Reaction Steps
To a solution of 43 (1.49 g, 2.49 mmol) in 50 mL CH2Cl2 is added thiophenol (0.64 mL, 686 mg, 6.22 mmol) followed by boron trifluoride diethyl ether complex (1.53 mL, 1.76 g, 12.45 mmol). The reaction mixture is stirred at room temperature for 4 h and quenched by the slow addition of 10 mL saturated NaHCO3 solution. The reaction mixture is diluted with 100 mL of CH2Cl2, washed with H2O (100 mL), saturated NaCl (100 mL), dried over Na2SO4, filtered, concentrated and purified by flash chromatography (5% EtOAc/hexane) to afford 1.24 g (82%) of 1-deoxy-1-(phenylthio)-2,3,4,6-tetra-O-pivaloyl-β-D-glucopyranose 44: Rf 0.25 (5% EtOAc/hexane); 1H NMR (CDCl3, 270 MHz) δ 7.47-7.50 (m, 2H), 7.22-7.30 (m, 3H), 5.34 (app t, J=9.4 Hz, 1H, H-3), 5.08 (app t, J=9.7 Hz, 1H, H-4), 5.03 (app t, J=9.7 Hz, 1H, H-2), 4.73 (d, J=9.8 Hz, 1H, H-1), 4.25 (dd, J=12.2, 1.6 Hz, 1H, H-6), 4.04 (dd, J=12.2, 5.9 Hz, 1H, H-6), 3.76 (ddd, J=10.2, 5.9, 1.6 Hz, 1H, H-5), 1.21 (s, 9H), 1.20 (s, 9H), 1.14 (s, 9H), 1.10 (s, 9H); 13C NMR (CDCl3, 68 MHz) δ 177.8, 176.9, 176.2, 176.1, 132.5, 132.2, 129.2, 129.1, 128.1. 128.8, 86.4, 76.3, 73.1, 69.3, 67.5, 62.1, 38.7, 38.6, 27.4, 27.0, 29.9; FABMS C32H48O9S (MNa+) calcd 631.2917, found 631.2943.
