Multicomponent Strategy for the Synthesis of Prostaglandin E2 Methyl Ester under Anion Relay Chelation Control

Starting with four components, the enantioselective synthesis of prostaglandin E-2 methyl ester has been achieved through a highly stereoselective heteroatom-directed conjugate addition reaction and cyclopentanone ring cydization as the key steps. This asymmetric strategy includes (i) an asymmetric Reformatsky reaction; (ii) conjugate addition of a chiral vinyllithium reagent; (iii) cyclization to form a sulfonylated cyclopentanone in one-pot; followed by (iv) allylation of the side chain. Four carbon-carbon 'bond-forming processes and three stereogenic centers were established, with the steps from (ii) to (iii) being achieved in a one-pot process.