Studies on the formation of complex oxidation and condensation products of phenols. Part III. -Rearrangements of oxidation-reduction type in the diquinone group

Abstract

The diquinones have been but little investigated, and as they contain two condensed highly active quinonid systems it is to be anticipated that they should be capable of interesting intramolecular reactions. When heated to 210-215º, 4 : 4'-dimethoxydiquinone is rapidly converted into a red crystalline isomeride (yield, 90%), soluble in alkali with an intense blue colour, and yielding a mono-acetate indicating the occurrence of a free hydroxyl group. Two hydrogen atoms are taken up on reduction, and the phenolic product yields a triacetate and a trimethyl ether. It follows that of the four carbonyl oxygens of 4 : 4'-dimethoxydiquinone, one has been converted into a hydroxyl group, and another which does not exhibit any functional activity, is probably present as ethereal oxygen. These results led to formula (III) as representing the product of rearrangement.