反应详情

温度

-10 °C

To a solution of dry pyridine (0.46 mL) in methylene chloride (17.5 mL) cooled to -15° C. was added trifluoromethanesulfonic anhydride (0.87 mL). The mixture was stirred during 15 min at -10° C., then methyl 2,3,4-tri-O-benzyl-α-D-glucopyranoside (1.2 g, 2.58 mmol) in methylene chloride (5 mL) was added [P. Kovac, V. Sklenar and C. Glaudemans, Carbohydr. Res. 175, 201 (1988)]. The mixture was stirred during 1.5 h at -10° C. The reaction mixture was washed with water. The organic layer was dried over sodium sulfate, filtered and concentrated under reduced pressure to afford an oil. Flash chromatography on silica gel and elution with a 7:3 mixture of hexane and ethyl acetate afforded the expected compound methyl 2,3,4-tri-O-benzyl-6-O-trifluoromethylsulfonyl-α-D-glucopyranoside which was crystallized from hexane (1.43 g, 93%); m.p. 44°-45° C.

1. stirringThe mixture was stirred during 1.5 h at -10° C
2. washThe reaction mixture was washed with water
3. dry with materialThe organic layer was dried over sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated under reduced pressure
6. customto afford an oil
7. washFlash chromatography on silica gel and elution
8. additionwith a 7:3 mixture of hexane and ethyl acetate