A Convenient Synthesis of 5-Substituted-2,3-Dihydrothiophenes

Abstract

Treatment of γ-thiobutyrolactone with KHMDS and N-(5-chloro-2-pyridyl)triflimide (Comin’s reagent) gives the corresponding thiolenoltriflate in good yields. Coupling of the thiolenoltriflate with Gilman cuprates proceeds smoothly to give the 5-substituted-2,3-dihydrothiophenes. The synthesis of a homochiral thiolactone is described. Conversion to the corresponding thiolenoltriflate proceeds in good yield using the conditions described above. The coupling with Gilman cuprates gives homochiral 5-substituted-2,3-dihydrothiophenes in good yield.