PROCESS FOR PRODUCING EXO-METHYLENEPENAM COMPOUNDS

摘要

A process for preparing an exo-methylenepenam compound represented by the formula (2) wherein cephem compound represented by the formula (1) is reduced with a metal having a standard oxidation-reduction potential of up to -0.3 (V/SCE) in an amount of at least one mole per mole of the cephem compound and with a metal compound having a higher standard oxidation reduction potential than the metal in an amount of 0.0001 to 10 moles per mole of the cephem compound to obtain the exo-methylenepenam compound wherein R<1> is a hydrogen atom, amino or protected amino, R<2> is a hydrogen atom, halogen atom, etc. R<3> is a hydrogen atom or carboxylic acid protective group, X is a halogen atom, etc. wherein R<1>, R<2> and R<3> are as defined above.d