R)-3-HYDROXY-4,4-DIMETHYL-1-PHENYL-2-PYRROLIDINONE AND )-3-HYDROXY-4,4-DIMETHYL-1-PHENYL-2-PYRROLIDINONE, NEW CHIRAL AUXILIARIES FOR THE ASYMMETRIC-SYNTHESIS OF ALPHA-ARYLPROPANOIC ACIDS

Reaction of rac-alpha-arylpropanoyl chlorides with (R)- and S)-3-hydro xy-4,4-dimethyl-1-phenyl-2-pyrrolidinone (R)- and (S)-1, in the presen ce of triethylamine, under standard esterification conditions, gave (R ,R)- and (S,S)-3, respectively, with high diastereoselectivity. Contro lled acidic hydrolysis afforded the corresponding (R)- or (S)-alpha-ar ylpropanoic acids with high enantioselectivity, the chiral auxiliary b eing recovered efficiently.