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

Participants

Reaction Steps

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.

Provenance & Evidence