反应详情

A solution of 7-bromo-5-methoxy-1,1-dimethyl-1,2,3,4-tetrahydro-naphthalene (Intermediate 63, 5.6 g, 20.81 mmol) in glacial acetic acid (20 mL) was cooled to 0° C. and treated with a solution of chromium trioxide (6.16 g, 61.6 mmol) in acetic acid and water (25 mL). The reaction mixture was then allowed to warm to ambient temperature and stirred for 48 h. It was diluted with water and extracted with diethyl ether (×2). The combined organic phase was washed with water (×3), saturated aqueous sodium bicarbonate (×1) and brine (×1), dried over anhydrous magnesium sulfate, filtered and evaporated in vacuo to afford an oil. Flash column chromatography over silica gel (230–400 mesh) using 10–20–100% ethyl acetate in hexane as the eluent afforded the title compound (2 g, 33%) as a yellow oil and recovered starting material (2.2 g, 39%).

1. extractionextracted with diethyl ether (×2)
2. washThe combined organic phase was washed with water (×3), saturated aqueous sodium bicarbonate (×1) and brine (×1)
3. dry with materialdried over anhydrous magnesium sulfate
4. filtrationfiltered
5. customevaporated in vacuo
6. customto afford an oil