PREPARATION OF (R)-3-HYDROXY-2-(TRIFLUOROMETHYL)PROPIONIC AND (S)-3-HYDROXY-2-(TRIFLUOROMETHYL)PROPIONIC ACID BY RESOLUTION WITH (R,R)-2-AMINO-1-PHENYLPROPANE-1,3-DIOL AND (S,S)-2-AMINO-1-PHENYLPROPANE-1,3-DIOL

Racemic 2-trifluoromethyl-3-hydroxypropionic acid (rac-1) is prepared on a 50 g scale from 3,3,3-trifluoropropene in four steps, the overall yield being 40%. A procedure for the resolution of rac-1 with 2-amino -1-phenylpropane-1,3-diol is described (25 g scale). The acids (R)-1 a nd (S)-1 are isolated, their enantiomer purities determined by GC anal ysis of the corresponding methyl esters on a chiral column and their c hirality senses assigned from an X-ray crystal structure of the salt f ormed with phenylethylamine. The non-fluorinated analog of 1 is freque ncy employed as a chiral synthetic building block ('Roche acid').