反应详情

温度

60 °C

To a stirred suspension of the anomeric mixture 14 (4.50 g, 8.21 mmol) and thymine (1.55 g, 12.31 mmol) in anhydrous acetonitrile (50 cm3) was added N,O-bis(trimethylsilyl)-acetamide (12.2 cm3, 49.3 mmol). The reaction mixture was stirred at 60° C. for 1 h and then cooled to 0° C. Trimethylsilyl triflate (2.97 cm3, 16.4 mmol) was added dropwise during 10 min and the mixture was heated for 2 h under reflux. The reaction mixture was allowed to cool to room temperature and the volume was reduced by 50% under reduced pressure. After cooling to 0° C., a saturated aqueous solution of sodium hydrogen carbonate (100 cm3) was added and extraction was performed with dichloromethane (2×50 cm3). The combined organic phase was washed with brine (50 cm3), dried (Na2SO4) and evaporated to dryness under reduced pressure. The residue was purified by silica gel column chromatography using dichloromethane/methanol (99.5:0.5, v/v) as eluent to give nucleoside 15 as white solid material (4.06 g, 81%) after evaporation of the solvents under reduced pressure.

1. temperaturecooled to 0° C
2. temperaturethe mixture was heated for 2 h
3. temperatureunder reflux
4. temperatureto cool to room temperature
5. temperatureAfter cooling to 0° C.
6. extractionextraction
7. washThe combined organic phase was washed with brine (50 cm3)
8. dry with materialdried (Na2SO4)
9. customevaporated to dryness under reduced pressure
10. customThe residue was purified by silica gel column chromatography