反应详情

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 4.8 g (24 mmol) of 4-propionyl-4-methoxycarbonyltetrahydropyran synthesized in Example 2, 30 ml of water and 9.0 g of conc. sulfuric acid, and the mixture was reacted at 100° C. for 10 hours with stirring. After completion of the reaction, to the resulting reaction mixture was added 16.5 g of 50% by weight aqueous sodium hydroxide solution to adjust a pH of the mixture to 4.0. Said reaction mixture was extracted three times with 50 ml of ethyl acetate, and the organic layer was separated and concentrated under reduced pressure. The obtained concentrate was purified by silica gel column chromatography (Eluent; hexane/ethyl acetate=3/1 (volume ratio)) to give 2.58 g (Isolation yield: 76%) of 4-propionyltetrahydropyran as a pale yellow liquid.

1. customIn a flask made of glass
2. customequipped with a stirring device
3. customthe mixture was reacted at 100° C. for 10 hours
4. customAfter completion of the reaction
5. customto the resulting reaction mixture
6. customreaction mixture
7. extractionwas extracted three times with 50 ml of ethyl acetate
8. customthe organic layer was separated
9. concentrationconcentrated under reduced pressure
10. concentrationThe obtained concentrate
11. customwas purified by silica gel column chromatography (Eluent; hexane/ethyl acetate=3/1 (volume ratio))