Reaktion #487464

Reaktionsgleichung

2,2,6,6-Tetramethylbenzo[1,2-d:4,5-d']-(1,3)dioxole

2,2,6,6-Tetramethylbenzo[1,2-d:4,5-d']bis(1,3)dioxole

diethyl ether

n-Butyl lithium

methyl magnesium bromide

→

8-hydroxy-2,2,6,6-tetramethyl-benzo[1,2-d:4,5-d']bis(1,3)dioxole

Ausbeute 28.0%

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeOxygen was bubbled through the solution over a period of 2 hours
2. 2
   Temperaturwhile cooling with a cold water bath
3. 3
   workup.ADDITIONThe reaction mixture was poured into a solution of NaOH (50 mL, 1M)
4. 4
   Extraktionextracted with diethyl ether (100 mL)
5. 5
   workup.STIRRINGwhile stirring
6. 6
   SonstigeThe product was isolated
7. 7
   Extraktionby extracting with diethyl ether (3×50 mL)
8. 8
   TrocknenThe ether was dried (Na2SO4)
9. 9
   Sonstigeevaporated

Vorschrift

2,2,6,6-Tetramethylbenzo[1,2-d:4,5-d']-(1,3)dioxole (5.00 g, 22.5 mmol (Example 5)) was dissolved in diethyl ether (150 mL, sodium benzophenone ketyl) under argon. n-Butyl lithium (10.0 mL, 25 mmol, 2.5M in toluene) was added at room temperature followed by methyl magnesium bromide (4.25 mL, 13 mmol, 3.0M in diethyl ether, Aldrich). the resulting mixture was stirred at room temperature for 1 h. Oxygen was bubbled through the solution over a period of 2 hours, while cooling with a cold water bath. The reaction mixture was poured into a solution of NaOH (50 mL, 1M) and extracted with diethyl ether (100 mL). The aqueous phase was acidified with conc. HCl to pH 2 while stirring. The product was isolated by extracting with diethyl ether (3×50 mL). The ether was dried (Na2SO4) and evaporated yielding 1.50 g (6.3 mmol, 28%) of 8-hydroxy-2,2,6,6-tetramethyl-benzo[1,2-d:4,5-d']bis(1,3)dioxole.

Quelle