In the course of our synthetic works1) on anthracyclinones, 3) 6, 11- dihydroxynaphthacenequinone (I) 4) was found to be methylated with dimethyl sulfate in tetrahydrofuran to give four products, whose structures were established as II, III, IV and V. The naphthacenequinone (I) was synthesized from 2-(4-bromo-1-hydroxy-2-naphthoy1)- benzoic acid (VI) 5) by cvclization with boric acid and concentrated sulfuric acid, followed ...