Asymmetric formylation of chiral vinyl sulfosides using tetra-n-butylammonium peroxydisulfate

Abstract

Tetra-n-butylammonium peroxydisulfate [$(n-Bu_4N)_2S_2O_8$] has been successfully prepared and turned out to be a useful source of tetra-n-butylammonium sulfate radical in organic solvents. Various alkenes reacted with tetra-n- butylammonium peroxydisul fate in anhydrous 1,3-dioxolane to give one carbon homologated products which were typed as β-masked formylating form. Vinyl p-tolyl sulfoxides with the optically active center at the sulfur atom have been used successfully in various asymmetric syntheses. We have examined that the asymmetric addition of 1,3-dioxolane to various vinyl chiral sulfoxides using tetra-n-butylammonium peroxydisulfate. When (-) - (R) - (Z)- propenyl p-tolyl sulfoxide reacted with 1,3-dioxolane in the presence of tetra-n-butyl ammonium peroxydisulfate and Lewis acid, titanium we could obtain 1,3-dioxolanylated adduct with good diastereoselectivity.