Dimethylsulfoxide oxidation with a hydroperoxide. Isolation and characterization of the peroxidic reaction intermediate

The reaction between a hydroxyhydroperoxide (1-hydroperoxy-1-[p-nitrophenyl ]-ethanol) with dimethylsulfoxide (DMSO) in the 15 degrees -19 degreesC tem perature range yields p-nitroacetophenone and dimethylsulfone in stoichiome tric amounts. The reaction in DMSO and in acetonitrile solutions follows ps eudo first-order kinetic laws, which allow to assess the corresponding ener gy of activation (11.2 kcal (.) mol(-1) and 14.1 kcal (.) mol(-1), respecti vely). These values suggest a significant solvent effect on the reactions. By a preparative paper chromatography technique in the reaction performed i n DMSO, a thermally labile peroxidic intermediate was isolated and further characterized by H-1 NMR and C-13 NMR analyses.