Enantioselective ring-opening of epoxides by HF-reagents: Asymmetric synthesis of fluoro lactones

The asymmetric ring opening of meso- and racemic-epoxides with different HF-reagents mediated by enantiopure (salen)chromium chloride provides optically active fluorohydrins with maximum 90% e.e. This reaction as well as lipase-catalyzed deracemization of a fluorohydrin is applied to synthesize a building block for the preparation of both enantiomers of a fluorinated analogue of the prostaglandin biosynthesis inhibitor lasiodiplodin using a cyclizing olefin metathesis reaction as a key-step.