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.
Ingold
K U
KU
National Research Council of Canada, Ottawa, Ontario, Canada K1A 0R6. keith.ingold@nrc.ca
Smeu
Manuel
M
Dilabio
Gino A
GA