反应详情

To a solution of 1,2,3,4,6-penta-O-acetyl-5-thio-D-glucopyranose (34.0 g, 0.0837 mol) in N,N-dimethylformamide (200 mL), a mixture of methylhydrazine (6.70 mL, 0.125 mmol), acetic acid (7.2 mL, 0.125 mol) and N,N-dimethylformamide (25 mL) was added under ice cooling. After stirring the raction mixture at room temperature for 2.5 hours, 0.5M HCl (300 mL) was added under ice cooling, and the resulting mixture was then extracted twice with ethyl acetate (250 mL). The combined organic phases were washed sequentially with water (200 mL), saturated aqueous NaHCO3 (100 mL), water (100 mL) and saturated aqueous sodium chloride (100 mL), followed by addition of MgSO4 and activated charcoal (1 g). After filtration to remove the insoluble materials, the filtrate was concentrated under reduced pressure. The resulting residue was crystallized from isopropyl ether (70 mL) to give 2,3,4,6-tetra-O-acetyl-5-thio-glucopyranose (26.9 g, 88%) as a colorless crystal.

1. additionwas added under ice cooling
2. extractionthe resulting mixture was then extracted twice with ethyl acetate (250 mL)
3. washThe combined organic phases were washed sequentially with water (200 mL), saturated aqueous NaHCO3 (100 mL), water (100 mL) and saturated aqueous sodium chloride (100 mL)
4. additionfollowed by addition of MgSO4 and activated charcoal (1 g)
5. filtrationAfter filtration
6. customto remove the insoluble materials
7. concentrationthe filtrate was concentrated under reduced pressure
8. customThe resulting residue was crystallized from isopropyl ether (70 mL)