反应详情

To a solution of the starting nucleoside (40) (323 mg, 0.64 mmol) in THF (15 ml) under N2 protected atmosphere was added at room temperature tetrabutylammonium fluoride (TBAF) 1M in THF (0.7 ml, 0.7 mmol). Mixture stirred for one hour and then quenched by addition of H2O (5 ml). THF was evaporated and aqueous residue extracted into EtOAc (3×25 ml). Combined organic extracts were dried (MgSO4), filtered and the volatiles evaporated under reduced pressure giving a crude material which was purified by flash chromatography on a pre-packed silica column eluted with EtOAc. The product (41) was obtained as a white solid (233 mg, 93%). 1H NMR (d6 DMSO) δ 1.96-2.05 (m, 1H, H-2′) 2.24 (ddd, J=13.5, 5.8 and 2.8 Hz, 1H, H-2′), 3.50-3.62 (m, 2H, H5′), 3.91-3.97 (m, 2H, H3′, H4′), 4.03-4.07 (m, 2H, HHC—CH═), 5.11-5.16 (m, 2H, OH, CH═CHH), 5.24 (dd, J=17.2, 1.6 Hz, 1H, CH═CHH), 5.82-5.91 (m, 1H, CH═CHH), 6.02 (dd, J=7.6, 6.0 Hz, 1H, H-1′), 6.60 (s, 1H, NHH), 7.79 (s, 1H, NHH), 8.21 (s, 1H, H-6). MS (ES): m/z (%) (M−H) 392 (100%).

1. customquenched by addition of H2O (5 ml)
2. customTHF was evaporated
3. extractionaqueous residue extracted into EtOAc (3×25 ml)
4. dry with materialCombined organic extracts were dried (MgSO4)
5. filtrationfiltered
6. customthe volatiles evaporated under reduced pressure
7. customgiving a crude material which
8. customwas purified by flash chromatography on a pre-packed silica column
9. washeluted with EtOAc