p-Toluenesulfonic acid monohydrate → 5-Bromo-7-[2-(2,2-dimethyl-4-trifluoromethyl-[1,3]dioxolan-4-yl)-1,1-dimethylethyl]-2,3-dihydrobenzofuran

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Reaction Steps

A mixture of 7.6 g (20 mmol) of 4-(5-bromo-2,3-dihydrobenzofuran-7-yl)-4-methyl-2-trifluoromethylpentane-1,2-diol and 0.754 g (4 mmol) of p-toluenesulfonic acid monohydrate in 200 mL of acetone was stirred at room temperature for 6 days and the volatiles removed in vacuo. The residue was dissolved in EtOAc, washed with saturated aqueous sodium bicarbonate, dried over magnesium sulfate, and concentrated in vacuo. The residue was extracted with diethyl ether and the filtrate concentrated in vacuo to afford 6.3 g (75%) of 5-bromo-7-[2-(2,2-dimethyl-4-trifluoromethyl-[1,3]dioxolan-4-yl)-1,1-dimethylethyl]-2,3-dihydrobenzofuran.

Provenance & Evidence