Thiophenol → Phenyl 2,3,4,6-tetra-O-acetyl-1-thio-beta-D-galactopyranoside

Participants

Reaction Steps

To a solution of galactose pentaacetate (5.00 g, 12.8 mmol) in 125 mL of CH2Cl2 is added thiophenol (1.49 mL, 14.1 mmol) and boron trifluoride diethyl ether complex (4.73 mL, 38.4 mmol). The reaction mixture is stirred at room temperature for 5 h and then poured into 200 mL of ice water. The organic layer is washed with saturated NaHCO3 (200 ml), dried over Na2SO4, filtered, concentrated and purified by flash chromatography (35% EtOAc/hexane) to give 5.4 g (96%) of 1-deoxy-1-(phenylthio)-2,3,4,6-tetra-O-acetyl-β-D-galactopyranose 39: Rf 0.22 (35% EtOAc/hexane); 1H NMR (CDCl3, 270 MHz) δ 7.35-7.65 (m, 5 H, ArH), 5.50 (br d, J=3.3 Hz, 1 H, H-4), 5.32 (t, J=9.8 Hz, 1 H, H-2), 5.13 (dd, J=9.8, 3.3 Hz, 1 H, H-3), 4.80 (d, J=9.8 Hz, 1 H, H-1), 4.13-4.32 (m, 2 H, H-6, H-6'), 4.02 (br t, J=6.5 Hz, 1 H, H-5), 2.02-2.23 (4s, 12 H, OAc).

Provenance & Evidence