Polar Effects in the Decomposition of Bis(3-alkoxyaroyl) Peroxides. Synthesis of 8-Alkoxy-6H-dibenzopyran-6-ones

Article abstract of DOI:10.1021/jo00313a018

The reaction of four substituted bis(3-alkoxybenzoyl) peroxides (1b-e) in neat phenols (2a-e) affords mainly 8-alkoxy-6H-dibenzopyran-6-ones (7) and ortho-benzoyloxylation products (4) of the phenol.Diaroyl peroxides without electron-releasing meta substituents afford essentially products 4.A mechanism involving monoelectronic oxidation of the phenol by the peroxide and biaryl coupling by preferential addition of the phenol radical cation to the ortho positions to the alkoxy group of the diaroyl peroxide is suggested.