Synthesis of Sulfonylated Lactones via Ag-Catalyzed Cascade Sulfonylation/Cyclization of 1,6-Enynes with Sodium Sulfinates

A novel strategy for the synthesis of sulfonylated lactones via Ag-catalyzed radical addition/cyclization reaction of 1,6-enynes and sodium sulfinates has been developed. The reaction presents high stereoselectivity under mild conditions with C4 prochiral center construction in one step. The ESR experiments and relevant mechanistic studies indicated that a radical pathway should be involved in this transformation.