Substituted penicillanic acid 1,1-dioxides as β-lactam inhibitors: studies on 6-benzylidene- and hydroxybenzylpenam sulphones

Abstract

The preparation of the two epimers of (6R)-6-(α-hydroxybenzyl)penicillanic acid and the corresponding sulphones is described. The absolute configuration about the hydroxy substituted carbon atom has been elucidated by an investigation of the dehydration to the corresponding 6-benzylidenepenicillanic acids, (αR,6R)-6-(α-Hydroxybenzyl)penicillanic acid 1,1-dioxide (15) is a powerful inhibitor of class C β-lactamases such as that isolated from Pseudomonas aeruginosa. Some comments are made on the possible mode of action of these types of inhibitor.