SYNTHESES OF PGF2α AND CLOPROSTENOL

Abstract Prins reaction of norbornadiene leads to an efficient synthesis of the ketoacid ( 5 ) which is cleaved regio- and stereo-specifically with acids to 5- exo -substituted norbornan-2-one-7-carboxylic acids. Baeyer-Villiger oxidation of these ketones leads to bridged lactones, e.g. 18 , which can be converted into derivatives of the Corey aldehyde ( 1 ). In particular, the chlorolactone 19 is converted efficiently into the aldehyde 32 which, by four different routes, can be converted into known precursors of prostanoids.