Colin W. Greengrass

γ-Lactam analogues of carbapenicillanic acids

Abstract The syntheses and biological activities of the γ-lactam analogues ( endo -25), ( exo -25) and (26) of carbapenicillanic acids are described. The strategy employed for the synthesis of 26 effected construction of a γ-lactam onto a preformed azetidine, followed by direct amination of the lactam enolate (20) with diphenylphosphinoyl-hydroxylamine. X-ray crystallographic studies demonstrated that the analogues bore a strong morphological resemblance to carbapenicillanic acids; however, they were shown to be devoid of antibacterial and beta-lactamase inhibitory activity.1

New routes to tetracycline analogues: an intramolecular Diels–Alder approach

A new and short approach to tetracycline analogues is presented using an intromolecular Diels–Alder approach.