Vinylcyclopentene synthesis via phenylthio radical catalyzed addition of electron deficient alkynes to substituted vinylcyclopropanes

Treatment of either t-butyl ester- or benzylether-substituted vinylcyclopropanes with an excess of ester- or sulfone-bearing alkynes in the presence of phenylthio radical in benzene afforded moderate yields of functionalized vinylcyclopentene products as mixtures of stereoisomers.