反应详情

A solution of dimethyl bicyclo[2.2.2]octane-1,4-dicarboxylate (58.0 g, 0.25 mol) in methanol (600 mL) was heated to reflux and then a solution of potassium hydroxide (9.8 g, 0.175 mol) in methanol (100 mL) and water (12 mL) was added over 30 min. The reaction mixture was refluxed for 24 h and concentrated. The residue was diluted with water and extracted with ethyl acetate (200 mL×2) to recover some starting material (22.0 g). The resulting aqueous layer was acidified to pH=3 by addition of hydrochloric acid and extracted with ethyl acetate (300 mL×3). The combined organic layers were washed with brine, dried over sodium sulfate and concentrated to give the titled product (30.0 g, 0.14 mol, yield 55%). 1H NMR (400 MHz, CDCl3) δ ppm 3.65 (s, 3H), 1.81 (s. 12H); MS (ESI) m/z=211.3 [M+H]−.

1. temperatureto reflux
2. temperatureThe reaction mixture was refluxed for 24 h
3. concentrationconcentrated
4. additionThe residue was diluted with water
5. extractionextracted with ethyl acetate (200 mL×2)
6. customto recover some starting material (22.0 g)
7. additionThe resulting aqueous layer was acidified to pH=3 by addition of hydrochloric acid
8. extractionextracted with ethyl acetate (300 mL×3)
9. washThe combined organic layers were washed with brine
10. dry with materialdried over sodium sulfate
11. concentrationconcentrated