Colouring matters of the Aphidoidea. XLV. Synthesis of (±)-deoxyquinone A dimethyl ether and its epimer (±)-cis-7,9-Dimethoxy-1,3-dimethyl-3,4,5,10-tetrahydro-1 H-naphtho[2,3-c]pyran-5,10-dione [(±)-7-Methoxyeleutherin]

Abstract

(±)-Deoxyquinone A dimethyl ether (1) has been synthesized from 5,7-dimethoxy-1-naphthol. This is the first synthesis of an aphin-derived pyranonaphthoquinone, the (+)-enantiomer having been obtained from natural sources. The (±)-cis epimer (3),7-methoxyeleutherin, a plant product, was also obtained for the first time.