反应详情

温度

-78 °C

In a 100 mL round bottom flask was added 2-azidoethyl 2,3,4-tri-O-benzoyl-α-D-mannopyranoside (720 mg, 1.282 mmol), 2,3,4,6-tetra-O-benzoyl-1-O-(2,2,2-trichloroethanimidoyl)-α-D-mannopyranose (1.14 g, 1.539 mmol) and 4 Å molecular sieves (300 mg). To the above mixture was added CH2Cl2 (10 mL). The reaction mixture was cooled to -78° C. To the above mixture was added TMSOTf (23.2 μL, 0.128 mmol). The mixture was allowed to gradually warm to 0° C. and stirred for 30 min. The reaction was then quenched with sat. NaHCO3, and the mixture was filtered through a pad of Celite. The filtrate was diluted with CH2Cl2 (20 mL), washed with brine and water. The organic phase was dried over MgSO4, filtered and concentrated. The residue was purified by flash chromatography on silica gel (80 g), eluting with 0-100% EtOAc in hexanes, to give the title product. LC-MS Method A: m/e=1157.64 [M+18] and 1163.52 [M+Na]; Rt=3.01 min. 1H NMR (CDCl3) δ 7.2-8.3 (m, 25H), 6.0 (t, 1H), 5.8 (t, 1H), 5.7 (m, 2H), 5.4 (s, 1H), 5.38 (m, 1H), 5.2 (s, 1H), 4.7 (dd, 1H), 4.6 (dd, 1H), 4.45 (m, 1H), 4.35 (dd, 1H), 3.9-4.0 (m, 2H), 3.8 (m, 2H), 3.7 (m, 1H), 3.4 (m, 2H).

1. temperatureto gradually warm to 0° C.
2. customThe reaction was then quenched with sat. NaHCO3
3. filtrationthe mixture was filtered through a pad of Celite
4. additionThe filtrate was diluted with CH2Cl2 (20 mL)
5. washwashed with brine and water
6. dry with materialThe organic phase was dried over MgSO4
7. filtrationfiltered
8. concentrationconcentrated
9. customThe residue was purified by flash chromatography on silica gel (80 g)
10. washeluting with 0-100% EtOAc in hexanes