Ring-opening hydrofluorination of enantiomerically pure (2S,3S)-3-arylglycidyl ethers (aryl = phenyl, 4-trifluoromethylphenyl) by boron trifluoride-diethyl ether under mild conditions provides ß-fluoro alcohols in good yield in a stereospecific manner with complete regiocontrol.
![Boron trifluoride-induced reactions of phenylglycidyl ethers: A convenient synthesis of enantiopure, stereodefined fluorohydrins](https://www.iciq.org/wp-content/uploads/2014/03/Boron-trifluoride-induced-reactions-of-phenylglycidyl-ethers-A-convenient-synthesis-of-enantiopure-stereodefined-fluorohydrins_eng_noticies_articles_2004_7.gif)