren in mäßigen Ausbeuten hydroxymethyliert (Umpolung der Formaldehydreaktivität), Gl. (1) und Tab. 3. Isolierungsversuche, 1H- und 13C-NMR-Messungen sowie sorgfältige Produktanalyse der Reaktion mit Benzaldehyd (Schema 1 und Tab. 2) stützen die Hypothese, daß das erzeugte Reagenz nicht das freie Lithium-lithiomethanolat (2), sondern ein Sn-Derivat, z. B. 9 in Gl. (2) sein dürfte.  -  Das ebenfalls durch Sn/Li-Transmetallierung erzeugte O-Silylderivat 18 [=A, R=Si(CH3)3] läßt sich wegen zu schneller Wittig-Umlagerung (→ 19 → 20) nicht extern mit Elektrophilen abfangen, während die leicht zugänglichen Dilithiumderivate 21a und 23a als direkte Propanol- bzw. Allylalkohol-d3-Reagenzien fungieren.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130409
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  • 3
    Electronic Resource
    Electronic Resource
    Direkte Hydroxymethylierung zu verzweigten Zuckern mit einem Hydroxymethyl-d1-Reagenz (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 2055-2061 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Direct Hydroxymethylation to Branched-chain Sugars by means of a Hydroxymethyl-d1 ReagentBlocked ketoses react with the dianion 2 directly to hydroxymethylation products. Butylation products have been found as by-products. The procedure in which the yields are limited can be used favourably in special cases.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130545
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  • 4
    Electronic Resource
    Electronic Resource
    The distribution of monoamine oxidase and biogenic monoamines in the central nervous system of spiders (Arachnida: Araneida) (1980)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 164 (1980), S. 69-81 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The distribution and activity patterns of monoamine oxidase and monoaminergic (formaldehyde-induced) fluorescence in the central nervous system of web-building and hunting spiders have been studied using histochemical methods. Enzyme activity occurred in the neuronal perikarya and in varying intensity in the structures of the neuropile mass, but only when dopamine, adrenaline, and noradrenaline were used as substrates. The optic centres of the spider brain normally exhibited relatively strong enzyme reactions when compared with the staining intensity of the rest of the nervous system.The neuronal cell bodies contained numerous granules of yellow-green fluorescence. Monoaminergic fluorescence of the neuropile was generally a weak green. The optic mases of the hunting spiders, the anterior bridge, several commissures of the ventral cord, and the neural lamellae showed a slightly higher fluorescence intensity and single fluorescing granules.The results obtained indicate the presence of catecholamines in the spider nervous system.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051640106
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  • 5
    Electronic Resource
    Electronic Resource
    The visual system of the guitar fish (Rhinobatos productus) (1980)
    Springer
    Cell & tissue research 206 (1980), S. 243-250 
    Details
    ISSN: 1432-0878
    Keywords: Guitar fish ; Elasmobranchs ; Visual system ; Degeneration study
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The retinal projections in adult and juvenile guitar fish (Rhinobatos productus) were determined with the aid of the Nauta-Fink-Heimer techniques. The visual system was found to be more extensive and more differentiated than in any other elasmobranch studied to date. Massive projections exist to the dorsal and ventral thalamus, tectum and pretectum, in addition to the usual weak contributions to the hypothalamus and the ventral mesencephalic tegmentum. The projection to the lateral tectum is significantly less distinct than that to the medial part of this structure, suggesting that the ventral visual field has a smaller input, perhaps due to the fact that this visual field is normally aimed at the body of this flat fish.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00232768
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  • 6
    Electronic Resource
    Electronic Resource
    Quantitative cell changes and vascularisation in the early corpus luteum of the pregnant rat (1980)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 197 (1980), S. 369-374 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Early corpora lutea (CL) of the rat were histologically examined on Day 1, 2, 4, and 6 of gestation. Measurements were taken of total volume and of the number of luteal and endothelial cells in one CL of both ovaries of five rats at each stage examined. CL volume increased over the 6 days from --0.76 to 1.39μl and peripheral plasma progesterone levels from 8.1 to 33.2 ng/ml. The number of luteal cells per CL (range 303,000 to 37,000) did not significantly change, and there was no evidence of mitosis or death amongst these cells. Luteal cell volume increased from 1.74 to 3.49 pl and nuclear volume from 0.25 to 0.38 pl, the former being the major cause of CL growth. The CL appeared to be richly vascularized, even on Day 1, and the number of endothelial cells per CL (range 289,000 to 354,000) remained relatively constant over the period examined.It was concluded that the number of luteal cells per CL is determined prior to or around ovulation in the rat and that subsequent growth of the CL is due to hypertrophy and not hyperplasia.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1091970311
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  • 7
    Electronic Resource
    Electronic Resource
    Synthesen mit 2,6-Didesoxyglyosylhalogeniden. Aufbau des B - A-Disaccharid-Glycosids aus Chromomycin A3 (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 3058-3066 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthetic Application of 2,6-Dideoxyglycosyl Halides. Construction of the B - A Disaccharide Glycoside in Chromomycin A3By photolytic deoxygenation of the diacetoxy-3,4-O-isopropylidene galacto compound 2 the 2,6-dideoxy derivative 3 is obtained. Mild acidolysis gives 4, the acetylation of which yields the monoacetates 5 and 6, and in addition the diacetate 7. Methylation of 6 using diazomethane under boron trifluoride catalysis leads to the 4-O-methyl compound 9, and with bromotrimethylsilane the 2,6-dideoxy glycosyl bromide 8 is obtained. Correspondingly, 7 gives the bromide 10 which, according to a varied glycoside synthesis procedure is condensed with the monohydroxy compound 5 to yield the α, 1 → 3-linked disaccharide 11. By partial deacetylation the selective synthesis of 12 is achieved. The corresponding condensation of 5 and 8 allows the preparation of the disaccharide 13 which is subsequently transferred to the methyl glycoside 14 of the B - A disaccharide unit of chromomycin A3. The NMR spectral data of 14 and the disaccharide unit B - A in chromomycin A3 are consistently in agreement.
    Notes: Aus dem Diacetat der 3,4-O-Isopropyliden-galacto-Verbindung 2 wird durch photolytische Desoxygenierung 3 gewonnen, dessen milde Acidolyse zu 4 führt. Die Acetylierung gibt die Monoacetate 5 und 6 sowie das Diacetat 7. Durch Methylierung von 6 mit Diazomethan unter Bortrifluorid-Katalyse wird das 4-O-Methyl-Derivat 9 gewonnen, das mit Bromtrimethylsilan glatt zum 2,6-Didesoxyglycosylbromid 8 reagiert. Aus 7 ist entsprechend das Bromid 10 erhältlich, das mit der Monohydroxy-Verbindung 5 nach einer variierten Glycosidsynthesemethode zur Bildung des α, 1→3-verknüpften Disaccharids 11 führt. 11 kann selektiv zu 12 partiell deacetyliert werden. Entsprechend wird aus 8 und 5 das Disaccharid-Derivat 13 dargestellt und zum Methylglycosid der B-A-Disaccharideinheit 14 aus Chromomycin A3 umgesetzt. Die NMR-spektroskopischen Daten von 14 stehen mit denen für den B - A-Disaccharidblock aus Chromomycin A3 vollauf in Übereinstimmung.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130920
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  • 8
    Electronic Resource
    Electronic Resource
    Darstellungen von Disaccharidglycosiden des B - A-Typs in Chromomycin A3 nach dem N-Iodsuccinimid-Verfahren (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 3067-3074 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation of Disaccharide Glycosides of the B - A Type in Chromomycin A3 by Application of the N-Iodosuccinimide ProcedureReduction of the galacto derivative 1 to 2 followed by a selective acetolysis yields 3. The double reaction step for the preparation of the glycal surprisingly gives 5, in which the isopropylidene group is maintained. By N-iodosuccinimide reaction with the hydroxy compound 4 exclusively the β,1 → 3-linked disaccharide 7 is obtained, and subsequently reduced to the tetradeoxy compound 8. In contrast to this, under similar conditions by reaction of diacetylfucal 9 with 4 only the α,1 → 3-linked disaccharide 10 is obtained, which can be reduced to the tetradeoxy derivative 11. Starting with triacetylgalactal several steps lead to the hydroxyl component 16, by reaction of which with 9 the α,1 → 3-linked disaccharide 17 is obtained, similarly. By subsequent reduction the synthesis of the derivative 18 of the B - A type of chromomycin A3 is achieved.
    Notes: Das galacto-Derivat 1 wird glatt zu 2 reduziert und erfährt eine selektive Acetolyse zu 3. Bei dessen Umsetzung zum Glycal bleibt die Isopropylidengruppe überraschend erhalten, so daß 5 resultiert. Die N-Iodsuccinimid-Reaktion mit der Hydroxylkomponente 4 führt ausschließlich zur Bildung des β, 1→3-verknüpften Disaccharids 7, das zum Tetradesoxydisaccharid 8 reduziert werden kann. Dagegen wird aus dem Diacetylfucal 9 und 4 unter den gleichen Bedingungen nur das α, 1→3-gebundene Disaccharid 10 erhalten, das reduktiv zum Tetradesoxydisaccharid-Derivat 11 umgesetzt wird. Das aus Triacetylgalactal in einigen Schritten darstellbare 3-Hydroxy-Derivat 16 reagiert mit 9 ebenfalls nur zum α, 1→3-verknüpften Disaccharid 17, aus dem das Derivat 18 vom B - A-Typ in Chromomycin A3 gewonnen wird.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130921
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  • 9
    Electronic Resource
    Electronic Resource
    Di- und Polyaminozucker, XXIII. Eliminierungsvorgänge bei der Synthese der 2,3-Diamino-2,3-didesoxy-D-glucose (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 3089-3093 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Di- and Polyamino Sugars, XXIII. Elimination Reactions Accompanying the Synthesis of 2,3-Diamino-2,3-dideoxy-D-glucoseBy-products of the synthesis of 2,3-diamino-2,3-dideoxy-D-glucose were found to be hex-2- and -3-enopyranosides (4, 5). Structure proofs by spectroscopy were corroborated by hydroboration and direct elimination reactions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130924
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  • 10
    Electronic Resource
    Electronic Resource
    Synthesen mit Iod- und Bromtrimethylsilan in der Saccharidchemie (1980)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 3075-3085 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthetic Application of Iodo- and Bromotrimethylsilane in Saccharide ChemistryIn simple model compounds an enhanced rate is observed in the reaction of iodotrimethylsilane with acetates and with cyclohexyl esters. Primary and secondary acetoxy-substituted saccharides show an exclusive formation of glycosyl iodides. Accordingly, pentaacetyl hexopyranoses and iodotrimethylsilane give in high yields the corresponding glycosyl iodides. Methyl glycosides can be transformed similarly, and with lactose octaacetate the formation of α-heptaacetyllactosyl iodide proceeds smoothly without rupture of the interglycosidic linkage. This procedure is particularly valuable for the synthesis of 2-deoxyglycosyl iodides. Corresponding reactions with bromotrimethylsilane are achieved in a similar way. By opening of epoxides with iodotrimethylsilane in the case of sterically fixed saccharide oxiranes the trans-diaxial, and with more flexible derivatives predominantly the trans-diequatorial iodohydrines are obtained.
    Notes: Bei Umsetzungen einfacher Modellverbindungen mit Iodtrimethylsilan zeigen sich höhere Reaktionsraten bei Acetaten und bei Cyclohexylestern. Bei Einsatz primärer und sekundärer Saccharid-Acetoxyderivate wird dagegen die ausschließliche Bildung der Glycosyliodide festgestellt. Pentaacetylhexopyranosen reagieren mit Iodtrimethylsilan in hohen Ausbeuten zu den entsprechenden Tetraacetylglycosyliodiden. Auch Methylglycoside lassen sich umsetzen; beim Lactoseoctaacetat zeigt sich, daß unter α-Heptaacetyllactosyliodid-Bildung die interglycosidische Bindung intakt bleibt. Besonders wertvoll ist das Verfahren zur Gewinnung der 2 Desoxyglycosyliodide. Entsprechende Umsetzungen mit Bromtrimethylsilan werden erfolgreich vorgenommen. Epoxidöffnungen mit Iodtrimethylsilan verlaufen bei sterischer Fixierung des Saccharid-Oxirans zu den trans-diaxialen bzw. bei sterisch beweglichen Derivaten überwiegend zu den trans-diäquatorialen Iodhydrinen.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19801130922
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