Synthesis and in-vitro activity of new 1beta-methylcarbapenem derivatives as antibacterial agents.

The synthesis of a new series of 1beta-methylcarbapenems having pyrrolidine and piperidine moieties is described. Their in-vitro antibacterial activities against both Gram-positive and Gram-negative bacteria were tested and the effect of substituents on the pyrrolidine ring was investigated. A particular compound III b having an oxime-pyrrolidine moiety showed the most potent antibacterial activity.