Application of erythro-2-amino-1,2-diphenylethanol as a highly efficient chiral auxiliary. Highly stereoselective Staudinger-type β-lactam synthesis using a 2-chloro-1-methylpyridinium salt as the dehydrating agent

Abstract

The Staudinger-type reaction of carboxylic acids with imines, using a 2-chloro-1-methylpyridinium salt as the dehydrating reagent, proceeded smoothly under mild conditions to afford the desired β-lactams in high yields with excellent cis-selectivity. This reaction was successfully applied to the asymmetric synthesis of β-lactams using a chiral glycine derivative as the acid component, which was prepared from an artificial chiral auxiliary, (1S,2R)-2-amino-1,2-diphenylethanol. The corresponding β-lactams were obtained in high yields with excellent stereoselectivity.