Unusual regio- and stereo-chemistry in the reaction of methyl (E)- and (Z)-β-styryl sulphone with pyrrolidin-1-yl-4-t-butylcyclohexene

Abstract

Pyrrolidin-1-yl-4-t-butylcyclohexene undergoes both antiparallel and parallel attack in the reaction with methyl (E)- and (Z)-β-styryl sulphone. Moreover, the addition is regiospecific with respect to each starting sulphone in fact the Z-isomer reacts almost exclusively at the carbon atom α to SO₂, whilst the E-isomer reacts, although in poor yield, only at the β-carbon. The structures of the 2-substituted-4-t-butylcyclohexanones, obtained by hydrolysis of the reaction mixtures, have been established by n.m.r, analysis and by the results of equilibration reactions in acidic and/or basic media.