Abstract 2-Dimethylsulfonioalkane-1-sulfonates were formed by the reaction of α-olefins with the dimethyl sulfide-sulfur trioxide complex. The treatment of these products with alkali gave Δ1-alkene-1-sulfonates quantitatively. In the reaction between 1,2-epoxyalkanes and the dimethyl sulfide-sulfur trioxide complex, 1-dimethylsulfoniomethyl-1-alkyl sulfate was formed exclusively. 1-Dimethylsulfonio-1-alkenes were quantitatively formed upon the treatment of these products with alkali. The chemical structures of these compounds have been established, and the reaction routes were discussed.