Colouring matters of Australian Plants. V. Haemocorin: The chemistry of the Aglycone

Abstract

Oxidation of the aglycone dimethyl ether B gives a cyclic anhydride isomeric with that previously obtained from dimethyl ether A. The chemical properties and absorption spectra of the two anhydrides and their derivatives suggest that they are dimethoxyphenylnaphthalic anhydrides with the methoxyl groups attached to the naphthalene ring system. Further degradation of the anhydrides eventually gives diphenyl-2,3,4-tricarboxylic acid. This is proved by decarboxylation to diphenyl and by the formation of an anilide phenylimide identical with a synthetic specimen. These results indicate that the aglycone is a dihydroxymethoxyphenylperinaphthenone, and further support is given by a study of model hydroxyperinaphthenones.