反应详情

A mixture of 2,3,9,10-tetrafluoro-12-(2,3-di-O-benzyl-4-deoxy-β-D-glucopyranosyl)-6,7,12,13-tetrahydro(5H)indolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-dione (2.00 g, 2.76 mmol) and freshly activated, pulverized 4A molecular sieves (0.60 g) in 100 mL of dichloromethane was cooled at 5° C. under Ar and triethylamine (0.77 mL, 5.52 mmol), DMAP (0.20 g, 1.64 mmol) and methanesulfonyl chloride (0.32 mL, 4.14 mmol) were added sequentially. The mixture was stirred at the same temperature for 2 h and then it was filtered and the filter-cake was washed with ethyl acetate. The filtrate was diluted with ethyl acetate (200 mL) and ether (50 mL) and then it was washed (H2O ×2, brine), dried (MgSO4) and evaporated to give a yellow glass. This material was taken up in 100 mL of acetone, NaI ( ) was added and the mixture was heated to reflux under Ar for 18 h. The cooled mixture was then evaporated to dryness and the residue was taken up in 10 mL of ethyl acetate, washed (H2O ×2, brine) dried (MgSO4) and evaporated. The resulting solid was chromatographed (SiO2/2-32% ethyl acetate-hexane) to give 2,3,9,10-tetrafluoro-12-(2,3-di-O-benzyl-4-deoxy-6-iodo-β-D-glucopyranosyl)-6,7,12,13-tetrahydro(5H)indolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7-dione (0.90 g, 39%) as an amorphous yellow solid. To an ice-cold solution of this iodide (0.500 g, 0.60 mmol) in 20 mL of dry THF was added DBU (0.27 mL, 1.80 mmol) and the solution was kept at 5° C. for 2 h. The cooling bath was then removed and stirring was continued at room temperature for 16 h. Another portion of DBU (0.27 mL, 1.80 mmol) was then added and the reaction was allowed to continue for another 24 h. A further portion of DBU (0.27 mL, 1.80 mmol) was added and stirring was continued for an additional 24 h. The resulting mixture was diluted with ethyl acetate and then it was washed (1 N HCl ×2, H2O ×2, 1 M NaHCO3 ×2, H2O, brine), dried (MgSO4) and evaporated to give a gum. Flash chromatography (SiO2/2-16% ethyl acetate-hexane) afforded the title compound (0.297 g, 70%) as a yellow solid:

1. additionwere added sequentially
2. filtrationit was filtered
3. washthe filter-cake was washed with ethyl acetate
4. additionThe filtrate was diluted with ethyl acetate (200 mL) and ether (50 mL)
5. washit was washed (H2O ×2, brine)
6. dry with materialdried (MgSO4)
7. customevaporated
8. customto give a yellow glass
9. temperaturethe mixture was heated
10. temperatureto reflux under Ar for 18 h
11. customThe cooled mixture was then evaporated to dryness
12. washwashed (H2O ×2, brine)
13. dry with materialdried (MgSO4)
14. customevaporated
15. customThe resulting solid was chromatographed (SiO2/2-32% ethyl acetate-hexane)