Three step synthesis of single diastereoisomers of the vicinal trifluoro motif

• Vincent A. Brunet,
• Alexandra M. Z. Slawin and
• David O'Hagan

Beilstein J. Org. Chem. 2009, 5, No. 61, doi:10.3762/bjoc.5.61

• diastereoisomeric series of this motif. The route is a significant improvement on an earlier six step strategy. Keywords: C–F bond; organo–fluorine chemistry; stereospecific fluorination; vicinal trifluoro motif; Introduction Selective fluorination is an important strategy for the design of performance molecules

• vicinal trifluoro motif as shown in Scheme 1 [11][12]. However this method had some limitations and particularly the final step was susceptible to competing elimination, resulting in poor yields. The route also required six steps to insert the three fluorine atoms, with a poor overall yield. A more

• second substrate of this diastereoisomeric series, and demonstrates a reasonably efficient protocol to the vicinal trifluoro motif, much improved over the original six step sequence [11][12]. Fluorination of the threo-α,β-epoxy alcohol 7a proved more challenging because of a propensity to give isomeric