反应详情

A suspended mixture of p-Methylphenyl 1-thio-β-D-galactopyranoside (Vargas-Berenguel, A. et al. J. Chem. Soc. Perkin Trans 1 1994, 3287) (100 mg, 0.350 mmol) and Bu2SnO (266 mg, 1.04 mmol) in toluene-benzene (1:1, 10 mL) was refluxed for 10 min. The mixture was concentrated to a volume of 2 mL by distillation under Ar, then the hot solution (about 100° C.) was treated with benzoyl chloride (130 μL, 1.12 mmol). After being stirred for 1 h at this temperature, the reaction mixture was diluted with EtOAc (20 mL), cooled to room temperature, filtered through Celite and concentrated. Chromatography of the residue (hexane/EtOAc, 4:1 to 2:1 to 1:1) furnished 15 (192 mg, 91.7%) as white white solid: [α]D22 +15° (c, 0.5, CHCl3); 1H-NMR (250 MHz, CDCl3), δ 5.91 (d, 1H, J=3.1 Hz, H-4), 5.43 (dd, 1H, J=3.3, 9.7 Hz, H-3), 4.720 (d, 1H, J=9.6 Hz, H-1), 4.29 (bt, 1H, J=6.5 Hz, H-5), 4.62 (dd, 1H, J=6.6 Hz, H-6) 4.37 (dd, 1H each, J=11.5 Hz, H-6′), 4.03 (t, 1H, J=9.6 Hz, H-2), 2.38 (s, 3H, Me); 13C-NMR (270 MHz, CDCl3) δ 165.98, 165.90, 165.29, 88.26, 74.97, 74.47, 68.59, 67.34, 62.45, 21.28; HRMS for C40H44O8SiCs (M+Cs) calcd 845.1581. found 845.1609.

1. concentrationThe mixture was concentrated to a volume of 2 mL by distillation under Ar
2. filtrationfiltered through Celite
3. concentrationconcentrated