Synthesis of Optically Active α-Methylene β-Lactams through Lipase-Catalyzed Kinetic Resolution

Abstract

A convenient method for the preparation of the hitherto unknown chiral α-methylene β-lactam derivatives 5a,b is reported. The optically active α-methylene β-lactams 5a−c, and their corresponding amino acids 6a−c have been readily made available through lipase-catalyzed kinetic resolution in high enantiomeric purity (up to 99% ee). The N-substituted β-lactam derivatives 4a,b and 10 are not accepted by the lipases and were prepared in optically active form by chemical transformation.