The Acetoxyfulvene Synthesis of Prostaglandins: A New, Versatile Synthesis of dl-PGF1δ, dl-PGF2α, dl-PGE1 and dl-PGE2 from a Common Intermediate

Abstract In the Corey1 synthesis of prostaglandins and in our recently published modifications2,3 a synthon containing carbon atoms 14 to 20θ is first added to a bicyclic intermediate (C-6 to C-13) and completion of the prostaglandin skeleton by addition of a second synthon containing carbon atoms 1 to 5 forms a subsequent step. In a modification4,5 of the Corey synthesis1 PGF1α and PGE1 were made by reversing the order in which these two synthons were added to the cyclopentane ring (C-6 to C-13). The major limitation of this modified route4,5 is that it is restricted to the preparation of prostaglandins of the 1-series,‡ because hydrogenolysis of the benzyl group of the intermediate ester (1) reduces the C-5, C-6 double bond to form the saturated alcohol (2), which cannot be converted into prostaglandins of the 2-series‡.