Diastereoselective Synthesis of an Isoprostane: (±)-8-epi-PGF_2α Ethyl Ester

A total synthesis of the isoprostane (±)-8-epi-PGF_2α ethyl ester (5) is described, based on the diastereoselective cyclization of α-diazo ketone 7. This ketone is assembled by aldol condensation between α-diazo ketone 8 and aldehyde 9. The sequential α-diazo ketone aldol/insertion described here offers a powerful new approach to cycloalkane construction.