Benzyl Chloride → 3-Benzyloxy-2-ethyl-4-pyrone

Reaktionsgleichung

[CH2:1]([C:3]1[O:4][CH:5]=[CH:6][C:7](=[O:10])[C:8]=1[OH:9])[CH3:2].[OH-].[Na+].[CH2:13](Cl)[C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1>CO>[CH2:13]([O:9][C:8]1[C:7](=[O:10])[CH:6]=[CH:5][O:4][C:3]=1[CH2:1][CH3:2])[C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1

Komponenten

Versuchsvorschrift

To a suspension of 2-ethyl-3-hydroxy-4-pyrone (70 g, 0.5 mol) in methanol (650 ml) and sodium hydroxide solution (24 g, 0.6 mol of sodium hydroxide dissolved in 80 ml distilled water) was added benzyl chloride (90 ml, 0.75 mol) with stirring at room temperature. The reaction mixture was refluxed for 24 hours and then cooled. The solvent was removed by rotary evaporation and the residue was extracted into dichloromethane (500 ml). The organic layer was washed with 5% w/v sodium hydroxide solution (3×600 ml) and water (2×600 ml), dried over anhydrous sodium sulphate, filtered and rotary evaporated to give an oil. This oil was crystallized from diethylether in liquid nitrogen and the product recrystallized from diethylether to give the title compound (69 g, 65%) as colourless crystals, m.p. 33°-34° C.