L-Valine → N-(Methoxycarbonyl)-D-valine

Participants

Reaction Conditions

Reaction Steps

To a mixture of L-valine (220 mg, 1.9 mmol) and NaHCO3 (482 mg, 5.6 mmol) in H2O (6 mL) at 0° C. is added dropwise methylchloroformate (0.25 mL, 3.25 mmol). The reaction mixture is stirred for 2 hours at 0-5° C. The mixture is diluted with water and washed with Et2O. The aqueous layer is acidified with 1N HCl to pH 3 and the product is extracted with EtOAc. The combined organic layers are washed with brine, dried over sodium sulfate and concentrated in vacuum. The residue is triturated with hexanes-Et2O to give (R)-2-methoxycarbonylamino-3-methyl-butyric acid (248 mg, 75%).

Provenance & Evidence