Reaction Steps
To a stirred solution of methyl 4-O-benzyl-2,3-di-O-methoxymethyl-α-D-glucopyranoside (D. B. Berkowitz et al., J. Org. Chem. 1993, vol. 58, page 6174) (1.1 g, 2.96 mmol) in methylene chloride (10 mL) was added triethyl-amine (3.4 mL, 24.5 mmol), and benzoyl chloride (1.4 mL, 12.0 mmol). The reaction was stirred at room temperature for approximately 30 min and then diluted with EtOAc (100 mL) and washed with 0.5 N aqueous HCl (100 mL), saturated aqueous NaHCO3 (100 mL), and brine (100 mL). The aqueous layers were reextracted with EtOAc (100 mL) and the organics were combined, dried over Na2SO4, and then concentrated in vacuo. The crude product was taken up in ethanol (7 mL) and Pd/C-Degussa type (100 mg) was added. The reaction was stirred under an atmosphere of hydrogen for 12 h and then filtered through celite and concentrated in vacuo. The product was purified by flash chromatography (gradient 33% to 50% EtOAc/petroleum ether) to afford 2 (0.70 g, 61%) as a colorless oil: Rf=0.25 (40% EtOAc/petroleum ether); 1H NMR (CDCl3, 270 MHz) δ 8.06 (d, J=7.2 Hz, 2H), 7.56 (t, J=7.2 Hz, 1H), 7.44 (t, J=7.2 Hz, 2H), 4.84 (d, J=3.6 Hz, 1H), 4.7-4.8 (m, 4H), 4.65 (dd, J=2.3, 11.9 Hz, 1H), 4.57 (dd, J=5.3, 11.9 Hz, 1H), 4.23 (br s, 1H), 3.91 (ddd, J=2.3, 5.3, 9.5 Hz, 1H), 3.71 (dd, J=9.5, 9.5 Hz, 1H), 3.61 (dd, J=3.6, 9.5 Hz, 1H), 3.50 (dd, J=9.5, 9.5 Hz, 1H), 3.46 (s, 3H), 3.45 (s, 3H), 3.39 (s, 3H); 13C NMR (CD3COCD3, 67.5 MHz) δ 167.0, 134.2, 131.5, 130.5, 129.7, 100.1, 98.8, 98.1, 81.0, 79.2, 71.4, 70.7, 65.2, 56.1, 55.7, 55.5; HRFABMS calcd for C18H27O9 (M+H+) 387.1655, found 387.1656.
