Реакция #87232

Уравнение реакции

(3R,4R,5S)-5-methyl-3-phenethyl-4-((triisopropyl-silyl)oxy)dihydrofuran-2(3H)-one

DIBAL-H

→

(2S,3R,4S)-2-phenethyl-3-((triisopropylsilyl)oxy)pentane-1,4-diol

Выход 69.2%

Растворители

CH2Cl2

Условия реакции

Обработка

1. 1
   ДругоеThe dry ice/acetone bath was removed
2. 2
   Температураto warm to room temperature
3. 3
   ТемператураThe reaction was cooled to 0° C.
4. 4
   Другоеquenched by addition of saturated potassium sodium tartrate solution (50 mL)
5. 5
   workup.ADDITIONThe mixture was diluted with CH2Cl2 (25 mL)
6. 6
   workup.STIRRINGstirred until two clean-splitting phases
7. 7
   Другоеwere formed
8. 8
   ДругоеThe phases were separated
9. 9
   Экстракцияthe aqueous extracted further with CH2Cl2
10. 10
    ДругоеThe combined organic extracts were dried
11. 11
    Концентрированиеconcentrated to a colorless oil which
12. 12
    Другоеwas purified by flash chromatography (SiO2, 030% EtOAc/hexanes)

Методика

To an oven-dried flask were added (3R,4R,5S)-5-methyl-3-phenethyl-4-((triisopropyl-silyl)oxy)dihydrofuran-2(3H)-one (670 mg, 1.601 mmol) and CH2Cl2 (8 mL)) and the mixture was cooled to −78° C. and treated with DIBAL-H (1.0 M in CH2Cl2, 4.00 mL, 4.00 mmol) dropwise over 10 min. The dry ice/acetone bath was removed and the mixture allowed to warm to room temperature while stirring overnight. The reaction was cooled to 0° C. and quenched by addition of saturated potassium sodium tartrate solution (50 mL). The mixture was diluted with CH2Cl2 (25 mL) and stirred until two clean-splitting phases were formed. The phases were separated, and the aqueous extracted further with CH2Cl2. The combined organic extracts were dried and concentrated to a colorless oil which was purified by flash chromatography (SiO2, 030% EtOAc/hexanes) to give (2S,3R,4S)-2-phenethyl-3-((triisopropylsilyl)oxy)pentane-1,4-diol (422 mg, 69%): 1H NMR (400 MHz, CDCl3) δ 7.30-7.23 (m, 2H), 7.21-7.14 (m, 3H), 4.02-3.92 (m, 2H), 3.77 (dd, J=4.3, 3.1 Hz, 1H), 3.72-3.61 (m, 1H), 3.18 (s, 1H), 2.92-2.76 (m, 2H), 2.62-2.51 (m, 1H), 2.10-1.96 (m, 1H), 1.80-1.62 (m, 2H), 1.27 (d, J=6.7 Hz, 3H), 1.07-0.93 (m, 21H); 13C NMR (101 MHz, CDCl3) δ 141.94, 128.48, 128.36, 125.86, 78.18, 71.24, 59.48, 45.39, 34.24, 29.69, 18.64, 18.14, 18.10, 12.54; ESIMS m/z 403 ([M+Na]+).

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