Amino-acids and peptides. Part I. Esterification of the carboxy-group of penicillins and cephalosporins by hydrazone oxidation

Abstract

A new and efficient process for esterifying N-blocked amino-acids and peptides with readily removed protecting groups is described. Illustrations are given with particular reference to S-oxides of penam acids. The new process comprises oxidation of a hydrazone in an organic or aqueous organic solvent in the presence of the N-blocked amino-acid or peptide, and with a trace of iodine as catalyst.