反应详情

To a cold (˜−77° C., acetone/dry ice bath) solution of 19 (1.2 g, 2.87 mmol) in 50 ml of anhydrous dichloromethane was added via syringe 19 ml (19 mmol) of 1 M BCl3/CH2Cl2. The reaction was stirred for 10 hrs and quenched with a mixture of methanol (27 ml) and pyridine (13 ml). The reaction was warmed up, concentrated, co-evapoarated with a triethylamine/MeOH mixture to remove pyridine and chromatographed on C18 (5×25 cm) column eluting with a gradient of acetonitrile (0-15%). Concentration of the pure product fractions afforded 0.5 g (82%) of nucleoside 20 as a white solid. 1H NMR (DMSO-d6): δ 7.52 (d, J=7.2 Hz, 1H), 7.01 (br s, 2H), 5.65 (d, J=7.2 Hz), 4.70 (d, J=4.8 Hz, 1H), 4.62 (t, J=5.4 Hz, 1H), 3.84 (m, 1H), 3.63 (m, 2H), 3.34 (m, 1H), 3.25 (m, 1H), 1.68 (m, 1H), 1.08 (d, J=6.3 Hz, 3H).

1. customquenched with a mixture of methanol (27 ml) and pyridine (13 ml)
2. temperatureThe reaction was warmed up
3. concentrationconcentrated, co-evapoarated with a triethylamine/MeOH mixture
4. customto remove pyridine
5. customchromatographed on C18 (5×25 cm) column
6. washeluting with a gradient of acetonitrile (0-15%)