Regio- and stereo-selectivity in the reactions of anions of aryl allyl sulfides with benzaldehyde

Abstract

Addition reactions of anions of aryl allyl sulfides to benzaldehyde proceed readily and in good yields and afford mixtures of products resulting from α- and γ-attack on the allyl anion. γ-Products pre- dominate, and the ratio of (E) : (Z) isomers usually surrounds unity, although in the case of the reaction involving 3-(phenylthio)but-1-ene the ratio is 10 : 1. The ratio of diastereoisomers formed in products resulting from α-attack ranges from 3 : 1 to 1.3 : 1 (starting from 3- (2,4,6-trimethyl-phenylthio)prop-1-ene and 2-methyl-3-(phenylthio)prop- 1-ene respectively).