反应详情

A solution of Example 11B (8.5 g, 32.5 mmol) in acetone (200 mL) was treated with water (100 mL) and p-toluenesulfonic acid monohydrate (1 g), heated to reflux, stirred overnight, and concentrated to remove the acetone. The remaining aqueous solution was extracted with ethyl acetate (3×100 mL) and the combined extracts were washed sequentially with 1N NaOH, water, and brine, dried (Na2SO4), filtered, and concentrated to provide the desired product (6.95 g, 95%). MS (CI) m/e 236.2 (M+18)+.

1. temperatureheated
2. temperatureto reflux
3. concentrationconcentrated
4. customto remove the acetone
5. extractionThe remaining aqueous solution was extracted with ethyl acetate (3×100 mL)
6. washthe combined extracts were washed sequentially with 1N NaOH, water, and brine
7. dry with materialdried (Na2SO4)
8. filtrationfiltered
9. concentrationconcentrated