Cephemderivat og fremgangsmåde til fremstilling deraf

Described herein is a cephem derivative represented by the general formula:wherein n stands for 1 or 2, Y stands for CH or nitrogen atom, R, represents a lower hydrocarbon group or a carboxyl-substituted, a carbamoyl-substituted, or a cyclopropyl-substituted lower alkyl group, and R2 denotes hydroxyl group, a lower alkyl group, a hydroxy-substituted lower alkyl group, or carbamoyl group. The derivative is useful as antibacterial composition. Also described herein are process for the production of the derivative, antibacterial composition, intermediate of the derivative and process for the production thereof.