Synthesis of valsarin and 5,7-dichloroemodin
Abstract
Syntheses of the naturally occurring chloroanthraquinones 5,7-dichloroemodin (2)(1,3-dichloro-2,4,5-trihydroxy-7-methylanthraquinone) and valsarin (1)(3-chloro-1,2,4,5-tetrahydroxy-7-methylanthraquinone) and a new synthesis of 7-chloroemodin(3)(2-chloro-1,3,8-trihydroxy-6-methylanthraquinone) are described.