Improved Procedure for Conversion of Penicillin V Into Monocyclic β-Lactams

Abstract

Improved procedures for the preparation of the Kamiya compound (3 R,4R)-4-(benzothiazol-2′-yldithio)-3-phenoxyacetamidoazetidin-2-0 (6) from penicillin V (1) are described. A novel feature is ozonolysis, near room temperature, in aqueous methanol in the presence of pyridine or a trace of manganese dioxide.