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.
