Addition reactions of esters of Feist's acid

Abstract

The double bond in dimethyl and diethyl 3-methylenecyclopropane-trans-1,2-dicarboxylate is reactive towards radical addition of thiophenol, bromotrichloromethane, and benzaldehyde, to give the normal adducts of terminal olefins; no evidence was found for participation of a non-classical cyclopropylmethyl radical. The double bond could not be epoxidised but reacted readily with ethyl diazoacetate to give the spiropentane esters.

The bromine adducts of the unsaturated esters react with nucleophiles at the primary rather than at the tertiary bromine.