Anthraquinone & Anthrone Series: Part XXVI. A new synthesis of chrysophanol, rhein, islandicin, emodin & physcion

Abstract

A new general method for the synthesis of chrysophanol, rhein, islandicin, emodin and physcion, starting from common dye intermediates such as 1-amino-5-chloroanthraquinone and 2-methylanthraquinone, is described. Though a number of stages such as halogenation, deamination, replacement of halogen by hydroxyl, methoxylation and demethylation are involved in the synthesis, the reactions proceed without difficulty and good yields are obtained.