Boc-D-alanine methyl ester → tert-butyl N-((2R)-1-oxopropan-2-yl)carbamate

Participants

Reaction Conditions

Reaction Steps

To a cooled solution of (R)-methyl 2-(tert-butoxycarbonylamino)propanoate (40.0 g, 98.0 mmol) in DCM (200 mL) at −78° C. was added diisobutylaluminum hydride (208 mL, 1.0 M in THF) dropwise over 30 min. The reaction mixture was stirred at −78° C. for 1.5 h then quenched with water (50 mL). After warmed to rt, the white precipitate was removed by filtration over Celite. The organic layer was then washed with brine, dried (Na2SO4), and concentrated. The crude residue was purified by flash chromatography (petroleum ether:EtOAc, 10:1) to give (R)-tert-butyl 1-oxopropan-2-ylcarbamate (28.0 g, 82%). 1H NMR (DMSO-d6, 400 MHz) δ 9.43 (s, 1H), 7.33 (d, J=6.0 Hz, 1H), 3.85 (m, 1H), 1.39 (s, 9H), 1.12 (d, J=7.2 Hz, 3H).

Provenance & Evidence