4,5‐Dimethyl‐2‐Iodoxybenzenesulfonic Acid Catalyzed Site‐Selective Oxidation of 2‐Substituted Phenols to 1,2‐Quinols

A site-selective hydroxylative dearomatization of 2-substituted phenols to either 1,2-benzoquinols or their cyclodimers, catalyzed by 4,5-dimethyl-2-iodoxybenzenesulfonic acid with Oxone, has been developed. Natural products such as biscarvacrol and lacinilene C methyl ether could be synthesized efficiently under mild reaction conditions. Furthermore, both the reaction rate and site selectivity could be further improved by the introduction of a trialkylsilylmethyl substituent at the 2-position of phenols. The corresponding 1,2-quinols could be transformed into various useful structural motifs by [4+2] cycloaddition cascade reactions.