Reaction of anthraquinone with some alkylmagnesium halides. Configuration and conformation of 9,10-diethyl- and 9,10-di-n-propyl-anthracene-9,10-diols

Abstract

The reaction of anthraquinone with a series of alkylmagnesium halides has been examined. With ethyl- or n-propylmagnesium bromide, the major product is a separable mixture of conformationally isomeric 9,10-diols resulting from 1,2-addition at both carbonyl groups, together with the hydroxyanthrone resulting from 1,2-addition at one carbonyl group. Isopropyl- and neopentyl-magnesium chloride resemble t-butylmagnesium halides in mainly undergoing 1,2- and 1,6-addition to anthraquinone.

The sterochemistry of the 9,10-dialkylanthracene-9,10-diols, formed as above, has been examined; the reaction has been shown to give mainly the (a′, a′)-with some cis-(e′, e′)-diol.