反应详情

温度

75 °C

To a suspension of 0.943 g (5 mmole) of 12 in 25 mL of ClCH2CH2 Cl, was added 1.25 mL (5 mmole) of BSA at 75° C. The reaction mixture was stirred at 75° C. for 30 min. To this solution, was added 1.75 g (5.5 mmole) of 1,2,3,5-tetra-O-acetyl-β-D-ribofuranose and 1.07 mL (5.5 mmole) of TMSOTf. Stirring was continued at 75° C. for 30 min. The reaction mixture was cooled to room temperature, diluted with 100 mL of CHCl3, and extracted with sat. NaHCO3 solution (100 mL×2) and sat. NaCl solution (100 mL). The CHCl3 phase was dried (Na2SO4) and evaporated. The residue was chromatographed on a silica column (3×25 cm, eluted successively with 0.5%, 1% MeOH/CHCl3). Evaporation of the appropriate fractions and recrystallization of the residue from MeOH gave 1.257 g (3 crops, 56%) of 64 as crystalline needles. MP 90°-91° C.; MS m/e 446.0694 (5%, M+ =446.0692); 1H NMR (DMSO-d6) d 7.93 (dd, 1, 7-H, 3JF-H =10.5 Hz, 4JF-H =7.5 Hz), 7.82 (dd, 1, 4-H, 3JF-H =10.5 Hz, 4JF-H =7.5 Hz), 6.23 (d, 1, 1'-H, J1'-2' =7.0 Hz), 5.55 (t, 1, 2'-H, J2'-3' =7.0 Hz), 5.44 (m, 1, 3'-H, J3-4 =4.5 Hz), 4.45 (m, 3, 4'-H and 5'-H), 2.13, 2.10, 2.02 (3×s, 9, 3×Ac); 13C NMR (DMSO-d6) d 169.95, 169.50, 169.18 (3×OCOCH3), 148.76, 148.62, 146.10, 145.93 (C5 and C6, 1JF-C =242 Hz), 140.16 (C2), 137.01 (C3a, 3JF-C =12 Hz), 128.54 (C7a, 3JF-C =12 Hz), 107.31, 107.09 (C4, JF-C =20 Hz), 100.93, 100.66 (C7, JF-C =24 Hz), 86.89 (Cl'), 79.41 (C4'), 70.40 (C2'), 68.62 (C3'), 62.67 (C5'), 20.43, 20.28, 20.00 (3×OCOCH3).

1. additionwas added 1.25 mL (5 mmole) of BSA at 75° C
2. stirringStirring
3. waitwas continued at 75° C. for 30 min
4. temperatureThe reaction mixture was cooled to room temperature
5. extractionextracted with sat. NaHCO3 solution (100 mL×2) and sat. NaCl solution (100 mL)
6. dry with materialThe CHCl3 phase was dried (Na2SO4)
7. customevaporated
8. customThe residue was chromatographed on a silica column (3×25 cm
9. washeluted successively with 0.5%, 1% MeOH/CHCl3)
10. customEvaporation of the appropriate fractions and recrystallization of the residue from MeOH