C-Alkylation of 1,3-dihydroxyanthraquinones. Total syntheses of (±)-averufin and (±)-bipolarin

Abstract

Various methods of substituting 1,3-dihydroxyanthraquinones in the 2-position were investigated. It was eventually found that direct hydroxyalkylation in the presence of definite amounts of sodium bicarbonate could be carried out. The reaction of 1,3,6,8-tetrahydroxyanthraquinone with 5-oxohexanal or 4-hydroxybutanal gave, respectively, among other products, (±)-averufin and (±)-bipolarin.