tert-butyl N-[(2R)-4-chloro-3-oxo-1-phenylbutan-2-yl]carbamate

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a stirred solution of (R)-1-Benzyl-3-chloro-2-oxopropylcarbamic acid tert-butyl ester (8.0 g, 27 mmol) in THF/water (200 mL, 9/1, v/v) at 0° C. is added NaBH4 (1.23 g, 32 mmol). After 30 min the mixture is concentrated under reduced pressure and the residue is suspended in a mixture of water and ethyl acetate (1:1, v/v). This mixture is cooled to 0° C. and the pH is adjusted to ˜2 by the slow addition of 2M NaHSO4. The phases are separated and the organic layer is washed with water and brine, dried over Na2SO4 and concentrated under reduced pressure to afford a white solid as a mixture of diastereomers (7.92 g, 27 mmol, ˜5:2 R,R:R,S), which is purified using General Purification Procedure C to afford the title compound as a white solid (4.45 g, 15 mmol). After 30 min the mixture is concentrated under reduced pressure the residue is suspended in a mixture of water and ethyl acetate (1:1 the pH is adjusted to ˜2 by the slow addition of 2M NaHSO4 The phases are separated the organic layer is washed with water and brine dried over Na2SO4 concentrated under reduced pressure to afford a white solid as a mixture of diastereomers (7.92 g, 27 mmol, ˜5:2 R,R:R,S), which is purified General Purification Procedure C

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a stirred solution of (R)-1-Benzyl-3-chloro-2-oxopropylcarbamic acid tert-butyl ester (8.0 g, 27 mmol) in THF/water (200 mL, 9/1, v/v) at 0° C. is added NaBH4 (1.23 g, 32 mmol). After 30 min the mixture is concentrated under reduced pressure and the residue is suspended in a mixture of water and ethyl acetate (1:1, v/v). This mixture is cooled to 0° C. and the pH is adjusted to ˜2 by the slow addition of 2M NaHSO4. The phases are separated and the organic layer is washed with water and brine, dried over Na2SO4 and concentrated under reduced pressure to afford a white solid as a mixture of diastereomers (7.92 g, 27 mmol, ˜5:2 R,R:R,S), which is purified using General Purification Procedure C to afford the title compound as a white solid (4.45 g, 15 mmol). After 30 min the mixture is concentrated under reduced pressure the residue is suspended in a mixture of water and ethyl acetate (1:1 the pH is adjusted to ˜2 by the slow addition of 2M NaHSO4 The phases are separated the organic layer is washed with water and brine dried over Na2SO4 concentrated under reduced pressure to afford a white solid as a mixture of diastereomers (7.92 g, 27 mmol, ˜5:2 R,R:R,S), which is purified General Purification Procedure C

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a stirred solution of (R)-1-Benzyl-3-chloro-2-oxopropylcarbamic acid tert-butyl ester (8.0 g, 27 mmol) in THF/water (200 mL, 9/1, v/v) at 0° C. is added NaBH4 (1.23 g, 32 mmol). After 30 min the mixture is concentrated under reduced pressure and the residue is suspended in a mixture of water and ethyl acetate (1:1, v/v). This mixture is cooled to 0° C. and the pH is adjusted to ˜2 by the slow addition of 2M NaHSO4. The phases are separated and the organic layer is washed with water and brine, dried over Na2SO4 and concentrated under reduced pressure to afford a white solid as a mixture of diastereomers (7.92 g, 27 mmol, ˜5:2 R,R:R,S), which is purified using General Purification Procedure C to afford the title compound as a white solid (4.45 g, 15 mmol). After 30 min the mixture is concentrated under reduced pressure the residue is suspended in a mixture of water and ethyl acetate (1:1 the pH is adjusted to ˜2 by the slow addition of 2M NaHSO4 The phases are separated the organic layer is washed with water and brine dried over Na2SO4 concentrated under reduced pressure to afford a white solid as a mixture of diastereomers (7.92 g, 27 mmol, ˜5:2 R,R:R,S), which is purified General Purification Procedure C