From Penicillin to Penem and Carbapenem. VII. : Synthesis and Antibacterial Activity of Penem Derivatives

The azetidinone derivative (6), which has an (R)-hydroxyethyl substituent at the C-3 position, was prepared efficiently from 6-aminopenicillanic acid. From the dibromo seco derivative (10), compounds of the same type (16 and 17), but in dl-form, were obtained. Compounds 6 and 16 were reacted with various thiocarboxylic acids to obtain the penem derivatives (23a-n).The minimum inhibitory concentration values of these penems against various microorganisms were, determined, and the structure-activity relationship is discussed.