A solution of 12 (8.17 g. 35.4 mmol) in 200 mL anhydrous acetonitrile is treated with 1-O-acetyl-2,3,5-tri-O-benzoyl-D-ribofuranose (Pfanstiehl) at room temperature and under an atmosphere of argon. To this mixture is added TMS-triflate (6.11 mL, 35.4 mmol) and the mixture stirred at this temperature for 2 hr. Evaporation of the solvents in vacuo yielded an amber syrup which was immediately redissolved in 300 mL CH2Cl2, washed with cold, saturated NaHCO3 (2×150 mL), dried over magnesium sulfate, filtered and evaporated to a tan residue. Trituration of this residue with cold, anhydrous acetonitrile yielded analytically pure 13, 14.4 g (71%). 1H-NMR (DMSO-d6): δ 8.39 (d, 1 H, 6-H, J6,5 =11.8 Hz); 8.0-7.4 (m, 15 H, aromatic); 6.68 (d, 1 H, H-5); 6.11 (d, 1H, H-1', J1,2=2 Hz); 5.95 (m, 2 H, H-2',3'); 4.85 (m, 1 H, H-4'); 4.70 (m, 2 H, H-5',5"). Anal. Calcd for C30H23N2O8Cl: C, 62.67; H, 4.03; N, 4.87. Found: C, 62.21; H, 3.92; N, 4.80.
