Abstract A regioselective pathway for the radical reaction of 1-alken-3-ynes with β- dicarbonyl compounds, mediated by Mn (OAc) 3, can be achieved by protection of the substrate triple bond with a hexacarbonyldicobalt moiety. Dihydrofuran and hexahydrobenzofuran derivatives are formed by intermolecular oxidative cyclization of intermediate cobalt-complexed propargyl radicals.
