The mechanism of the permanganate oxidation of di-and tri-arylcarbinols has been studied in aqueous sulfuric acid. With both kinds of alcohols the rate-controlling step in solutions more acidic than Ho -0.50 was found to be the ionization of the carbinol to give the carbonium ion followed, it is believed, by rapid reaction with permanganate ion to form the ester which decomposes rapidly to products. In the case of the tertiary alcohols the decomposition probably proceeds via a 1,2-aryl shift. The effect of substituents is correlated with o + in both cases, p+ being -1.02 and -1.39 for the secondary and tertiary series. The acidity function which governs both reactions is Ho. Tri(p-toly1)carbinol is exceptional in that its oxidation in solutions more acidic than HR -2.6 is second-order and is governed by the H, acidity function.

The mechanism of the chromic acid oxidation of di-and tri-aryl carbinols has been studied in 80 wt % acetic acid containing sulfuric acid. The reactions are cleanly second-order and give benzophenones in the case of the secondary alcohols and benzophenones plus phenols in the case of the tertiary alcohols. Electron-donating substituents in the tertiary alcohol appear predominantly in the phenol component and the rate-controlling step is believed to be a 1,2-aryl shift. The reaction constant for the migration is pf = -1.44 and that for the overall reaction is pf = -0.879. The presence of manganous ions does not alter these values although it lowers the overall rate of reaction. Although an analogous 1,Zhydride shift mechanism can be written for the oxidation of the secondary alcohols, there are enough points of difference between the oxidations of the secondary and tertiary systems to make this appear unlikely.

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