Abstract
Reaction of diethyl allylmalonate (6b), sterically nucleophilic alkenes, Mn(OAc)3·2H2O and Cu(OAc)2·H2O gives methylenecyclopentanes 13 to 17 in 17–100% yield by an oxidative free-radical annulation. Similarly, oxidative annulation of diethyl crotylmalonate and ethyl benzylacetoacetate with an alkene gives vinylcyclopentane (30) and tetralin (35).