Diastereoselective total synthesis of isocarbacyclin from L-ascorbic acid

Diastereoselective total synthesis of isocarbacyclin, which features a fused bicyclic key intermediate available from l-ascorbic acid, is described. The key intermediate was prepared in multigram quantities by the Pauson-Khand reaction of l-ascorbic acid-based (R)-4,4-diallyl-2,2-dimethyl-5-(trimethylsilyl)ethynyl-1,3-dioxolane (3), discriminating diastereotopic groups and faces of the geminal allyl substituents.