Acetic Acid → 2-Ethyl-4-hydroxy-3-methylcyclopent-2-en-1-one

Beteiligte Stoffe

Reaktionsschritte

A mixed solution of 28.97 g of the 1-(5-methyl-2-furyl)propanol thus obtained, 0.394 g of 50% aqueous acetic acid, 0.394 g of a 23% (w/v) sodium hydroxide solution in 579.4 g of water was heated and refluxed at the constant pH of 5.70 to 5.85 for 38 hours. After the mixed solution was cooled to the room temperature, a 23% (w/v) sodium hydroxide solution was added to the mixed solution to adjust the pH of the solution to 8.0 to 8.2, and then refluxed for three hours. A 50% acetic acid solution was added to the refluxing solution to adjust the pH to 6.0 to 6.5. The reaction solution was then cooled to the room temperature, mixed with 300 g of sodium chloride, and extracted three times with 500 ml of diethyl ether. The combined ether layer was washed twice with a saturated sodium chloride solution and dried over anhydrous magnesium sulfate. After removal of the solvent under reduced pressure, the residue was distilled, and a distillate fraction of 157° to 162° C. at 19 mmHg was collected to yield 15 g of (RS)-4-hydroxy-3-methyl-2-ethylcyclopent-2-en-1-one. Yield 52%

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