Chemistry of the Coccoidea. X. Synthesis of the xantholaccaic acid B system and of related compounds

Abstract
Xantholaccaic acid B dimethyl ester pentamethyl ether (6) and some related anthraquinones have been synthesized by regiospecific Diels-Alder addition of the highly functionalized dienes (12) and (27) successively to 2,6-dichloro-1,4-benzoquinone. This is the first synthesis of the ?-arylanthraquinone skeleton characteristic of the water-soluble dyestuffs from lac insects.