Lignans and related phenols. Part XIV. Selective oxidation of aryltetrahydronaphthalenes
Abstract
The selective oxidation of aryltetrahydronaphthalene lignans by periodate and Fremy's salt has been demonstrated. Steric factors were evident in the reactions of the 5,8-quinone (II), which only underwent Thiele acetylation following its isomerisation to the flexible ‘picro’ derivative (III). U.v. irradiation of the quinone afforded a novel synthesis of a wholly aromatic analogue (V). Configurations were assigned on the basis of c.d. measurements.