Novel synthesis of 6,6-dibromo-2′-Z-chloromethyl and 2′-Z-bromomethyl anhydropenicllins from 6,6-dibromo 2β-(chloromethyl) and 2β-(bromomethyl)-2α-methyl-penam-3α-carboxylic acid via anhydropenicillin rearrangement

Abstract

We describe the preparation of isomerically pure 2′-Z-chloromethyl and 2′-Z-bromomethyl anhydropenicillins 2a and 2b, from 6,6-dibromo 2β-(chloromethyl) and 2β-(bromomethyl)-2α-methyl-penam-3α-carboxylic acid through the Wolfe rearrangement of anhydropenicillins.