Reaction Steps
Compound 106 (0.5 g, 1.01 mmol) was dissolved in pyridine (10 ml) and acetic anhydride (0.20 ml, 2.12 mmol) was added under an argon atmosphere at room temperature. After being stirred for 24 hours at 20° C., the pyridine was removed in vacuo to give an oil. The oil was diluted with CH2Cl2 (20 ml) and washed with water (20 ml) and saturated NaHCO3 (20 ml). The organic layer was dried over anhydrous MgSO4 and the solvent was evaporated in vacuo to give a white foam. The foam was then purified by flash chromatography in EtOAc/Hexane (6:4) to give 183 (0.44 g, 81%) as a white foam. Tlc (Rf 0.80; EtOAc); 1H NMR (CDCl3): δ8.93 (br, 1 H, NH), 7.69-7.66 (m, 4 H, Ph), 7.48 (d, 1 H, J=1.1 Hz, H-6), 7.46-7.37 (m, 6 H, Ph), 6.17 (dd, 1 H, J=5.7, 6.7 Hz, H-1'), 4.09-4.05 (m, 3 H, H-5' & CH2 -OAc), 3.93-3.91 (m, 1 H, H-5'), 3.79 (dd 1 H, J=11.5, 3.2 Hz, H-5"), 2.80-2.78 (m, 1 H, H-3'), 2.33-2.21 (m, 1 H, H-2'), 2.19-2.16 (m, 1 H, H-2"), 2.03 (s, 3 H, COCH3), 1.62 (s, 3 H, CH3), 1.10 (s, 9 H, C(CH3)3); 13C NMR (CDCl3): δ170.7 (C=O), 163.7 (C4), 150.3 (C2), 135.5-135.2 (d), 133.0, 132.5, 130.1 (C6), 127.9-127.8 (d), 110.9 (C5), 84.7 (C1'), 82.9 (C4'), 64.4 (CH2 -OAc), 64.2 (C5'), 37.3 (C3'), 35.8 (C2'), 26.9, 20.8, 19.4, 12.1; Anal. Calcd for C29H36N2O6Si (536.699): C, 64.90; H, 6.76; N, 5.22. Found: C, 64.57; H 6.79; N, 5.12.
