1, 3, 11-Trimethoxynaphthacenequinone (V) and 1, 3-dimethoxyanthraquinone (XIII) were prepared as shown in Charts 1 and 2. Reduction with sodium hydrogensulfite in alkaline medium converted the quinones, (V), (XIII) and 6-methoxynaphthacenequinone (XV), to 1, 3, 11-trimethoxy-5 (12H)-naphthacenone (VI), 2, 4-dimethoxyanthrone (Xff) and 11-methoxy-5 (12H)-naphthacenone (XVI), respectively.
