| Abstract
| - Peroxidation of ketones and aldehydes with iodine as a catalyst was studied. Ketones reacted with 30%aq hydrogen peroxide in the presence of 10 mol % of iodine to yield gem-dihydroperoxides in acetonitrileand hydroperoxyketals in methanol. The yield of hydroperoxidation of various cyclic ketones was 60−98%, including androstane-3,17-dione, while acyclic ketones were converted with a similar efficiency.Aromatic aldehydes were also converted to gem-dihydroperoxides with hydrogen peroxide and iodine ascatalyst in acetonitrile and to hydroperoxyacetal in methanol, while the reactivity of aliphatic ones remainedthe same as in noncatalyzed reactions. tert-Butylhydroperoxide reacted in a similar manner, giving thecorresponding perether derivatives. A study was also made of the relative kinetics of dihydroperoxidationfrom which the Hammet equation gave a reaction constant (ρ) of −2.76, indicating the strong positivecharge development in the transition state and the important role of rehybridization in the conversion ofhydroperoxyhemiketal to gem-dihydroperoxide. In acetonitrile, the iodine catalyst is apparently able todiscriminate between the elimination of a hydroxy, methoxy, and hydroperoxy group and addition ofwater, methanol, and H2O2 to a carbonyl group.
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