A → J Prostaglandin Swap:  A New Tactic for Cyclopentenone Prostaglandin Synthesis

A practical methodology for the synthesis of J-type prostaglandins has been developed starting from the well-consolidated approaches established for the synthesis of A-type prostaglandins. An efficient 1,3-allylic transposition of the C-9 hydroxyl group of intermediate 4 furnished the advanced precursor 5 for J₂ synthesis. Our optimized A−J swap protocol employed selenium chemistry, involving the [2,3] sigmatropic rearrangement of secondary allylic selenoxide 11a.