Reaktion #50766

Reaktionsgleichung

2-benzenesulphonyl-5-methoxytetrahydrofuran

n-butyllithium

hexane

1-bromo-3,4,5-trimethoxybenzene

magnesium(II) bromide

→

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

Ausbeute 27.3%

Lösungsmittel

THF

THF

THF

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigesonicated for 0.4 h
2. 2
   Sonstigesonicated for 1 h
3. 3
   workup.STIRRINGstirred overnight
4. 4
   SonstigeThe reaction was quenched by the addition of aqueous ammonium chloride (20 ml)
5. 5
   Sonstigepurification

Vorschrift

To stirred solution of 1-bromo-3,4,5-trimethoxybenzene (2.47 g, 10 mmol) in THF (20 ml) at -78° C. was added 2.5M n-butyllithium in hexane (4.4 ml, 11 mmol). After 0.75 h the solution was cannulated into a mixture of 1M zinc(II) bromide in THF (11 ml, 11 mmol) and magnesium(II) bromide etherate (2.86 g, 15 mmol) in THF (10 ml) at -78° C. The resulting mixture was allowed to warm to room temperature over 1 h and then sonicated for 0.4 h. A solution of 2-benzenesulphonyl-5-methoxytetrahydrofuran (1.85 g, 7.5 mmol) in THF (10 ml)was added and the mixture stirred at room temperature for 1 h, sonicated for 1 h and stirred overnight. The reaction was quenched by the addition of aqueous ammonium chloride (20 ml). Work up and purification as described for Example 1(b) gave 2-(3,4,5-trimethoxyphenyl)-5 -methoxytetrahydrofuran (0.55 g, 27%) as a colourless oil.

Quelle