Mn(III)-Based Oxidative Cyclization of Alkenes Using Tricarbonyl System

摘要

abstract_textpThe Mn(III)-based oxidation of 1,1-disubstituted ethenes with 2-(2-aryl-2-oxoethyl)malonates, 2-acetyl-4-aryl-4-oxobutanoates, and 3-acetyl-1-arylpentane-1,4-diones was evaluated. The reaction using the malonates mainly gave the 2,3-dihydro-4H-pyran-4,4-dicarboxylates along with-lactones. A similar reaction using the acetyloxobutanoates and acetylpentanediones produced the 2,3,3a,6a-tetrahydrofuro2,3-bfurans and the corresponding dihydropyrans. The cyclization was strongly affected by the nucleophilicity of the carbonyl oxygen in the carbocation intermediate, and the kinetic and thermodynamic controls of the following reaction. The structure determination and the mechanisms are discussed./p/abstract_text