Reaction Steps
To a solution of compound 49 (130 mg, 0.18 mmol) in THF (10 mL), n-Bu4NF (141 mg, 0.44 mmol) was added. The mixture was stirred at room temperature for four hours, concentrated in vacuo, and the residue was purified by silica gel column chromatography to yield 5-[(S)-1-(5-methoxy-2-nitrophenyl)-2,2-dimethyl-propyloxy]methyl-2′-deoxycytidine 50 (72 mg, 82%). 1H NMR (400 MHz, DMSO-d6): δ 7.99 (d, J=8.0 Hz, 1H, Ph-H), 7.65 (s, 1H, H-6), 7.42 (br s, 1H, D2O exchangeable, NH2a), 7.06 (m, 2H, Ph-H), 6.72 (br s, 1H, D2O exchangeable, NH2b), 6.11 (t, 1H, J=6.4 Hz, H-1′), 5.17 (d, 1H, D2O exchangeable, 3′-OH), 5.12 (s, 1H, Ph-CH), 4.78 (t, 1H, D2O exchangeable, 5′-OH), 4.25 (d, 1H, J=12.4 Hz, 5-CH2a), 4.15 (m, 1H, H-3′), 4.05 (d, 1H, J=12.4 Hz, 5-CH2b), 3.87 (s, 3H, OCH3), 3.72 (m, 1H, H-4′), 3.44 (m, 2H, H-5′), 3.76 (dd, 1H, J=2.8 Hz, H-5′b), 2.08 (m, 1H, H-2′a), 1.95 (m, 1H, H-2′b), 0.77 (s, 9H, C(CH3)3).
