7-oxo-4-thia-1-azabicyclo3,2,0heptane derivatives

Abstract From the Canadian patent

Compounds of the formula IIa IIb and IIc, wherein, R represents a carboxyl esterifying group removable by hydrolysis, photolysis, reduction, or enzyme action to give the free acid, R1 represents a chlorine or bromine atom R2a and R2b, which may be the same or different each, represents an alkyl group having from 1 to 4 carbon atoms, an aryl group, and, A represents a direct bond or the residue of a dicarboxylic acid, and processes for their manufacture are provided. These, compounds are useful intermediates in the production of 7-oxo-4-thia-1-azabicyclo3,2,0-heptane and hept-2-ene derivatives, which in turn have antibacterial properties.