Реакция #1596944

Уравнение реакции

ethanol

bismuth(III) bromide

4-benzyloxy-3-fluorobenzaldehyde

2-vinylpentan-1-ol

→

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

Растворители

chlorobutane

dichloromethane

Условия реакции

Обработка

1. 1
   ДругоеInsoluble constituents are separated off
2. 2
   Фильтрацияthe mixture is filtered absorptively (SiO2, CH2Cl2)
3. 3
   КонцентрированиеThe filtrate is concentrated to dryness
4. 4
   Другоеthe residue is purified by column chromatography (SiO2, n-heptane:MTBE=4:1)
5. 5
   ДругоеThe oil obtained
6. 6
   ДругоеThe crystals which deposit are collected
7. 7
   Другоеrecrystallised again from n-heptane

Методика

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.

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