Friedel–Crafts Condensations with Maleic Anhydrides. III. The Synthesis of Polyhydroxylated Naphthoquinones

Abstract

The condensation of hydroquinone ethers with an excess of dihalomaleic anhydrides has been found to give particularly good yields of dihalonaphthazarins. The etherification of the latter and the nucleophilic substitution of 2,3-dichloronaphthoquinones have been examined. Finally the structures of the products obtained from the Fries rearrangement of polyacetoxynaphthalenes have been definitively established.