Stereoselective synthesis of an isoprostane synthon via 8,12-free-radical cyclization

Aiming at a stereocontrolled biomimetic synthesis of isoprostanes a fully stereocontrolled 8,12-free radical cyclization has been achieved via intermediate 10 by annulating an endocyclic radical to a butenolide acceptor double bond. In this way ent-12-epi-PGF2α (ent-2) can be prepared.