Industrial transformations of penicillins and cephalosporins

Abstract
A survey is presented of transformations of penicillin G into penicillin and cephalosporin derivatives. Amongst other things the issues discussed are the conversion of penicillin G into 6‐aminopenicillanic acid (6‐APA) and some semi‐synthetic penicillins, ring expansion of the penicillin nucleus giving the cephalosporin nucleus and subsequently 7‐aminodeacetoxycephalosporanic acid (7‐ADCA), and the synthesis of various 3′‐substituted cephalosporin derivatives, including the tert‐butyl ester of 3‐(bromomethyl)‐7‐(phenylacetamido)‐3‐cephem 1‐oxide (3‐BMC®).