Efficient Synthesis of Polysubstituted Tetrahydrothiopyran Sulfoxides by the Reaction of α,β-Unsaturated Ketones and Na2S

A catalyst-free condensation reaction of α,β-unsaturated ketones and sodium sulfide in CH3CN-H2O mixture (1:1) was established to prepare a variety of polysubstituted tetrahydrothiopyrans in good to excellent yields. The obtained tetrahydrothiopyrans were oxidized with MCPBA to the corresponding sulfoxides in good yields. The present research is the first report on synthesis of polysubstituted tetrahydrothiopyran sulfoxides