A CONVENIENT SYNTHESIS OF 5-SUBSTITUTED-2,3-DIHYDROTHIOPHENES

Treatment of gamma-thiobutyrolactone with KHMDS and N-(5-chloro-2-pyri dyl)triflimide (Comin's reagent) gives the corresponding thiolenoltrif late in good yield. Coupling of the thiolenortriflate with Gilman cupr ates proceeds smoothly to give the 5-substituted-2,3-dihydrothiophenes . The synthesis of a homochiral thiolactone is described. Conversion t o the corresponding thiolenoltriflate proceeds in good yield using the conditions described above. The coupling with Gilman cuprates gives h omochiral 5-substituted-2,3-dihydrothiophenes in good yield.