Stereoselective generation of cis-2-lithio-3-CF3-oxirane via CF3-substituted β-oxido carbenoids. Highly stereoselective synthesis of CF3-substituted tri- and tetrasubstituted oxiranes and tetrasubstituted alkenes

Article abstract of DOI:10.1016/j.tet.2003.09.098

Treatment of 2-substituted 3,3-dichloro-1,1,1-trifluoropropan-2-ols with organolithium reagents R²Li in THF at -98°C stereoselectively produces 2,3-disubstituted 2-lithio-3-trifluoromethyloxiranes with Li and CF₃ cis. The reagents react with electrophiles El-X or organoboranes R³BR₂ to give CF₃-containing tri- and tetrasubstituted oxiranes or tetrasubstituted alkenes, respectively, with high diastereoselectivities.