反应 #87231

反应方程式

sodium bicarbonate

(3R,4R,5S)-4-hydroxy-5-methyl-3-phenethyldihydrofuran-2(3H)-one

2,6-dimethylpyridine

triisopropylsilyl trifluoromethanesulfonate

→

(3R,4R,5S)-5-methyl-3-phenethyl-4-((triisopropylsilyl)oxy)dihydro-furan-2(3H)-one

收率 59.2%

溶剂

CH2Cl2

反应条件

后处理

1. 1
   workup.ADDITIONmixed thoroughly
2. 2
   其他The phases were separated
3. 3
   萃取the aqueous extracted with CH2Cl2 (2×25 mL)
4. 4
   干燥The combined CH2Cl2 extracts were dried
5. 5
   浓缩concentrated to a colorless oil which
6. 6
   其他was purified by flash chromatography (SiO2, 0→50% EtOAc/hexanes)

实验过程

To a solution of (3R,4R,5S)-4-hydroxy-5-methyl-3-phenethyldihydrofuran-2(3H)-one (800 mg, 3.63 mmol) in CH2Cl2 (20 mL) were added 2,6-dimethylpyridine (592 μl, 5.08 mmol) and triisopropylsilyl trifluoromethanesulfonate (1171 μL, 4.36 mmol) at 0° C., and the mixture was warmed to room temperature while stirring overnight. The reaction mixture was poured onto 50 mL saturated sodium bicarbonate solution and mixed thoroughly. The phases were separated, and the aqueous extracted with CH2Cl2 (2×25 mL). The combined CH2Cl2 extracts were dried and concentrated to a colorless oil which was purified by flash chromatography (SiO2, 0→50% EtOAc/hexanes) to give (3R,4R,5S)-5-methyl-3-phenethyl-4-((triisopropylsilyl)oxy)dihydro-furan-2(3H)-one (809 mg, 53%): 1H NMR (400 MHz, CDCl3) δ 7.33-7.25 (m, 2H), 7.25-7.17 (m, 3H), 3.98 (dd, J=5.9, 4.8 Hz, 1H), 4.34-4.24 (m, 1H), 2.99-2.88 (m, 1H), 2.88-2.76 (m, 1H), 2.61-2.51 (m, 1H), 2.04-1.94 (m, 2H), 1.43 (d, J=6.5 Hz, 3H), 1.09-0.99 (m, 21H); 13C NMR (101 MHz, CDCl3) δ 176.64, 140.98, 128.57, 128.51, 126.16, 82.10, 79.45, 49.17, 32.96, 31.14, 19.10, 18.00, 17.71; ESIMS m/z 378 ([M+H]+).

来源