Sodium Carbonate → chloromethyl (2S)-2-(((tert-butoxy)carbonyl)amino)-3-methylbutanoate

Participants

Reaction Steps

To a stirred solution of (S)-2-((tert-butoxycarbonyl)amino)-3-methylbutanoic acid (1 g, 4.60 mmol), sodium carbonate (2.439 g, 23.01 mmol) and tetrabutylammonium hydrogen sulfate (0.313 g, 0.921 mmol) in a mixture of DCM (10 mL) and water (5 mL) at 0° C., was added chloromethyl chlorosulfate (1.519 g, 9.21 mmol). The reaction mixture was allowed to warm to room temperature overnight. The mixture was diluted with DCM and water, and the organic layer was separated, washed with a brine solution, and dried over Na2SO4. The solution was filtered and concentrated in vacuo and the residue obtained was purified by a flash chromatography (SiO2, 0-10% EtOAc in hexane) to afford Preparation 52A (0.9 g, 73.6%) as a colorless oil. 1H NMR (400 MHz, CDCl3) δ 0.93 (d, J=6.80 Hz, 3H), 1.00 (d, J=6.80 Hz, 3H), 1.43 (s, 9H), 2.17-2.18 (m, 1H), 4.25-4.27 (m, 1H), 4.96 (d, J=7.60 Hz, 1H), 5.62 (d, J=6.00 Hz, 1H), 5.88 (d, J=6.00 Hz, 1H).

Provenance & Evidence