Spirolactones of Xanthene. IV. New Method of Xanthone Synthesis by Oxidation of Novel Spirolactones of Dibenzo [c, h] xanthene and Xanthenes

Abstract

Dibenzo [c, h] xanthone and halogen-and methyl-substituted xanthones have been synthesized by the oxidation of novel spirolactones of dibenzo [c, h] xanthene and xanthene, which were prepared by a new condensation reaction of 1-naphthol or phenol derivatives with oxalic acid in the presence of sulfuric acid. The oxidation was carried out by using potassium permanganate in the presence of aqueous potassium hydroxide. The dibenzo [c, h] xanthone and xanthones were identical with samples obtained by another synthetic route.