Trimethylsilyl triflate → (1S,3S,4R,7S)-3-(6-N-Benzoyladenin-9-yl)-7-benzyloxy-1-benzyloxymethyl-2,5-dioxabicyclo[2.2.1]heptane

Participants

Reaction Steps

A solution of furanose 207 (167 mg, 0.434 mmol) and 6-N-benzoyladenine (194 mg, 0.813 mmol) in anhydrous acetonitrile (5.3 mL) was added BSA (0.43 mL, 1.76 mmol) and stirred at room temperature for 1 h. The solution was cooled to 0° C. and trimethylsilyl triflate (0.16 mL, 0.86 mmol) was added dropwise. After stirring at 65° C. for 2 h, the reaction was quenched with a saturated aqueous solution of sodium hydrogen carbonate (40 mL) and the mixture was extracted with dichloromethane (2×50 mL). The combined extract was dried (MgSO4). The solvent was removed under reduced pressure and the residue was purified by chromatography over silica gel with dichloromethane:methanol (98:2) as eluent to give the product 208 as a solid (111 mg, 45%); 1H NMR (CDCl3): δ 8.82 (1H, s, H-8), 8.14 (1H, s, H-2), 7.59-7.26 (15H, m, Bz, Bn), 6.74 (1H, s, H-1′), 4.92 (1H, s, H-2′), 4.74-4.39 (4H, m, Bn), 4.42 (1H, s, H-3′), 4.19-4.10 (2H, m, H-5″), 3.92 (1H, d, J 11.8 Hz, H-5′), 3.88 (1H, d, J 11.5 Hz, H-5′); MS FAB: 564 (M+H, 100%).

Provenance & Evidence