反应 #1483130

反应方程式

ethyl bromoacetate

2-hydroxymethyl-3,4-dihydro-2H-pyran

NaH

hydrogen

sodium hydride

→

ethyl (3,4-dihydro-2H-pyran-2-ylmethoxy)acetate

收率 62.5%

溶剂

tetrahydrofuran

tetrahydrofuran

H2O

n-pentane

反应条件

后处理

1. 1
   温度After cooling
2. 2
   其他the solvent was evaporated under reduced pressure
3. 3
   其他The residue was purified by flash column chromatography (AcOEt:hexane=1:12) on silica gel (230-400 mesh)

实验过程

In a dried round bottomed flask under argon atmosphere, 60% sodium hydride (240 mg, 6.0 mmol) was rinsed three times with anhydrous n-pentane. A solution of 2-hydroxymethyl-3,4-dihydro-2H-pyran (570.8 mg, 5 mmol) in tetrahydrofuran (10 ml) was cooled at 0° C. and then added to the NaH. The reaction mixture was stirred at 0° C. until hydrogen evolution ended. A solution of ethyl bromoacetate (1253 mg, 7.5 mmol) in tetrahydrofuran (6 ml) was added to the reaction mixture and the stirring was continued at room temperature until disappearance of the starting alcohol (TLC analysis). After cooling, H2O was added, and the solvent was evaporated under reduced pressure. The residue was purified by flash column chromatography (AcOEt:hexane=1:12) on silica gel (230-400 mesh), affording 626 mg (yield 57%) of ethyl (3,4-dihydro-2H-pyran-2-ylmethoxy)acetate as a colorless oil; 1H NMR (401 MHz, DMSO-d6) δ ppm 1.18-1.23 (m, 3H) 3.55-3.59 (m, 2H) 3.93 (m, J=10.08, 5.11, 5.11, 2.38 Hz, 1H) 4.13 (q, J=7.07 Hz, 2H) 4.14 (s, 2H) 4.67 (dddd, J=6.14, 4.83, 2.56, 1.34 Hz, 1H) 6.36 (dt, J=6.13, 1.75 Hz, 1H).

来源