反应详情

To a stirred solution of the product from Example 17.1 (1.718 g, 3.53 mmol) in diethyl ether (30 ml) was added methanol (1.43 ml, 35.3 mmol) and then lithium borohydride (8.83 ml, 17.7 mmol, 2.0M in THF). After 1 h methanol (1.43 ml, 35.3 mmol) was added to the reaction mixture and stirring continued. After 1 h further the reaction mixture was diluted with methanol and then concentrated. The residue was dissolved in methanol (20 ml), diluted with hydrochloric acid (20 ml, 1M) and concentrated. The residue was chromatographed on silica gel (methanol [7N ammonia]-DCM, 15:85) giving a white solid (0.940 g, 66%). 1H NMR (CD3OD) δ 8.43 (s, 1H), 7.69 (s, 1H), 7.28-7.15 (m, 5H), 5.77 (s, 2H), 4.52 (s, 2H), 4.12 (ABq, 2H), 4.11 (s, 31-1), 3.80 (dd, J=11.7, 5.3 Hz, 1H), 3.80-3.60 (m, 3H), 3.59 (dd, J=11.0, 4.9 Hz, 1H), 2.90 (q, J=4.9 Hz, 1H). 13C NMR (CD3OD) δ 158.4, 151.4, 151.0, 139.1, 135.0, 129.7, 129.2, 129.1, 117.5, 115.3, 79.0, 72.5, 72.0, 65.6, 62.0, 61.6, 54.8, 42.1.

1. concentrationconcentrated
2. dissolutionThe residue was dissolved in methanol (20 ml)
3. additiondiluted with hydrochloric acid (20 ml, 1M)
4. concentrationconcentrated
5. customThe residue was chromatographed on silica gel (methanol [7N ammonia]-DCM, 15:85)