Reaktion #46982

Reaktionsgleichung

sodium sulfate

4-acetyl-4-methoxycarbonyltetrahydropyran

hydrogen peroxide

sodium hydroxide

hydrogen peroxide

→

4-acetyltetrahydropyran

Ausbeute 88.2%

Lösungsmittel

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeIn a flask made of glass
2. 2
   Sonstigeequipped with a stirring device
3. 3
   Sonstigethe mixture was reacted at 40° C. for 5 hours
4. 4
   workup.STIRRINGwith stirring
5. 5
   SonstigeAfter completion of the reaction
6. 6
   Sonstigeto the resulting reaction mixture
7. 7
   Einengenthe mixture was concentrated under reduced pressure
8. 8
   Extraktionthe concentrate was extracted three times with 500 ml of ethyl acetate
9. 9
   workup.DISTILLATIONThe organic layer was distilled under reduced pressure (90 to 92° C., 2.0 kPa)

Vorschrift

In a flask made of glass having an inner volume of 10 ml and equipped with a stirring device, a thermometer, a dropping funnel and a reflux condenser were charged 202 g (1.0 mol) of 4-acetyl-4-methoxycarbonyltetrahydropyran with a purity of 95% and synthesized in the same manner as in Reference example 1 and 720 ml of methanol, and the temperature of the mixture was raised to 35° C. with stirring. Then, to the mixture was gently added dropwise a mixed solution comprising 201 g (2.0 mol) of 35% by weight aqueous hydrogen peroxide solution and 91 ml (0.73 mol) of 8 mol/l aqueous sodium hydroxide solution, and the mixture was reacted at 40° C. for 5 hours with stirring. After completion of the reaction, to the resulting reaction mixture was added a saturated aqueous sodium sulfate solution to decompose the remaining hydrogen peroxide, then, the mixture was concentrated under reduced pressure, and the concentrate was extracted three times with 500 ml of ethyl acetate. The organic layer was distilled under reduced pressure (90 to 92° C., 2.0 kPa) to give 113 g (Isolation yield: 85%) of 4-acetyltetrahydropyran with a purity of 99% (areal percentage by gas chromatography) as a colorless liquid.

Quelle