CHEMISTRY OF AZIRIDINE CARBOXYLIC-ACIDS .7. SYNTHESIS OF ETHYL (2R,3S)-N-BOC-3-VINYLAZIRIDINE-2-CARBOXYLATES AND (2R,3S)-N-BENZYL-3-VINYLAZIRIDINE-2-CARBOXYLATES - NEW POTENTIAL BUILDING-BLOCKS FOR ENANTIOMERICALLY PURE UNSATURATED AMINO-ACIDS

Enantiomerically pure cis- and trans-1H-aziridine-carboxylic acid deri vatives 2a, b and 3a, b have been prepared by asymmetric Michael-type addition of ammonia to chiral acrylates 1a, b with high syn selectivit y. The title compounds were obtained from the diols 8a, b by Corey-Win ter olefination.