반응 #46986

반응 방정식

hydrochloric acid

4-propionyltetrahydropyran

dimethyl carbonate

sodium methoxide

→

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

수율 33.3%

용매

water

ethyl acetate

반응 조건

후처리

1. 1
   기타In a flask made of glass
2. 2
   기타equipped with a stirring device
3. 3
   기타the mixture was reacted at 80 to 85° C. for 2 hours
4. 4
   workup.DISTILLATIONwith distilling
5. 5
   기타by-producing methanol off
6. 6
   기타After completion of the reaction
7. 7
   기타After the organic layer was separated
8. 8
   추출the aqueous layer was extracted twice with 50 ml of ethyl acetate
9. 9
   농축The organic layer was concentrated under reduced pressure
10. 10
    기타the concentrate was purified by silica gel column chromatography (Eluent; hexane/ethyl acetate=3/1 (volume ratio))

실험 절차

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.

출처