反应 #1747883

反应方程式

methyl ester

(4R)-4-tert-Butoxycarbonylamino-5-methyl-3-oxohexanoic Acid Methyl Ester

potassium borohydride

→

alcohol

(3S,4R)-4-tert-Butoxycarbonylamino-3-hydroxy-5-methylhexanoic Acid Methyl Ester

溶剂

MeOH

反应条件

后处理

1. 1
   温度warmed to −20° C. for 30 min
2. 2
   workup.WAITto 0° C. for 10 min
3. 3
   其他The reaction was quenched with acetic acid to pH=7
4. 4
   萃取extracted with CH2Cl2 (3×50 mL)
5. 5
   洗涤The organic layer was washed with NaHCO3 (50 mL, sat), NaCl (50 mL, sat)
6. 6
   干燥dried (Na2SO4)
7. 7
   过滤filtered
8. 8
   其他evaporated

实验过程

To a solution of methyl ester 45 (2.4 g, 8.70 mmol) in HPLC MeOH (100 mL), cooled to −78° C., potassium borohydride (1.4 g, 26.1 mmol) was added in portions. The reaction mixture was stirred at −78° C. for 10 min, warmed to −20° C. for 30 min and then to 0° C. for 10 min. The reaction was quenched with acetic acid to pH=7 and extracted with CH2Cl2 (3×50 mL). The organic layer was washed with NaHCO3 (50 mL, sat), NaCl (50 mL, sat), dried (Na2SO4), filtered, and evaporated. The alcohol 46 was obtained as a colorless oil (2.2 g, 92%) and used directly in the next step. 1H-NMR (500 MHz, CDCl3): 0.88 (d, J=6.8 Hz, 3H), 0.93 (d, J=6.8 Hz, 3H), 1.44 (s, 9H), 2.03-2.17 (m, 1H), 2.41-2.52 (m, 1H), 2.58-2.63 (m, 1H), 3.50-3.55 (m, 1H), 3.71 (s, 3H), 3.89-3.93 (m, 1H), 3.38-3.41 (m, 1H).

来源