Reaktion #46983

Reaktionsgleichung

hydrochloric acid

4-acetyltetrahydropyran

dimethyl carbonate

sodium methoxide

→

methyl 3-(4-tetrahydropyranyl)-3-oxopropanoate

Ausbeute 80.5%

Lösungsmittel

water

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeIn a flask made of glass
2. 2
   Sonstigeequipped with a stirring device
3. 3
   Sonstigethe mixture was reacted at 80 to 85° C. for 2 hours
4. 4
   workup.DISTILLATIONwith distilling
5. 5
   Sonstigeby-producing methanol off
6. 6
   SonstigeAfter completion of the reaction
7. 7
   SonstigeAfter the organic layer was separated
8. 8
   Extraktionthe aqueous layer was extracted twice with 70 ml of toluene
9. 9
   EinengenThe organic layer was concentrated under reduced pressure
10. 10
    Sonstigethe concentrate was purified by silica gel column chromatography (Fluent; hexane/ethyl acetate=1/1 (volume ratio))

Vorschrift

In a flask made of glass having an inner volume of 500 ml and equipped with a stirring device, a thermometer, a dropping funnel and a distillation device were charged 35.0 g (273 mmol) of 4-acetyltetrahydropyran synthesized in the same manner as in Reference example 2, 280.0 g (3.1 mol) of dimethyl carbonate and 16.3 g (302 mmol) of sodium methoxide, and the mixture was reacted at 80 to 85° C. for 2 hours with distilling by-producing methanol off. After completion of the reaction, the reaction mixture was cooled to 5 to 10° C., and to the reaction mixture were added 175 ml of toluene, 55 ml (330 mmol) of 6 mol/l hydrochloric acid and 35 ml of water in this order. After the organic layer was separated, the aqueous layer was extracted twice with 70 ml of toluene. The organic layer was concentrated under reduced pressure, and the concentrate was purified by silica gel column chromatography (Fluent; hexane/ethyl acetate=1/1 (volume ratio)) to give 40.9 g (Isolation yield: 76%) of methyl 3-(4-tetrahydropyranyl)-3-oxopropanoate with a purity of 93.9% (analytical value by differential diffractometry) as a colorless liquid.

Quelle