Toluene → 1,1-Dimethylethyl N-((1S,2S)-3-chloro-2-hydroxy-1-(phenylmethyl)propyl)carbamate

Participants

Reaction Conditions

Reaction Steps

To (3S)-3-tert-butoxycarbonylamino-1-chloro-4-phenyl-2-butanone (2.08 g) were added toluene (4.2 ml) and ethanol (16.7 ml). Sodium borohydride (133 mg) was added by portions at −10° C. and the mixture was stirred for 1 hr and 40 min. The reaction was quenched by adding acetic acid (0.40 ml). The reaction mixture was warmed to 60° C. over 1 hr and further stirred 60° C. for 30 min. The reaction mixture was then cooled to −10° C. over 1 hr and 50 min and further stirred at −10° C. for 6 hr. The obtained crystals were collected by filtration, washed with toluene (10.4 ml) and water of 0° C., and dried under reduced pressure to give the objective (2S,3S)-3-tert-butoxycarbonylamino-1-chloro-2-hydroxy-4-phenylbutane (1.52 g, yield 83%). The obtained dry crystals were analyzed by HPLC and found to be (2S,3S):(2R,3S)=99.2:0.8 crystals.

Provenance & Evidence