Methanol → Methyl D-glucoside
Reaktionsgleichung
[OH:1][C@H:2]1[O:10][C@H:9]([CH2:11][OH:12])[C@@H:7]([OH:8])[C@H:5]([OH:6])[C@H:3]1[OH:4].[CH3:13]O>>[O:1]([CH3:13])[CH:2]1[O:10][C@H:9]([CH2:11][OH:12])[C@@H:7]([OH:8])[C@H:5]([OH:6])[C@H:3]1[OH:4]Komponenten
3
Reaktionsbedingungen
- Temperatur
- 65 °C
Versuchsvorschrift
α-D-glucose (500 g, 2.78 mol) and a strongly acidic cation exchange resin (100 g Amberlyst 15, BDH Chemicals) was suspended in methanol (1500 ml, 37.1 mol). The mixture was stirred at 65° C. for 68 hours. The progress of the reaction was followed by HPLC. 1H NMR analysis of the reaction mixture showed a 1:1 ratio of the α-and β-anomers. The ion exchange resin was removed by filtration and the solution was cooled to 4° C. The crystalline methyl α-D-glucopyranoside was removed by filtration (230 g, 43%) and the mother liquor was evaporated in vacuo to give a crude methyl D-glucopyranoside (304 g, 57%) as a thick syrup (1H NMR showed a ratio between α- and β-anomers of 2/3).