Fluorination of α-phenylsulfanyl esters using difluoroiodotoluene

Treatment of α-phenylsulfanyl esters 11–14 with one equivalent of difluoroiodotoluene 3a produced the α-fluoro sulfides 17–20 in good overall yield through a Fluoro-Pummerer reaction. A second equivalent of reagent produced α,α-difluoro sulfides and a third led to α,α-difluoro sulfoxides. An identical pattern of reactivity was observed with the α-phenylsulfanyl lactone 26. This sequential fluorination–oxidation behaviour was exploited in the one-pot synthesis of 3-fluoro-2(5H)-furanone 33 starting from α-phenylsulfanylbutyrolactone 32.