Isomerization of triphenylmethoxyl and 1,1-diphenylethoxyl radicals. Revised assignment of the electron-spin resonance spectra of purported intermediates formed during the ceric ammonium nitrate mediated photooxidation of aryl carbinols

Grossi and Strazzari have reported (J. Org. Chem. 2000, 65, 2748-2754) that the ceric ammonium nitrate modulated photooxidation of triphenylmethanol and 1,1-diphenylethanol yielded ESR spectra of the putative spiro-cyclohexadienyl intermediates in the O-neophyl rearrangements of the corresponding alkoxyl radicals, Ph₂(R)CO^. (R = Ph, CH₃), to the phenoxymethyl radicals, Ph(R)C^.OPh. Both ESR spectra are reassigned to the phenoxyl radical, C₆H₅O^., and the probable mechanism by which phenoxyl is formed in these systems is presented.