Abstract: Reaction of carbonyl compounds with vinyllithium reagents followed by quenching with benzenesulfenyl chloride produces the allylic sulfoxide resulting from [2, 3]-sigmatropic rearrangement. Sulfenylation of the corresponding anion results in a net isomerization of the allylic sulfoxide into a y-hydroxy-a, P-unsaturated thioether. Hydrolysis to the enone or enal accomplishes the equivalent of a directed aldol condensation. Application to carbonyl ...