反应详情

To a solution of (1S,2S,3S,4R,5S)-5-(4-chloro-3-(4-ethoxybenzyl)phenyl)-1-(hydroxymethyl)-6,8-dioxabicyclo[3.2.1]octane-2,3,4-triol 28a (11.93 g, 27.3 mmol, purchased from Shanghai Caerulum Pharma Discovery Co., Ltd) in acetonitrile (40 mL) were added benzaldehyde dimethyl acetal (12.3 mL, 81.9 mmol) and p-toluenesulfonic acid monohydrate (4.7 g, 27.3 mmol) at room temperature. The mixture was stirred at room temperature for 30 min and adjusted with saturated aqueous sodium bicarnonate till pH becomes 7. The resulting mixture was extracted with ethyl actate (50 mL×2). The combined organic phases were washed with saturated aqueous sodium chloride (30 mL×2), dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated in vacuo and the residue was purified by silica gel chromatography eluted with PE/EtOAc(v/v)=5/1 to give the title compound 28b as a white solid (14.3 g, 100%).

1. extractionThe resulting mixture was extracted with ethyl actate (50 mL×2)
2. washThe combined organic phases were washed with saturated aqueous sodium chloride (30 mL×2)
3. dry with materialdried over anhydrous sodium sulfate
4. filtrationfiltered
5. concentrationThe filtrate was concentrated in vacuo
6. customthe residue was purified by silica gel chromatography
7. washeluted with PE/EtOAc(v/v)=5/1