反应详情

To a suspension of lithium aluminum hydride (2.94 g, 78 mmol) in 50 mL diethyl ether at 0° C. was slowly added a solution of (2S,3R)-3-(benzyloxy)-2-((tert-butoxycarbonyl)amino)butanoic acid (8.0 g, 25.9 mmol) in 25 mL diethyl ether. The reaction was allowed to warm to rt and stirred 1 hr. Water (3 ml) was added with caution, to the reaction mixture. This addition was followed by an addition of 15% NaOH (3 ml) and water (9 ml). These additions were made with extreme caution to control the rate of gas evolution. After stirring 1 hr at rt, MgSO4 was added and the mixture was filtered. The filtrate was concentrated to afford an oil, which was chromatographed on a 120 gm Isco cartridge using an 0-75% EtOAc/Hex gradient. The pure fractions were concentrated to afford tert-butyl((2R,3R)-3-(benzyloxy)-1-hydroxybutan-2-yl)carbamate (5.44 g, 18.42 mmol, 71.2% yield) as a colorless oil. 1H NMR (400 MHz, CCl3D) δ 7.32 (s, 5H), 5.07 (br. s., 1H), 4.64 (d, J=11.4 Hz, 1H), 4.38 (d, J=11.7 Hz, 1H), 3.83 (d, J=6.2 Hz, 1H), 3.79-3.71 (m, 1H), 3.70-3.59 (m, 2H), 2.60-2.38 (m, 1H), 1.48-1.42 (m, 9H), 1.27-1.25 (m, 3H).

1. additionThis addition
2. stirringAfter stirring 1 hr at rt
3. filtrationthe mixture was filtered
4. concentrationThe filtrate was concentrated
5. customto afford an oil, which
6. customwas chromatographed on a 120 gm Isco cartridge
7. concentrationThe pure fractions were concentrated