Efficient stereoselective route to β-lactams and their application to the stereoselective synthesis of a key intermediate for carbapenem antibiotic (+)-PS-51

Abstract

A combination of a stereoselective addition of benzenethiol to α,β-unsaturated carboxylic acid derivatives and a subsequent substitution reaction of the corresponding sulfonium group with O-alkylhydroxamate anion has provided a new practical and stereoselective method for the construction of 3,4-disubstituted cis- and trans-β-lactams. A successful application was demonstrated by the formal asymmetric synthesis of (+)-PS-5.