Reaction Steps
Compound 5 (54.8 mg, 0.12 mmol) in CH2Cl2 (2 mL) at 0° C. was added dropwise to a stirred solution of 3-benzyloxy-1-propanol (16.6 mg, 0.1 mmol), 1,3-dicyclohexylcarbodiimide (31 mg, 0.15 mmol) and 4-dimethylaminopyridine (14.6 mg, 0.12 mmol) in dry CH2Cl2 (1 mL). The mixture was stirred for 4 h at room temperature and concentrated in vacuo. The residue was chromatographed over silica gel using CH2Cl2/MeOH (50:1, v/v) to give 6 (61.2 mg, 84%) as a yellow liquid. 1H NMR (CDCl3) δ 8.16 (s, 1H, H4), 7.47 (d, 1H, H5, J=8.7 Hz), 7.20-7.45 (m, 11H, H6+2×OCH2Ph), 6.82 (d, 1H, H5′, J=7.8 Hz), 6.76 (d, 1H, H2′, J=1.5 Hz), 6.70 (dd, 1H, H6′, J=1.5, 7.8 Hz), 6.06 (AB, 2H, 3′,4′-OCH2O—, Δδ=9.9 Hz, J=1.5 Hz), 5.84 (AB, 2H, 7,8-OCH2O—, Δδ=4.5 Hz, J=1.5 Hz), 4.65 (s, 2H, OCH2Ph), 4.53 (s, 2H, OCH2Ph), 4.42 (t, 2H, 3-COOCH2(CH2)2OBn, J=6.3 Hz), 4.35 (s, 2H, 2-CH2OBn), 3.62 (t, 2H, 3-COO(CH2)2CH2OBn, J=6.3 Hz), 2.06 (quintet, 2H, 3-COOCH2CH2CH2OBn, J=6.3 Hz); MS (EI) m/z 604 [M]+.
