ISSN:
0009-2940
Keywords:
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Description / Table of Contents:
α-Amino Acids as Nucleophilic Acyl Equivalents, II. Synthesis of γ-Diketones by means of Oxazolin-5-onesOxazolin-5-ones 1, easily obtainable from α-amino acids, undergo base catalyzed addition of acylacetylenes to give 4-(3-oxopropenyl)-derivatives 2, which are cleaved on warming with oxalic acid dihydrate in acetic acid to yield γ-diketones 3. Starting from 4-alkylideneoxazolin-5-ones 7 4 1-branched oxazolinones 8 may be obtained via addition of lithium phenylthio(alkyl)cuprates. Despite of their high sterical hindrance the oxazolinones 8 are converted into α,α-disubstituted γ-diketones 10 as described for 1. The stereochemistry of the base catalyzed addition of benzoylacetylene to 1b has been investigated.
Notes:
Die aus α-Aminosäuren leicht Oxazolin-5-one, 1. addieren basenkatalysiert Acylacetylene zu 4-(3-Oxopropenyl)-Derivaten 2, die sich durch Erwärmen mit Oxalsäure-dihydrat in Essigsäure zu den γ-Diketonen 3 spalten lassen. Ausgehend von 4-Alkylidenoxazolin-5-onen 7 können durch 1,4-Addition von Lithium-phenylthio(alkyl)cupraten 4 1 -verzweigte Oxazolinone 8 erhalten werden, die trotz großer sterischer Hinderung auf analoge Weise in α, α-dialkylverzweigte γ-Diketone 10 überführbar sind. Die Stereochemie der basenkatalysierten Addition von Benzoyllacetylen an 1b wird untersucht.
Additional Material:
9 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19791120919
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