反応 #1596944

反応方程式

ethanol

bismuth(III) bromide

4-benzyloxy-3-fluorobenzaldehyde

2-vinylpentan-1-ol

→

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

溶媒

chlorobutane

dichloromethane

反応条件

後処理

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

実験手順

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.

出典