Reaction Steps
Methyl 3,4-di-O-benzyl-6-O-(4-chlorobenzyl)-β-D-glucopyranoside (0.258 g, 0.517 mmol) was dissolved in 3 mL CH2Cl2. 2,6-lutidine (240 μL, 2.06 mmol) and tert-butyldimethylsilyltrifluoromethane sulfonate (0.284 mL, 1.24 mmol) were added and the reaction mixture was stirred at room temperature for 30 min. The solution was filtered through silica, eluted with EtOAc and concentrated. Purification by flash column chromatography on silica gel (10% EtOAc/Hexanes) gave 283 mg (89%) of 22 as a colorless oil. [α]24D: −9.2° (c 2.01, CH2Cl2); IR (thin film) 2928, 2855, 1492, 1069 cm−1; 1H-NMR (CDCl3) δ 7.41-7.29 (m, 12H), 7.16-7.13 (m, 2H), 4.97 (d, J=11.3 Hz, 1H), 4.90 (d, J=11.3 Hz, 1H), 4.82 (d, J=11.0 Hz, 1H), 4.61 (d, J=12.5 Hz, 1H), 4.56-4.53 (m, 2H), 4.17 (d, J=7.3 Hz, 1H), 3.78-3.76 (m, 1H), 3.71 (dd, J=4.6, 10.7 Hz, 1H), 3.63-3.53 (m, 6H), 0.95 (s, 9H), 0.17 (s, 3H), 0.13 (s, 3H), 13C-NMR (CDCl3) δ 138.8, 138.1, 136.8, 133.5, 129.2, 128.6, 128.5, 128.4, 128.3, 128.0, 127.9, 127.5, 104.9, 86.0, 78.3, 75.8, 75.4, 75.1, 74.9, 72.8, 69.1, 57.9, 26.1, 18.4, −4.1, −4.2; FAB MS m/z (M+Na)+: calcd 635.2572, obsd 635.2574.
