Three step synthesis of single diastereoisomers of the vicinal trifluoro motif

A three step route to single diastereoisomers of the vicinal trifluoromethyl motif is described. The route starts from either syn- or anti-alpha,beta-epoxy alcohols and takes a direct approach in that each of the three steps introduces a fluorine atom in a regio- and stereospecific manner. Starting from either the syn- or the anti-alpha,beta-epoxy alcohol, stereospecific reactions generate two separate diastereoisomeric series of this motif. The route is a significant improvement on an earlier six step strategy.