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  • 1
    Electronic Resource
    Electronic Resource
    Synthese von Zuckerestern der Lysergsäure und 9,10-Dihydrolysergsäure (1979)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 321 (1979), S. 171-174 
    Details
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis of Sugar Esters of Lysergic Acid and 9, 10-Dihydrolysergic Acid
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/prac.19793210126
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  • 2
    Electronic Resource
    Electronic Resource
    The Inversion of the Amino Group in Vinylamine, a Flexible Model TreatmentA preliminary account of this work was given at the meeting of the Swiss Chemical Society in Geneva, October 9, 1976. (1978)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 61 (1978), S. 1418-1426 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Flexible model results for the —NH2 inversion in vinylamine are compared with microwave data published by Lovas et al. [3]. The information available on the spacing of inversion levels is found to be sufficient to rule out a planar equilibrium structure. Shifts of rotational constants upon excitation of the inversion are calculated for two predicted paths of motion derived from PRDDO geometry optimization results obtained by MiiIler & Brown [2]. Partial geometry optimization yields a path inconsistent with experiment but the path obtained from complete optimization produces shifts in excellent agreement with the observed shifts. A potential energy function compatible with experimental data on spacing of inversion levels is calculated from the observed inertia defects. The inversion angle at equilibrium is slightly smaller than the angle predicted from PRDDO calculations, and the barrier to inversion, ΔV = 1.08 ± 0.07 kcal/mol, is approximately half the PRDDO value.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19780610426
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  • 3
    Electronic Resource
    Electronic Resource
    Imin-Enamin-Tautomerie, V1) Lösungsmittel- und Temperaturabhängigkeit der Thioimidsäureester/Keten-S,N-acetal-Tautomerie (1975)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1975 (1975), S. 36-40 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Imine-Enamine Tautomerism, V1). - Solvent- and Temperature-dependence of Thioimidoate/Ketene S,N-Acetal TautomerismI n solution N-aryl(thioimidoates) 2a exist predominantly in the ketene S,N-acetal form. The tautomeric equilibrium depends on the solvent and temperature. The quantity of the chelate ketene S,N-acetal 2b decreases with increasing polarity and ability of the solvent to form intermolecular hydrogen bonds. - The equilibrium constants and the values of the thermo-dynamic parameters ΔG, ΔH und Δ,S of the compound 2 (Rl = 4-Br, R* = CH3) have been determined in two solvents of different polarity by IH-NMR measurements. An increase in temperature and consequent decrease in entropy leads to destabilization of the ketene S,N-acetal in the tautomerism 2a ⇌ 2b.
    Notes: Die N-Aryl(thioimidsäure)ester 2a liegen in Lösung überwiegend in der tautomeren Keten-S,N-acetalform 2b vor. Das Tautomeriegleichgewicht ist lösungsmittel- und temperatur-abhängig. Mit zunehmender Polarität und zunehmender Befähigung des Lösungsmittels zur Ausbildung intermolekularer Wasserstoffbrücken sinkt der Gehalt des chelatisierten Keten-S,N-acetals 2b. - In zwei Lösungsmitteln unterschiedlicher Polarität wurden für die Verbindung 2 (R1 = 4-Br, R2 = CH3) 1H-NMR-spektroskopisch die Gleichgewichtskonstanten und die Werte der thermodynamischen Größen ΔG, ΔH und Δ,S bestimmt. Steigende Temperatur führt wegen der Entropieabnahme bei der Tautomerisierung 2a ⇌ 2b ebenfalls zur Destabilisierung des Keten-S,N-acetals.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197519750104
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  • 4
    Electronic Resource
    Electronic Resource
    Über die katalytische Umwandlung von Olefinen, VI. Mischoligomerisation von Butadien mit Bicyclo[2.2.1]hept-2-enenZum Gedenken an Professor K. Ziegler. (1975)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1975 (1975), S. 743-751 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Catalytic Conversion of Olefins, VI. - Co-oligomerization of Butadiene with Bicyclo[2.2.l]hept-2-enesIn contrast to 2-butene and cyclopentene, bicyclo[2.2.l]hept-2-ene and its derivatives react as strained olefins with butadiene to give substituted cis,trans-l,5-cyclodecadienes in yields of up to 90% in the presence of nickel-ligand catalysts. The ten-membered rings rearrange thermally to the corresponding cis-l,2-divinylcyclohexane derivatives. Ni-C-addition to the double bond of bicyclo[2.2.l]hept-2-ene occurs on the exo side.
    Notes: Im Gegensatz zu 2-Buten und Cyclopenten können Bicyclo[2.2.l]hept-2-en und seine Derivate als gespannte Olefine an Nickel-Ligand-Katalysatoren mit je zwei Molekülen Butadien in Ausbeuten bis zu 90% zu substituierten cis,trans-l,5-Cyclodecadienen reagieren. Die substituierten Zehnringe lagern sich thermisch in die entsprechenden cis-1.2-Divinylcyclohexanderivate um. Die Ni -C-Addition an die Doppelbindung des Bicyclo[2.2.1]hept-2-ensystems erfolgt von der exo-Seite.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197519750416
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  • 5
    Electronic Resource
    Electronic Resource
    Synthese von (-)(1S, 7S)-exo-Brevicomin aus (+)-(2R, 3R)-Weinsäure-diethylester (1977)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1977 (1977), S. 732-736 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of (-1S, 7S)-exo-Brevicomine starting from (+)-(2R, 3R)-Diethyl TartrateThe sex attractant 4 of western pine beetle Dendroctonus brevicomis has been synthesised in high yield in optically active form starting from (+)-(2R, 3R)-diethyl tartrate by coupling dithiane 5c with the optically active bromide 2d.
    Notes: Der Sexuallockstoff 4 des Borkenkäfers Dendroctonus brevicomis wird in guter Ausbeute in optisch aktiver Form ausgehend von (+)-(2R, 3R)-Weinsäure-diethylester über die Kupplung des Dithianderivates 5c mit dem optisch aktiven Bromid 2d synthetisiert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197719770503
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  • 6
    Electronic Resource
    Electronic Resource
    Imin-Enamin-Tautomerie, IV1) Untersuchungen zur Thioimidsäureester/Keten-S,N-acetal-Tautomerie (1975)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1975 (1975), S. 19-35 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Imine-Enamine Tautomerism, IV 1). - Investigation of Thioimidoate/Ketene S,N-AcetalAlkylation of thioanilides gives the thioimidoates 1a, which are in tautomeric equilibrium with ketene S,N-acetals 1b if suitable substituents are present. Diethyl [(arylimino)(methylthio)- methyl]malonates {methyl N-aryl-diethoxycarbonyl(thioacetimidoates)} are examined in order to show the influence of substituents on nitrogen, and for diethyl [(phenylimino)(benzylthio)-methyl]malonates {benzyl N-phenyl-diethoxycarbonyl(thioacetimidoates)} in order to illustrate the influence of sulfur-bonded substituents. - The results are discussed in connection with previously reported results for imine-enamine tautomerism. Together with further examples an attempt is made to deduce general rules for the description of imine-enamine tautomeric systems.
    Notes: Durch Alkylierung von Thioaniliden entstehen die Thioimidsäureester 1a, die bei geeigneter Substitution mit den Keten-S,N-acetalen 1b in einem Tautomeriegleichgewicht stehen. Am Beispiel der [(Arylimino)(methylthio)methyl]malonsäure-diäthylester IN-Aryl-diäthoxy-carbonyl(thioacetimidsäure)-methylester} wird der Einfluß des Substituenten am Stickstoffatom, am Beispiel der [(Phenylimino)(benzylthio)methyl]malonsäure-diäthylester {N-Phenyl-diäthoxycarbonyl(thioacetimidsäure)-benzylester} der Einfluß des an das Schwefelatom gebundenen Substituenten untersucht. - Die Ergebnisse werden im Zusammenhang mit früheren Ergebnissen zur Imin-Enamin-Tautomerie diskutiert, wobei der Versuch unternommen wird, unter Einbeziehung weiterer Beispiele allgemeine Regeln zur Beschreibung imin-enamin-tautomerer Systeme aufzustellen.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197519750103
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  • 7
    Electronic Resource
    Electronic Resource
    Dihydropyridine, III. Synthese von 2-Aminodihydropyridinen durch Michael-AdditionTeil eines Vortrages vor der Fachgruppe “Medizinische Chemie” der GDCh am 29 März 1974 in München. Herrn Prof. O. Bayer mit den besten Wünschen zum 75. Geburtstag gewidmet. (1977)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1977 (1977), S. 1895-1908 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dihydropyridines, III. - Synthesis of 2-Aminodihydropyridines via Michael AdditionMichael addition of amidinoacetic esters 4 to alkylidene- or aralkylideneacetoacetic esters 1 is followed by ring closure to give novel 2-amino-1,4-dihydropyridine-3,5-dicarboxylates 10. 2-Amino-1,4-dihydropyridine-3-carboxylates 20 are obtained by addition of 4 to α,β-un-saturated ketones 17. Reaction of 3-amino-3-dialkylaminoacrylic esters 25 with 1 leads to 2-dialkylamino-3,4-dihydropyridine-3,5-dicarboxylates 27. Condensation of aldehydes 21, 1,3-cyclohexanedione and 4 yields 2-amino-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylates 23.
    Notes: Die Michael-Addition der Amidinoessigsäureester 4 an Alkylidene- oder Aralkylidenacetessigsäureester 1 führt unter Ringschluß zu 2-Amino-1,4-dihydropyridin-3,5-dicarbonsäure-ester 10. An α, β-ungesättigte Ketoverbindungen 17 wird 4 zu den 1,4-Dihydropyridin-3-carbonsäureestern 20 addiert. 3-Amino-3-dialkylaminoacrylsäureester 25 liefern mit 1 unter analogen Bedingungen die 2-Dialkylamino-3,4-dihydropyridine 27. Die Aldehyde 21, 1,3-Cyclohexandion und 4 kondensieren zu den teilhydrierten 2-Amino-5-oxochinolin-3-carbon-säureestern 23.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197719771111
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  • 8
    Electronic Resource
    Electronic Resource
    Über die Biosynthese der Mutterkornalkaloide, VI. Über den Einbau von [4'-(E)-13C]4-(3-Methyl-2-butenyl)tryptophan in Clavinalkaloide und Lysergsäure (1978)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1978 (1978), S. 813-817 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Incorporation of [4'-(E)-13C]4-(3-Methyl-2-butenyl)tryptophan into Clavine Alkaloids and Lysergic AcidThe 13C-enriched C-atom of the 4'(E)-methyl groups of 4-(3-methyl-2-butenyl)tryptophan (3) appears during the biosynthesis at the C-methyl group of chanoclavine (4) and at C-17 of agroclavine (5), elymoclavien (6) and lysergic acid (7).
    Notes: Das 13C-angereicherte C-Atom der 4'-(E)-Methylgruppe im 4-(3-Methyl-2-butenyl)tryptophan (3) erscheint bei der Biosynthese in der C-Methylgruppe des Chanoclavins (4) und im C-17 von Agroclavin (5), Elymoclavin (6) und Lysergsäure (7).
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197819780516
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  • 9
    Electronic Resource
    Electronic Resource
    Dihydropyridine, II. Synthese von 1,4-Dihydropyridinen mit Brückenkopf-N-AtomTeil eines Vortrages vor der Fachgruppe “Medizinische Chemie” der GDCh am 17. Sept. 1976 in Münster. Herrn Prof. O. Bayer mit den besten Wünschen zum 75. Geburtstag gewidmet. (1977)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1977 (1977), S. 1888-1894 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dihydropyridines, II - Synthesis of 1,4-Dihydropyridines with Bridgehead NitrogenMichael addition of enaminocarbonyl compounds 9 to alkylidene or aralkylideneacetoacetic esters 6 is followed by ring closure to novel 1,4-dihydropyridines 5 with bridgehead nitrogen. This modified Hantzsch pyridine synthesis also permits preparation of bridged dihydropyridines 10 with a 5-keto function by condensation of aldehydes, 1,3-cyclohexanedione and 9. Analogous bridged dihydropyridines 13 and 14 with 3- or 3,5-keto function, respectively, are obtained by use of octahydroquinolone 11 as enaminocarbonyl component.
    Notes: Die Michael-Addition der N-verbrückten Enaminocarbonylverbindungen 9 an die Alkyliden-oder Aralkylidenacetessigsäureester 6 führt in einer modifizierten Hantzsch-Pyridinsyhthese zu 1,4-Dihydropyridinen 5 mit Brückenkopf-N-Atom. Analoge verbrückte 1,4-Dihydro-pyridine 10 mit einer Ketofunktion werden durch Kondensation von Aldehyden, 1,3-Cyclohexandion und 9 erhalten. Wird anstelle von 9 Octahydrochinolon 11 als Enaminocarbonylkomponente verwendet. so entstehen die verbrückten 1,4-Dihydropyridine 13 und 14 mit Ketofunktionen in 3- bzw. 3,5-Stellung.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197719771110
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  • 10
    Electronic Resource
    Electronic Resource
    Dihydropyridine, IV. Kondensation von Aldehyden mit EndiaminocarbonylverbindungenTeil eines Vortrages vor der Fachgruppe „Medizinische Chemie“ der GDCh am 29. März 1974 in München. (1978)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1978 (1978), S. 1476-1482 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Dihydropyridines, IV.  -  Condensation of Aldehydes with Enediaminocarbonyl CompoundsReaction of aldehydes 1 with double molar quantities of amidinoacetic esters 5 leads to the 2,6-diaminodihydropyridine-3,5-dicarboxylates 8. 2-Amino-6-dialkylamino-4,5-dihydropyridines 12 are obtained by condensation of 1 with 3-amino-3-dialkylaminoacrylic esters 11. Pyridones 17 with bridgehead nitrogen are formed by condensation of 1 with bridged enediaminocarbonyl compounds 15.
    Notes: Die Kondensation von Aldehyden 1 mit Amidinoessigsäureestern 5 im Molverhältnis 1:2 führt zu 2,6-Diaminodihydropyridin-3,5-dicarbonsäureestern 8. 3-Amino-3-dialkylaminoacrylsäureester 11 liefern mit 1 unter analogen Bedingungen die 2-Amino-6-dialkylamino-4,5-dihydropyridine 12. Dihydropyridone 17 mit Brückenkopf-N-Atom werden durch Kondensation von 1 mit den N,N′-verbrückten Endiaminocarbonsäureestern 15 erhalten.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197819780912
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