反应详情

To a flask containing compound 4a (50 mg, 0.0618 mmol) at 0-5° C. was added dropwise 4M HCl (g) in 1,4-dioxane (3 mL) over 10 min. The resulting mixture was gradually warmed to room temperature and continuously stirred for 40 h. Ether (20 mL) was added to the reaction mixture which was then stirred for 10 min. The resulting precipitate was filtered and washed with ether. The solid product was quickly dissolved in deionized water. The aqueous solution was concentrated in vacuo to provide 5a (40 mg, 100%) as an off-white solid. 1H NMR (D2O, 300 MHz) δ 2.63-2.82 (m, 1H), 2.96-3.40 (m, 7H), 3.40-4.05 (m, 11H), 7.39 (d, J=8.1 Hz, 2H), 8.09 (d, J=7.8 Hz, 2H); 13C NMR (D2O, 300 MHz) δ 32.7 (t), 50.2 (t), 50.7 (t), 52.5 (t), 54.0 (t), 54.9 (t), 55.3 (t), 61.1 (d), 124.1 (d), 130.3 (d), 144.5 (s), 146.8 (s), 170.4 (s), 170.9 (s), 173.5 (s).

1. stirringwas then stirred for 10 min
2. filtrationThe resulting precipitate was filtered
3. washwashed with ether
4. dissolutionThe solid product was quickly dissolved in deionized water
5. concentrationThe aqueous solution was concentrated in vacuo