Formation of seven- and eight-membered rings by Mn(III)-based oxidative free-radical cyclization

Article abstract of DOI:10.1016/S0040-4020(01)96189-7

Oxidative free-radical cyclizations of acetoacetates 1, 8, 17, and 20 with Mn(OAc)₃·2H₂ and Cu(OAc)₂·H₂O in acetic acid provide cycloheptenes and cyclooctenes in moderate to good yield. Tandem cyclizations of 28, 35 and 51 provide bicyclo[4.2.1]nonanes, bicyclo[5.2.1]decanes, bicyclo[5.3.0]decanes and bicyclo[6.3.0]undecanes.