Reaction Steps
A solution of 3% TCA (67.8 mL, 19.9 mmol) in CH2Cl2 is added to a solution of 8 (4.51 g, 4.97 mmol) dissolved in CH2Cl2 (100 mL) and stirred at room temperature for 4 minutes. Et3N (2.77 mL, 19.9 mmol) is added to the solution, and the solvent is removed under reduced pressure. The resulting solid is purified by column chromatography (silica, 90:10 CH2Cl2: EtOAc) to afford 9 as an off-white foam (2.56, 85.0%). 1H NMR (DMSO-d6) δ 10.69 (1H, s, N2H, exchanges with D2O), 8.47 (1H, s, H-8), 7.54 (2H, dd, J=8.4, J=1.6, PAc Ar), 7.42-7.34 (3H, m, Bn Ar), 7.31-7.26 (2H, m, Bn Ar), 6.97-6.92 (3H, m, PAc Ar), 6.33 (1H, t, J=6.8, H-1′), 5.63 (2H, s, CH2-Ph), 5.04 (2H, s, Pac-CH2), 4.94 (1H, t, J=5.4, 5′-OH, exchanges with D2O), 4.60 (1H, ddd, J=5.6, J=2.8, J=2.8, H-3′), 3.84 (1H, ddd, J=4.8, J=4.8, J=2.8, H-4′), 3.57 (1H, ddd, J=11.6, J=5.6, J=5.6, H-5′), 3.51 (1H, J=11.2, J=5.2, J=4.8, H-5′), 2.82 (1H, ddd, J=13.2, J=6.0, J=2.0, H-2′), 2.28 (1H, ddd, J=13.2, J=6.0, J=3.2, H-2′), 0.875 (9H, s, Si—C(CH3)3), 0.094 (3H, s, Si—CH3), 0.088 (3H, s, Si—CH3). Anal. (C31H39N5O6Si) C, H, N.
