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

関与物質

反応手順

To a stirred mixture of 2-ethyl-3-hydroxy-4-pyrone (49 g, 0.35 mol) in methanol (600 ml) and sodium hydroxide (16 g, 0.4 mol) dissolved in water (50 ml) was added benzyl chloride (47.2 ml, 0.41 mol) dropwise at room temperature. After heating under reflux for 48 hours the reaction mixture was cooled, filtered and the filtrate rotary evaporated to provide an oil. The oil was extracted with dichloromethane (300 ml), the solution washed with 5% w/v sodium hydroxide solution (3×250 ml) and water (3×250 ml), then dried over anhydrous sodium sulphate, filtered and rotary evaporated to provide an oil which was dissolved in diethyl ether and crystallized by coating with liquid nitrogen. Recrystallization from diethyl ether gave the title compound as colourless crystals (52.5 g, 65%), m.p. 33°-34° C.

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