Patent ID: 6043356
Filing Date: 2000-03-28
Classification: C07D

Abstract:
A process for preparing an exo-methylenepenam compound of formula (5) ##STR15## wherein R.sup.1 is selected from the group consisting of hydrogen, amino and protected amino; R.sup.2 is selected from the group consisting of hydrogen, halogen, C.sub.1-4 alkoxy, formyl, acetyl, propionyl, butyryl, isobutyryl and C.sub.1-4 alkyl which is substituted by hydroxyl or protected hydroxyl; and R.sup.3 is hydrogen or a carboxylic acid protecting group, the process comprising:reducing a .beta.-lactam halide compound of formula (2) ##STR16## wherein R.sup.1, R.sup.2 and R.sup.3 are as defined above, R.sup.4 is aryl or substituted aryl; X is halogen; Y is selected from the group consisting of a halogen atom, a substituted or unsubstituted lower alkylsulfonyloxy group, a substituted or unsubstituted aromatic sulfonyloxy group, a substituted or unsubstituted halogenated lower alkyl sulfonyloxy group, a substituted or unsubstituted lower alkylphosphoryloxy group and a substituted or unsubstituted aromatic phosphoryloxy group; and n is 0 to 2,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 halide 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 halide compound, to obtain the exo-methylenepenam compound of formula (5).