Stereoselective formation of α-fluoro-α-trifluoromethyl-γ-lactones starting from γ-hydroxy-α,β-unsaturated sulfones and a hexafluoropropene-diethylamine adduct (PPDA)

Article abstract of DOI:10.1016/S0040-4039(97)01120-9

(E)-3-hydroxy-1-alkenyl p-tolyl sulfones (1) reacted with a hexafluoropropene-diethylamine adduct (PPDA) to afford α-fluoro-α-(trifluoromethyl)-β-[(p-tolylsulfonyl)methyl]-γ-lactones (2). This reaction is so stereoselective that only one diastereomer of 2 is detected in the reaction mixture. A plausible mechanism for this intriguing reaction is discussed.