Rearrangement and Decomposition of Phosphoranyl Peroxides Produced in situ from Alkylidenephosphoranes and t-Alkylperoxy Anions

Abstract

Abstract The reactions of alkylidenephosphoranes(I), produced in situ from the corresponding phosphonium salts and sodium ethoxide, with sodium salt of t-butyl hydroperoxide (II) were carried out in absolute ethanol. Carbanion (III) of phosphoranyl peroxide, formed by the reaction of I with II, underwent a rearrangement to produce t-butyl phenyl ether, alkyl t-butyl ether, and two kinds of phosphine oxides. Phosphoranyl peroxide (IV), formed by abstraction of proton from ethanol, decomposed in homolytic fashion to yield t-butyl alcohol and hydroxyphosphorane (V) as an intermediate, the decomposition of which gave benzene, hydrocarbon and corresponding phosphine oxides. Homolytic decomposition of IV was supported by the reaction of tetraphenylphosphonium bromide with II. The contribution of III was confirmed by the effect of base concentration on the amounts of rearrangement products. The reaction with cumylperoxy anion gave similar results. The mechanisms of these reactions were discussed.