反応 #46986

反応方程式

hydrochloric acid

4-propionyltetrahydropyran

dimethyl carbonate

sodium methoxide

→

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

収率 33.3%

溶媒

water

ethyl acetate

反応条件

後処理

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

実験手順

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.

出典