(3S)-3-Benzyloxycarbonylamino-1-chloro4-(p-fluorophenyl)-2-butanone (174.9 mg, 0.5 mmol) and a formic acid/triethylamine azeotropic mixture (0.1 ml) were added to a solution of chloro(pentamethylcyclopentadienyl)rhodium (III) (1R,2R)-N-(p-toluenesulfonyl)-1,2-diphenylethylenediamine (0.34 mg, 0.0005 mmol, s/c=1000) in ethyl acetate (1.0 ml), followed by stirring at room temperature for 2 hours. After completion of the reaction, the reaction mixture was purified by silica gel column chromatography to give a desired compound, (2R,3S)-3-benzyloxycarbonylamino-1-chloro-2-hydroxy-4-(p-fluorophenyl)butane (166.2 mg; yield: 94.4%). As a result of HPLC analysis, the production ratio of the desired (2R,3S)-form to the isomeric (2S,3S)-form, (2R,3S):(2S,3S), was 6.7:1. The results of elementary analysis were as follows.
