反应详情

To a solution of nucleoside 1-(3-O-Benzyl-4-C-hydroxymethyl-β-D-xylofuranosyl)thymine 5 (5.38 g, 14.2 mmol) in anhydrous tetrahydrofuran (400 cm3) was added AgNO3 (2.66 g, 15.7 mmol) followed by anhydrous pyridine (5.7 cm3) and 4,4′-dimethoxytrityl chloride (5.30 g, 15.6 mmol). The mixture was stirred in the dark under nitrogen for 18 h at room temperature. The reaction was quenched by addition of a saturated aqueous solution of sodium hydrogen carbonate (10 cm3) and the resulting mixture was extracted with dichloromethane. The combined organic phase was evaporated to dryness under reduced pressure and the residue was co-evaporated with toluene and was purified by silica gel column chromatography using dichloromethane/methanol/pyridine (0.5% methanol; 0.5% pyridine, v/v) as eluent to afford nucleoside 6 (3.13 g, 31%) as a white foam after evaporation of the solvents. δC ((CD3)2SO) 164.1 (C-4), 158.4, 145.1, 138.5, 137.0, 135.9, 135.7, 130.1, 130.1, 129.2, 128.5, 128.5, 128.2, 128.1, 127.7, 127.6, 127.0, 125.7, 113.5 (DMT, benzyl, C-6), 151.4 (C-2), 110.1 (C-5), 85.8, 85.2, 84.6, 83.5 (C-1′, C-3′, C-4′, DMT), 76.8 (C-2′), 72.3 (CH2Ph), 65.2 (C-5″), 62.1 (C-5′), 55.4 (2× CH3O), 12.6 (5-CH3).

1. customThe reaction was quenched by addition of a saturated aqueous solution of sodium hydrogen carbonate (10 cm3)
2. extractionthe resulting mixture was extracted with dichloromethane
3. customThe combined organic phase was evaporated to dryness under reduced pressure
4. customwas purified by silica gel column chromatography