反应 #162915

反应方程式

(3R,4R,5S)-3-benzyl-5-methyl-4-(triisopropylsilyloxy)-dihydrofuran-2(3H)-one

dry ice acetone

diisobutylaluminum hydride

hexane

→

(2S,3R,4S)-2-benzyl-3-(triisopropylsilyloxy)pentane-1,4-diol

收率 71.2%

溶剂

CH2Cl2

反应条件

后处理

1. 1
   其他The resulting colorless solution was removed from the cold bath
2. 2
   温度cooled to 0° C. (ice water bath)
3. 3
   其他quenched with sat'd aqueous Rochelle's salt solution (200 mL) and Et2O (200 mL)
4. 4
   workup.STIRRINGThe resulting slurry was stirred vigorously until the mixture
5. 5
   其他biphasic (1.5 h) and the resulting phases were separated
6. 6
   萃取The aqueous phase was extracted with Et2O (2×200 mL)
7. 7
   干燥The combined organic phases were dried over MgSO4
8. 8
   过滤filtered
9. 9
   浓缩concentrated
10. 10
    其他to provide an oil
11. 11
    其他Purification by automated silica gel column chromatography (0-20% acetone in hexanes)

实验过程

To a solution of (3R,4R,5S)-3-benzyl-5-methyl-4-(triisopropylsilyloxy)-dihydrofuran-2(3H)-one (9.42 g, 26.0 mmol, 1.00 equiv) in CH2Cl2 (130 mL, 0.2 M) at −78° C. (dry ice/acetone bath) was added a 1 M solution of diisobutylaluminum hydride in hexane (DIBAL-H, 65.0 mL, 65.0 mmol, 2.50 equiv). The resulting colorless solution was removed from the cold bath and stirred at 23° C. for 18 h, cooled to 0° C. (ice water bath), and quenched with sat'd aqueous Rochelle's salt solution (200 mL) and Et2O (200 mL). The resulting slurry was stirred vigorously until the mixture became clear and biphasic (1.5 h) and the resulting phases were separated. The aqueous phase was extracted with Et2O (2×200 mL). The combined organic phases were dried over MgSO4, filtered, and concentrated to provide an oil. Purification by automated silica gel column chromatography (0-20% acetone in hexanes) provided (2S,3R,4S)-2-benzyl-3-(triisopropylsilyloxy)pentane-1,4-diol (6.78 g, 71.2%) as a white solid: 1H NMR (400 MHz, CDCl3) δ 7.35-7.08 (m, 5H), 4.11-3.96 (m, 1H), 3.95-3.77 (m, 2H), 3.57-3.40 (m, 1H), 3.09 (d, J=2.5 Hz, 2H), 2.93-2.76 (m, 2H), 2.04 (dd, J=5.7, 2.9 Hz, 1H), 1.35 (d, J=6.6 Hz, 3H), 1.12 (d, J =3.6 Hz, 1H), 1.05 (s, 20H); 13C NMR (101 MHz, CDCl3) δ 141.12, 129.10, 128.42, 125.98, 71.23, 59.84, 48.58, 34.81, 19.10, 18.18, 12.72; ESIMS m/z 365.3 ([M−H]−).

来源