Process for preparing carbapenem compounds

摘要

Novel and effective process for preparing a carbapenem compound of the formula (III): wherein R1 and R2 are each H or lower alkyl, R3 is lower alkyl, R4 is protecting group, L is substituted or unsubstituted arylsulfonyloxy, lower alkanesulfonyloxy, halogeno-lower alkanesulfonyloxy, di-lower alkylphosphoryloxy, etc., and X is H or protected hydroxy, which comprises reacting beta -lactam compound (I) with acetic acid ester derivative (II), in the presence of base, followed by treating the product with active esterifying agent for hydroxy group, said compound (III) being useful as intermediate for 1 beta -alkylcarbapenem compound having antibacterial activity.