(R)- and (S)-3-fluorothalidomides:: Isosteric analogues of thalidomide

3-Fluorothalidomide, a nonracemizable isosteric analogue of thalidomide, was successfully prepared by perchloryl fluoride fluorination of a 3-phthalimidopiperidin-2-one derivative followed by RuO2 oxidation, In the preliminary biological evaluation of (R)- and (S)-enantiomers, it was shown that the (S)-isomer was found to be more active than both the (R)-isomer and the racemic thalidomide in lipopolysaccharide-induced TNF-a production enhancement produced from human peripheral blood lymphocytes cultivated in vitro.