The synthesis of both enantiomers of alpha-(trinuoromethyl)butyrine and alpha-(trifluoromethyl)phenylalanine was accomplished by desulfurization and deprotection of the beta-trifluoromethyl sulfoxides, obtained in the condensation of the corresponding optically pure alkyl p-tolyl sulfoxides with N-alkoxycarbonylimines of methyl 3,3,3-trifluoropyruvate.