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  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 2635-2639 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cumulated Ylides, XVI A Method for the Exchange of the OH Group in Free Carboxylic Acids by the Ylide FunctionCarboxylic acids 5 react with triphenyl[(phenylimino)ethenylidene]phosphorane (4) via the intermediate 6 with formation of the phosphoranes 7, which rearrange by heating in an intramolecular acyl migration to ylides 10. By heating of 10 in the presence of an alcohol 13 the acyl ylides 11 and urethanes 14 are formed. The reaction sequence allows the replacement of the OH group in carboxylic acids by the ylide function.
    Notes: Carbonsäuren 5 reagieren mit Triphenyl[(phenylimino)ethenyliden]phosphoran (4) unter Durchlaufen der Zwischenstufe 6 zu den Phosphoranen 7, die sich beim Erwärmen durch intramolekulare Acylwanderung in Ylide 10 umlagern. Beim Erhitzen von 10 in Gegenwart von Alkoholen 13 bilden sich die Acylylide 11 und Urethane 14. Die Reaktionsfolge gestattet es somit, in freien Carbonsäuren 5 die OH-Gruppe durch die Ylidfunktion zu ersetzen.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cumulated Ylides, XVII Synthesis of Cyclic Compounds from Triphenyl[(phenylimino)ethenylidene]phosphorane and Oxocarboxylic Acids - A Novel Method for AnellationBy entropically supported intramolecular Wittig reaction from α-keto carboxylic acids 23 with triphenyl[(phenylimino)ethenylidene]phosphorane (1) N-phenylmaleinisoimides 26 and -imides 29 are formed. The compounds 26 can be rearranged into 29 with a catalytic amount of sodium azide. - From γ-keto carboxylic acids 30 3-substituted 2-cyclopenten-1-ones 37 can be derived via the 3,6-dioxo-2-(triphenylphosphoranylidene)alkananilides 33. Analogously, 3-substituted 2-cyclohexen-1-ones 49 are formed from δ-keto carboxylic acids 46. o-Acylbenzoic acids 38, in the case R = H, are converted with 1 into the benzazepinedione derivative 44, and in the case R ≠ H into 3-substituted 1-oxo-1H-indene-2-carboxanilides 45. - Starting from oxo carboxylic acids, possessing the carbonyl function in a ring, five- and six-membered rings can be anellated in a simple way.
    Notes: Durch entropisch unterstützte intramolekulare Wittig-Reaktion entstehen bei der Umsetzung von α-Ketocarbonsäuren 23 mit Triphenyl[(phenylimino)ethenyliden]phosphoran (1) N-Phenylmaleinisoimide 26 und -imide 29. Die Verbindungen 26 lassen sich mit katalytischen Mengen Natriumazid in 29 umlagern. - Aus γ-Ketosäuren 30 lassen sich über die 3,6-Dioxo-2-(triphenyl-phosphoranyliden)alkananilide 33 3-substituierte 2-Cyclopenten-1-one 37 gewinnen. Analog entstehen aus δ-Ketosäuren 46 3-substituierte 2-Cyclohexen-1-one 49. o-Acylbenzoesäuren 38 lassen sich für R = H mit 1 in das Benzazepindion-Derivat 44 und für R ≠ H in 3-substituierte 1-Oxo-1H-inden-2-carboxanilide 45 überführen. - Ausgehend von Oxocarbonsäuren, die ihre Carbonylfunktion in einem Ring tragen, lassen sich in einfacher Weise 5- und 6-Ringe anellieren.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 98 (1986), S. 1007-1008 
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 25 (1986), S. 994-996 
    ISSN: 0570-0833
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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