反应详情

温度

-15 °C

To a mixture of (S)-2-(tert-butoxycarbonylamino)-3-methoxypropanoic acid (10.9 g) and N-methylmorpholine (5.6 g, 55 mmol) in THF (50 mL) was added 2-methylpropylchloroformate (7.48 g, 55 mmol) in THF at −15° C. The reaction mixture was stirred −15° C. for 15 min, after which NaBH4 (6.0 g, 159 mmol) in water (10 mL) was added. The reaction mixture was stirred for 30 min, then diluted with EtOAc, and neutralized with dilute HCl. The organic layer was dried over Na2SO4 and concentrated. The residue was purified by column chromatography on silica gel eluting with EtOAc and petroleum ether (EtOAc/PE=1.5/1) to give the title compound (6.0 g, 58%). 1H NMR (400 MHz, CDCl3) δ ppm 5.23 (s, 1 H), 3.80 (d, J=8.0 Hz, 2 H), 3.72-3.68 (m, 1 H), 3.60-3.52 (m, 2 H), 3.38 (s, 3 H), 2.85 (s, 1 H), 1.47 (s, 9H).

1. stirringThe reaction mixture was stirred for 30 min
2. dry with materialThe organic layer was dried over Na2SO4
3. concentrationconcentrated
4. customThe residue was purified by column chromatography on silica gel eluting with EtOAc and petroleum ether (EtOAc/PE=1.5/1)