Oxidation with Molecular Oxygen of the Cyclohexene Epoxide–Copper(II) Chloride–Ionol Ternary System

Abstract

The oxidation of the epoxide–chloride Cu (II)–an aromatic alcohol ternary system containing an alicyclic series epoxide derivative is studied for the first time. The concentration dependence of the rate of oxygen uptake by the CE–CuCl₂–IOL ternary system, where CE is cyclohexene epoxide and IOL is ionol, is expressed as V = k [CE]⁰ [CuCl₂]^0.6[IOL]^0.7 for [CE] $\gg$ [IOL] > [CuCl₂] in a methanol solution. The Arrhenius dependence of the effective oxidation rate constant in the temperature range 313–328 K has the form k = 8.0 × 10⁶ exp (–54.0/RT). A reaction mechanism based on the copper chloride-catalized electron transfer from the OH-bond of the substituted phenol to the C–O bond of the epoxide with the formation of an oxyalkyl radical is proposed. The free radical yield, estimated from the ratio of the rate of oxygen uptake to the rate of epoxide consumption, is ~50%.