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DOI: 10.1055/s-1992-21545
Optically Active Oxazolidinones as Michael Donors: Synthesis of Novel Enantiopure α,β-Diamino Acids and 2-Substituted 1-Aminocyclopropane Carboxylic Acids1
Publikationsverlauf
Publikationsdatum:
08. März 2002 (online)

Optically active 2′-substituted methyl 2-azido-2-[1-(2-oxo-4, 5-diphenyloxazolidin-3-yl)cyclopropyl]acetates 5-R can be made from methyl 2-[1-(2-oxo-4,5-diphenyloxazolidin-3-yl)cyclopropyl]acetates 4-R y highly diastereoselective electrophilic azidations. Azidoesters of type 5-R can be deprotected by hydrogenolysis and saponified with 2 N sodium hydroxide to give 2′ -substituted 2-amino-2-(1-aminocyclopropyl)acetic acids 7-R. When treated with lithium methoxide, followed by acidic and by basic work-up, compounds 5-R yield 2-[1-(2-oxo-4, 5-diphenyloxazolidin-3-yl)cyclopropyl]-2-oxoacetic acids 9-R. These, upon treatment with lithium hydroxide and hydrogen peroxide, followed by catalytic hydrogenation, lead to different 2-substituted 1-aminocyclopropanecarboxylic acids 11-R in good yields.