反応 #50760

反応方程式

1,2-dibromoethane

2-benzenesulphonyl-5-methoxytetrahydrofuran

Magnesium

4-bromoveratrole

→

2-(3,4-dimethoxyphenyl)-5-methoxytetrahydrofuran

収率 82.0%

溶媒

THF

THF

THF

THF

反応条件

後処理

1. 1
   温度with warming
2. 2
   その他reaction
3. 3
   温度The resulting solution was heated
4. 4
   温度at reflux for 0.75 h
5. 5
   workup.STIRRINGto stir at room temperature for 20 h
6. 6
   その他Reaction
7. 7
   その他was quenched by addition of 1N HCl (50 ml)
8. 8
   抽出extracted with ether (2×100 ml)
9. 9
   洗浄The organics were combined washed with water (50 ml)
10. 10
    乾燥dried over anhydrous sodium sulphate
11. 11
    ろ過filtered
12. 12
    その他evaporated

実験手順

Magnesium (2.18 g, 0.091M) was placed in a 3-necked flask containing dry THF (10 ml) and 1,2-dibromoethane (0.2 ml). A solution of 4-bromoveratrole (18.0 g, 0.086M) in THF (50 ml) was added dropwise, with warming to initiate reaction. The resulting solution was heated at reflux for 0.75 h then cooled to room temperature and cannulated into a 1M solution of ZnBr2 in THF (50 ml, 0.05M) and stirred for 0.5 h at room temperature. A solution of 2-benzenesulphonyl-5-methoxytetrahydrofuran (10.0 g, 0.041M) in THF (50 ml) was added dropwise to the pale yellow suspension and the mixture allowed to stir at room temperature for 20 h. Reaction was quenched by addition of 1N HCl (50 ml), and extracted with ether (2×100 ml). The organics were combined washed with water (50 ml) dried over anhydrous sodium sulphate, filtered and evaporated. Column chromatography (flash silica gel; 3:2 hexane/ethyl acetate) gave 2-(3,4-dimethoxyphenyl)-5-methoxytetrahydrofuran (8.0 g, 82%) as a yellow oil (rf 0.28).

出典