A variety of cyclic and acyclic allylic alcohols undergo efficient chemo-, regio- and/or stereoselective epoxidations in neutral aqueous solutions of amphiphilic carbohydrates (sucrose, L-arabinose, methyl or ethyl beta-D-fructopyranoside) by using dilute hydrogen peroxide in the presence of molybdic or tungstic salts.
α,β,γ-Trifluoroalkanes: A Stereoselective Synthesis Placing Three Vicinal Fluorines along a Hydrocarbon Chain
作者:Marcello Nicoletti、David O'Hagan、Alexandra M. Z. Slawin
DOI:10.1021/ja045299q
日期:2005.1.1
motif. The methodology relied upon regiospecific and stereospecific hydrogenfluorideringopening of allylic epoxides and then Sharpless cyclic sulfate methodology followed by nucleophilic fluoride attack to introduce the second fluorine. The resultant difluoro alcohol was converted to its triflate which was also displaced by fluoride ion to generate the alpha,beta,gamma-trifluoroalkanes.