Reaction Steps
1,3,4,6-Tetra-O-acetyl-2-deoxy-2-phthalimido-β-D-galactopyranose (Nilsson, U. et al. Carbohydr. Res. 1990, 208, 260) (1.7 g, 3.56 mmol) in CH2Cl2 (20 mL) was treated with thiocresol (663 mg, 5.34 mmol) and BF3.Et2O (1.5 mL) by the procedure described in the preparation of 1. After workup, the crude product was crystallized from Et2O. to gave the title compound 11 (1.62 g, 83%): m.p. 141-142° C.; [α]D22 +45.4° (c, 0.5, CHCl3); 1H-NMR (400 MHz, CDCl3), δ 1.97 (s, 3H), 2.05 (s, 3H), 2.08 (s, 3H), 2.31 (s, 3H), 4.09-4.24 (m, 3H), 4.62 (t, 1H, J=10.8 Hz), 5.49 (d, 1H, J=3.2 Hz), 5.64 (d, 1H, J=10.8 Hz), 5.80 (dd, 1H, J=10.8, 3.2 Hz), 7.07 (d, 2H, J=8.1 Hz), 7.32 (d, 2H, J=8.1 Hz), 7.76-7.80 (m, 4H); 13C-NMR (400 MHz, CDCl3) δ 20.52, 20.69, 21.14, 50.11, 61.63, 66.85, 68.81, 74.48, 84.35, 123.65, 129.62, 133.21, 134.40, 162.01, 163.10, 167.16, 167.90, 171.22; HRMS for C27H27NO9SCs (M+Cs) calcd 674.0461, found 674.0435.
