An oxidative desulfurization–fluorination protocol has been used to synthesize (2S)-2- (difluoromethyl)-N-tosylpyrrolidine (6a) and (2S)-2-(trifluoromethyl)-N-tosylpyrrolidine (7a) from the (2S)-prolinol-derived (2S)-2-(4-chlorophenylthiomethyl)-N-tosylpyrrolidine (9) or (2S)-2-(dithian-2-yl)-N-tosylpyrrolidine (5). Efforts to prepare 3, 3-difluoroalanine similarly from an N-protected S-aryl-cysteine ester 17 gave only traces of the target compound 18. ...