Thiele-Winter acetoxylation of quinones. Part IV. Quinones containing one or more t-butyl groups

Abstract

The acetoxylation of many 1,4- and 1,2-benzoquinones and two diphenoquinones containing one or more t-butyl groups has been studied; also most of the relevant earlier work has been repeated. The results show that acetoxylation rarely occurs ortho to a t-butyl group. In eight of the quinones studied the reaction resulted in replacement of a t-butyl by an acetoxy-group. A mechanism for this acetoxyde-t-butylation is proposed. One of the ortho-benzoquinones (5-methyl-3-t-butyl) reacted partly as such and partly in its tautomeric quinone methide form to give 1,2,4-triacetoxy-5-methyl-3-t-butylbenzene (20%) and 1,2-diacetoxy-5-acetoxymethyl-3-t-butylbenzene (14.5%).