Reaktion #95306

Reaktionsgleichung

4-bromo-2-(6-carbethoxyhexyl)cyclopent-2-en-1-one

acetic acid

→

4-acetoxy-2-(6-carbethoxyhexyl)cyclopent-2-en-1-one

Lösungsmittel

MeOH

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONA mixture of 51.6 g
2. 2
   Temperaturat reflux for 4.5 hours
3. 3
   TemperaturThe mixture is cooled
4. 4
   Sonstigesolids are removed by filtration
5. 5
   EinengenThe filtrate is concentrated
6. 6
   Extraktionextracted with hot hexane
7. 7
   WaschenThe extract is washed with saturated sodium bicarbonate solution and saturated sodium chloride solution
8. 8
   Trocknendried over mangesium sulfate
9. 9
   Einengenconcentrated
10. 10
    Sonstigeto give an oil
11. 11
    workup.DISTILLATIONThe crude product is distilled at reduced pressure
12. 12
    Sonstigeto give a liquid, b.p. 152°-163° C. (0.01 mm)

Vorschrift

A mixture of 51.6 g. (0.137 moles) of crude 4-bromo-2-(6-carbethoxyhexyl)cyclopent-2-en-1-one (Example 1274), 27 g. (0.162 moles) of silver acetate, and 200 ml. of glacial acetic acid is stirred at reflux for 4.5 hours. The mixture is cooled, and solids are removed by filtration. The filtrate is concentrated and extracted with hot hexane. The extract is washed with saturated sodium bicarbonate solution and saturated sodium chloride solution, dried over mangesium sulfate, and concentrated to give an oil. The crude product is distilled at reduced pressure to give a liquid, b.p. 152°-163° C. (0.01 mm); λmax.MeOH =223 mμ (10700); νmax.=1745 (ester carbonyl groups), 1725 (ketone carbonyl groups), and 1235 cm-1 (acetoxy group).

Quelle