Reaction Steps
To a solution of allyl α-D-glactonpyranoside (1, 5.0 g, 22.7 mmol) in 100 mL of dry pyridine at −35˜−30° C. was added benzoyl chloride dropwise with stirring. The reaction mixture was stirred at that temperature for 20 mins, then warmed to room temperature and stirred at room temperature for 48 h. The reaction was quenched by the dropwise addition of the reaction mixture to 200 ml of ice-cold saturated aqueous sodium bicarbonate with stirring. The aqueous mixture was extracted with EtOAc three times (150 ml each time). The combined extracts were washed with 1N HCl six times, brine, dried over Na2SO4, then evaporated to dryness in vacuo to give the crude product as light orange oil, which was purified by flash column chromatography on silica gel (150 g AnaLogix column, EtOAc/heptane: 0>>>5%>>>15%>>>35%) to yield compound 2 (8.55 g, 70.7%) as a white solid. 1H NMR (CDCl3) δ 8.07 (s, 1H), 8.05 (d, J=1.01 Hz, 1H), 8.01 (dd, J=3.03, 1.52 Hz, 2H), 7.99 (dd, J=3.03, 1.52 Hz, 2H), 7.59 (m, 1H), 7.52 (m, 2H), 7.46 (t, J=7.58 Hz, 2H), 7.35-7.42 (4H), 5.86 (ddd, J=16.67, 11.12, 5.56 Hz, 1H), 5.79 (dd, J=11.12, 0.03 Hz, 1H), 5.70 (dd, J=10.61, 3.54 Hz, 1H), 5.35 (d, J=3.54 Hz, 1H), 5.27 (dq, J=17.18, 1.52 Hz, 1H), 5.12 (dq, J=10.61, 1.52 Hz, 1H), 4.68 (dd, J=11.62, 6.57 Hz, 1H), 4.55 (dd, J=11.12, 6.57 Hz, 1H), 4.42 (m, 2H), 4.25 (m, 1H), 4.10 (m, 1H), 2.47 (d, J=4.04 Hz, 1H). MS (ES) 554.8 (M+Na+).
