反应详情

To prepare 8, a solution of 38 (22.6 mg, 66.8 μmol) and 3-azido-(2R)-methylpropanoic acid (Rej et al., J. Org. Chem. 61:6289-95 (1996), which is hereby incorporated by reference in its entirety) (37, 8.6 mg, 66.8 μmol) in 2 mL dichloromethane was treated with 4-dimethylaminopyridine (16.3 mg, 133.6 μmol) and EDC hydrochloride (25.7 mg, 133.6 μmol). After stirring at room temperature for 12 hours the reaction was quenched by addition of 5% aqueous acetic acid (100 μl), dried over Na2SO4, and concentrated in vacuo. Flash column chromatography on silica using a gradient of 0-10% isopropanol in dichloromethane afforded (R)-benzyl 4-(((2R,3R,5R,6S)-5-(((R)-3-azido-2-methylpropanoyl)oxy)-3-hydroxy-6-methyltetrahydro-2H-pyran-2-yl)oxy)pentanoate (8) (5.2 mg, 11.6 μmol, 17%) as a colorless oil. 1H NMR (400 MHz, chloroform-d): δ (ppm) 7.40-7.31 (m, 5H), 5.15 (d, J=13.6 Hz, 1H), 5.11 (d, J=13.6 Hz, 1H), 4.86 (ddd, J=10.9 Hz, 9.4 Hz, 4.6 Hz, 1H), 4.73-4.70 (m, 1H), 3.90-3.76 (m, 3H), 3.52 (dd, J=12.2 Hz, 7.5 Hz, 1H), 3.38 (dd, J=12.2 Hz, 5.6 Hz, 1H), 2.71-2.60 (m, 1H), 2.57-2.42 (m, 2H), 2.13-2.05 (m, 2H), 1.93-1.83 (m, 3H), 1.20 (d, J=7.0 Hz, 3H), 1.17 (d, J=6.3 Hz, 3H), 1.16 (d, J=6.2 Hz, 3H). See FIG. 105.

1. customTo prepare 8
2. customwas quenched by addition of 5% aqueous acetic acid (100 μl)
3. dry with materialdried over Na2SO4
4. concentrationconcentrated in vacuo