tert-butyl N-[(2R,3S)-1,4-dichloro-3-hydroxybutan-2-yl]carbamate

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a stirred solution of 2(R)-(t-butyloxycarbonyl)amino-1,4-dichloro-3(S)-hydroxybutane (100.0 mg, 0.389 mmol) in dry DMF (2.5 mL) were added imidazole (79.4 mg, 1.67 mmol), DMAP (4.8 mg, 0.039 mmol) and TBS-Cl (175.9 mg, 1.167 mmol) at room temperature under N2. The resulting solution was stirred at 50° C. for 12 h. The reaction mixture was diluted with EtOAc (30 mL), washed with 0.1 N citric acid solution (5 mL), sat aqueous NaHCO3 (5 mL), water (5 mL) and brine (5 mL), dried over anhydrous magnesium sulfate, filtered, concentrated and column-chromatographed (10% EtOAc in n-Hex) to provide 2(S)-t-butyldimetylsilyloxy-3(R))-(t-butyloxycarbonyl)amino-1,4-dichlorobutane as a colorless solid (144.6 mg) washed with 0.1 N citric acid solution (5 mL) dried over anhydrous magnesium sulfate filtered concentrated column-chromatographed (10% EtOAc in n-Hex)