Reversal of Stereoselectivity in the Aldol Reaction of Boron Enolate Derived from Oppolzer's Sultam with α,α-Difluoro and α,α,α-Trifluoro Carbonyl Compounds

Article abstract of DOI:10.1246/cl.1994.1135

Hexafluoroacetone causes the complete reversal of stereochemistry in the aldol reaction of boron enolate derived from Oppolzer's sultam in the absence of Lewis acids such as TiCl4.Trifluoroacetaldehyde and 2,2-difluoro-5-phenyl-1-pentanal cause partial re