Synthesis and antibacterial activity of 1-substituted-methyl carbapenems

The synthesis of the 1 alpha- and the 1 beta-substituted (fluoro, cyano, hydroxy and acetoxy)-methyl carbapenems having a 2-(1,3,4-thiadiazol-2-yl)thiomethyl side chain are described, and their in vitro antibacterial activities are compared with the corresponding 1 beta-methyl carbapenems together with imipenem. The synthesis and antibacterial activity of the 1 beta-substituted (fluoro and cyano)-methyl carbapenems having 2-(1-alkyl-4-pyridinio)thiomethyl side chains are also described.