Catalytic Hypervalent Iodine Oxidation of p-Dialkoxybenzenes to p-Quinones Using 4-Iodophenoxyacetic Acid and Oxone^®

Abstract

A catalytic hypervalent iodine oxidation of p-dialkoxybenzenes using 4-iodophenoxyacetic acid (1) and 2KHSO_{5 · KHSO}4 · K₂SO₄ (Oxone^®) was developed. Reaction of p-dialkoxybenzenes (2) with a catalytic amount of 1 in the presence of Oxone^® as a co-oxidant in 2,2,2-trifluoroethanol–water (1 : 2) gave the corresponding p-quinones (3) in excellent yields without purification. This procedure was applied to synthesis of blattellaquinone (9), the sex pheromone of the German cockroach, Blattella germanica.