Nalpha-Tosyl-L-phenylalanine chloromethyl ketone → (2R, 3S)-3-(p-toluenesulfonyl)amino-1-chloro-2-hydroxy-4-phenylbutane

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Reaction Steps

(3S)-3-(p-Toluenesulfonyl)amino-1-chloro-4-phenyl-2-butanone (175.9 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 (0.67 mg, 0.001 mmol, s/c=500) in ethyl acetate (0.5 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-(p-toluenesulfonyl)amino-1-chloro-2-hydroxy-4-phenylbutane (173.5 mg; yield: 98.3%). HPLC analysis revealed that the production ratio of the desired (2R,3S)-form to the isomeric (2S,3S)-form, (2R,3S):(2S,3S), was 10.9:1. The results of elementary analysis were as follows.

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