反应详情

To a mixture of #11 (4.09 g, 14.2 mmol, 1 eq.) in cyclopentyl methyl ether (10 mL, 0.14 M) was added a 4 N solution of hydrogen chloride in dioxane (37 mL, 100 mmol, 7 eq.). After three hours, the reaction mixture was concentrated in vacuo and azeotroped three times with heptane to give #103 (1000 mg, 31%) as a gum, which was used in the next step without further purification. 1H NMR (400 MHz, DMSO-d6) δ 9.92-10.06 (br s, 1H), 8.66-8.80 (br s, 1H), 3.89 (dd, J=5.2, 4.9 Hz, 1H), 3.43-3.53 (m, 1H), 3.39 (s, 3H), 3.06-3.17 (m, 2H), 2.66 (qd, J=7.1, 4.6 Hz, 1H), 1.71-2.03 (m, 4H), 1.11 (d, J=7.1 Hz, 3H).

1. concentrationthe reaction mixture was concentrated in vacuo
2. customazeotroped three times with heptane