反应 #1596944

反应方程式

ethanol

bismuth(III) bromide

4-benzyloxy-3-fluorobenzaldehyde

2-vinylpentan-1-ol

→

2-(4-benzyloxy-3-fluorophenyl)-4-bromo-5-propyltetrahydropyran

溶剂

chlorobutane

dichloromethane

反应条件

后处理

1. 1
   其他Insoluble constituents are separated off
2. 2
   过滤the mixture is filtered absorptively (SiO2, CH2Cl2)
3. 3
   浓缩The filtrate is concentrated to dryness
4. 4
   其他the residue is purified by column chromatography (SiO2, n-heptane:MTBE=4:1)
5. 5
   其他The oil obtained
6. 6
   其他The crystals which deposit are collected
7. 7
   其他recrystallised again from n-heptane

实验过程

188.0 g (0.79 mol) of 4-benzyloxy-3-fluorobenzaldehyde are initially introduced in 1000 ml of dichloromethane at 0° C. together with 90.0 g (0.79 mol) of 2-vinylpentan-1-ol. 176.0 g (0.39 mol) of bismuth(III) bromide are added in portions, and the mixture is stirred at room temperature for 19 h. Insoluble constituents are separated off, and the mixture is filtered absorptively (SiO2, CH2Cl2). The filtrate is concentrated to dryness, and the residue is purified by column chromatography (SiO2, n-heptane:MTBE=4:1). The oil obtained is taken up in chlorobutane, and the solution is added dropwise to cold ethanol. The crystals which deposit are collected and recrystallised again from n-heptane. In this way, 2-(4-benzyloxy-3-fluorophenyl)-4-bromo-5-propyltetrahydropyran is obtained as a yellowish solid.

来源