Synthesis and antibacterial activity of some novel 6-methyl- and 6-propenyl-substituted carbapenems

The synthesis and antibacterial activity of a number of 6-methyl- and 6-propenyl-substituted carbapenems is described. The 6-(hydroxymethyl)- and 6-(aminomethyl)carbapenems possessed more potent antibacterial activity in vitro than their respective 6-(1'(R)-hydroxyethyl) or 6-(1'(R)-aminoethyl) counterparts. However, because of reduced stability, the 6-(aminomethyl)carbapenem was found to be inactive in vivo. All 6-hydroxypropenyl or 6-aminopropenyl derivatives that were prepared were less active than their respective 6-heteroethyl-substituted analogues.