反应详情

温度

115 °C

A mixture of propionic anhydride (4.0 ml) and propionic acid (4.0 ml) was added to 3-hydroxy-5-(3-methoxy-2,4,6-trimethylphenyl)cyclohex-2-en-1-one (2.0 g) and the mixture was heated at 115° C. with stirring until a clear solution was obtained. Trifluoromethanesulfonic acid (10 drops) was then added and the heating and stirring was continued for a further 2 hours. The mixture was cooled, poured into water, basified with sodium hydroxide and stirred at room temperature for 30 minutes. The aqueous mixture was then acidified to pH 6.0 with dilute hydrochloric acid and extracted with diethyl ether. The ether phase was washed successively with water, dilute aqueous sodium bicarbonate and water, then dried over anhydrous sodium sulfate and evaporated to give a crude red oil (2.3 g). Purification by column chromatography over silica gel (eluant dichloromethane) gave 3-hydroxy-5-(3-methoxy-2,4,6-trimethylphenyl)-2-propionylcyclohex-2-en-1-one (1.35 g; 55.0%) as a pale yellow oil. Proton magnetic resonance spectrum (CDCl3 ; δ in ppm): 1.15 (3H, t); 2.23 (3H, s); 2.33 (6H, s); 2.35-4.00 (7H, m); 3.66 (3H, s); 6.84 (1H, s); 18.24 (1H, s).

1. customwas obtained
2. stirringthe heating and stirring
3. temperatureThe mixture was cooled
4. stirringstirred at room temperature for 30 minutes
5. extractionextracted with diethyl ether
6. washThe ether phase was washed successively with water, dilute aqueous sodium bicarbonate and water
7. dry with materialdried over anhydrous sodium sulfate
8. customevaporated
9. customto give a crude red oil (2.3 g)
10. customPurification by column chromatography over silica gel (eluant dichloromethane)