Mn(III)-based oxidative free radical cyclizations of unsaturated 2-cyclohexenones and aldehydes

Article abstract of DOI:10.1016/0040-4020(96)00234-7

Oxidative free-radical cyclizations of unsaturated 2-cyclohexenones 9a, 9b, 17, and 24 with Mn(OAc)₃ afford unsaturated α'-keto radicals such as 10 that cyclize to afford bicyclic products. The major process with 2-cyclohexenone 27 is conjugate addition of acetate to form β-acetoxy α-keto radical 37. Unsaturated aldehydes 45,57a, and 57b are oxidized to radicals that cyclize to give cyclopentane- and cyclohexanecarboxaldehydes.