Reacción #50760

Ecuación de reacción

1,2-dibromoethane

2-benzenesulphonyl-5-methoxytetrahydrofuran

Magnesium

4-bromoveratrole

→

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

Rendimiento 82.0%

Disolventes

THF

THF

THF

THF

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturawith warming
2. 2
   Otroreaction
3. 3
   TemperaturaThe resulting solution was heated
4. 4
   Temperaturaat reflux for 0.75 h
5. 5
   workup.STIRRINGto stir at room temperature for 20 h
6. 6
   OtroReaction
7. 7
   Otrowas quenched by addition of 1N HCl (50 ml)
8. 8
   Extracciónextracted with ether (2×100 ml)
9. 9
   LavadoThe organics were combined washed with water (50 ml)
10. 10
    Secadodried over anhydrous sodium sulphate
11. 11
    Filtraciónfiltered
12. 12
    Otroevaporated

Procedimiento

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).

Fuente