반응 #1596944

반응 방정식

ethanol

bismuth(III) bromide

4-benzyloxy-3-fluorobenzaldehyde

2-vinylpentan-1-ol

→

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

용매

chlorobutane

dichloromethane

반응 조건

후처리

1. 1
   기타Insoluble constituents are separated off
2. 2
   여과the mixture is filtered absorptively (SiO2, CH2Cl2)
3. 3
   농축The filtrate is concentrated to dryness
4. 4
   기타the residue is purified by column chromatography (SiO2, n-heptane:MTBE=4:1)
5. 5
   기타The oil obtained
6. 6
   기타The crystals which deposit are collected
7. 7
   기타recrystallised again from n-heptane

실험 절차

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.

출처