abstract |
A process for producing exo-methylenepenam compounds of general formula (2), wherein R1 represents a hydrogen atom, an amino group or a protected amino group; R2 represents a hydrogen atom, a halogen atom or the like; and R3 represents a hydrogen atom or a carboxyl-protective group, characterized by reducing a cephem compound of general formula (1), wherein R?1, R2 and R3¿ are each as defined above; and X represents a halogen atom or the like, with at least an equimolar amount of a metal having a standard oxidation reduction potential of not higher than -0.3 (V/SCE) and 0.0001 to 30 mol, per mole of the compound, of a metal compound having a standard oxidation-reduction potential higher than that of the metal. |