Reactions of lead tetra-acetate. Part XX. Oxidation of 2,4,6-tri-t-butylphenol

Abstract

Oxidation of 2,4,6-tri-t-butylphenol with lead tetra-acetate in acetic acid, benzene, or dichloromethane gives 2-acetoxy-2,4,6-tri-t-butylcyclohexa-3,5-dienone, 4-acetoxy-2,4,6-tri-t-butylcyclohexa-2,5-dienone, and bis-(1,3,5-tri-t-butylcyclohexadienone) peroxide; the relative amounts of the two acetoxy-derivatives do not vary with the solvent or when reaction is carried out under nitrogen. In the presence of methanol, the methoxy-analogues of the acetoxy-derivatives are also formed, and this, together with the finding that the 2,4,6-tri-t-butylphenoxyl radical is relatively inert towards lead tetra-acetate, provides evidence that the cyclohexadienone products are derived from two-electron oxidations.