Conversion of tri-O-methylsolorinic acid into tetra-O-methylaverythrin, the synthesis of averythrin, and the synthesis of some partially methylated 1,3,6,8-tetrahydroxy-2-methylanthraquinones
Abstract
Synthetic tri-O-methylsolorinic acid (VI) has been converted into (±)-tetra-O-methylaverantin (X), and thence into tetra-O-methylaverythin (VII). Demethylation of synthetic tri-O-methyldihydroaverythin (VIII) gave after acetylation and bromination with N-bromosuccinimide the bromo-compound (XII). Dehydrobromination and hydrolysis of the latter gave averythrin (II). Syntheses of some partially methylated poly-hydroxy-anthraquinones are described.