The alkylation of the lithium enolate of enantiopure α-cyclohexylsulfinyl thioacetamide 1 with allyl bromides 5 possessing an electron-withdrawing group at thevinylic position does not occur at the sulfur center − asexpected in the sulfur series − but at the carbon centerthrough conjugate addition followed by bromide elimination.The modest to excellent 1,2-asymmetric induction achievedby the alkylsulfinyl group (dr up to 100:0) is explained byan electronic model.