Ethanethiol → Ethyl 2,4,6-Tri-O-acetyl-3-O-methyl-1-thio-beta-D-glucopyranoside

Participants

Reaction Steps

1,2,4,6-Tetra-O-acetyl-3-O-methyl-β-D-glucopyranose 1 (69 g, 0.19 mmol), (B. Helferich et al., J. prakt. Chem., 132, 321 (1932)) is dissolved in toluene (580 ml). Ethanethiol (28 ml, 0.38 mmol) is added, followed by dropwise addition of a solution of trifluoroborane diethyl etherate (1 M in toluene, 190 ml). The mixture is left stirring for 1.5 hours (TLC), solid sodium hydrogen carbonate is introduced and the mixture is filtered, washed with water, dried and concentrated. Chromatography on a column of silica (3/1 cyclohexane/ethyl acetate) gives 2 (37 g, 54%) [α]D−26 (c=1. dichloromethane). 1H NMR (CDCl3). δ 5.05-4.96 (m, 2H, H-2, H-4), 4.39, (d, 1H, J=9.5 Hz, H-1), 4.18-4.12 (m, 2H, H-6, H-6′), 3.60 (m, 1H, H-5), 3.50 (dd, 1H, J=9.3 Hz, H-3), 3.41 (s, 3H, OCH3), 2.65-2.53 (m, 2H, SCH2CH3), 2.12, 2.11, 2.09 (3s, 9H, 3 Ac), 1.25 (t, 1H, SCH2CH3)

Provenance & Evidence