Oxidation of alkoxyphenols. Part X. The reaction of 2,2′-dihydroxy-5,5′-dimethoxy-3,3′-di-t-butylbiphenyl with lead tetra-acetate

Abstract

Oxidation in acid solution converts 2,2′-dihydroxy-5,5′-dimethoxy-3,3′-di-t-butylbiphenyl into 3,3′-di-t-butyl-biphenyl-2,5:2′,5′-diquinone, and in benzene into 6a-acetoxy-4,6a-dihydro-5′-methoxy-4-oxo-3′,6-di-t-butyl-benzoxet-2-spiro-1′-cyclohexa-3′,5′-dien-2′-one. The latter's structure is shown by reductive acetylation to a tetra-acetoxy- and a diacetoxy-biphenyl and an acetoxydibenzofuran. The oxidation proceeds through 4,5′-dimethoxy-3′,6-di-t-butylbenzoxet-2-spiro-1′-cyclohexa-3′,5′-dien-2′-one. The reductive acetylation, Thiele acetylation, and reaction with alcohols of this intermediate are also examined.