Reaktion #46986

Reaktionsgleichung

hydrochloric acid

4-propionyltetrahydropyran

dimethyl carbonate

sodium methoxide

→

methyl 3-(4-tetrahydropyranyl)-2-methyl-3-oxopropanoate

Ausbeute 33.3%

Lösungsmittel

water

ethyl acetate

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 50 ml of ethyl acetate
9. 9
   EinengenThe organic layer was concentrated under reduced pressure
10. 10
    Sonstigethe concentrate was purified by silica gel column chromatography (Eluent; hexane/ethyl acetate=3/1 (volume ratio))

Vorschrift

In a flask made of glass having an inner volume of 100 ml and equipped with a stirring device, a thermometer, a dropping funnel and a distillation device were charged 1.28 g (9 mmol) of 4-propionyltetrahydropyran synthesized in the same manner as in Example 5, 16.0 g (180 mmol) of dimethyl carbonate and 1.2 g (22 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., to the reaction mixture were added 50 ml of ethyl acetate, 3.4 g (24 mmol) of 6 mol/l hydrochloric acid and 15 ml of water in this order. After the organic layer was separated, the aqueous layer was extracted twice with 50 ml of ethyl acetate. The organic layer was concentrated under reduced pressure, and the concentrate was purified by silica gel column chromatography (Eluent; hexane/ethyl acetate=3/1 (volume ratio)) to give 0.60 g (Isolation yield: 33%) of methyl 3-(4-tetrahydropyranyl)-2-methyl-3-oxopropanoate as a colorless liquid.

Quelle