反应详情

温度

30 °C

A solution of 9 g of 2-carbethoxy-2,5-dimethyl-3-oxo-4-hydroxy-2H-furan and 5.4 g of sodium hydroxide in 50 ml of water is kept at room temperature under nitrogen for 20 hours. The reaction mixture is acidified with hydrochloric acid, then stirred at 30° C. for an hour and continuously extracted for 6 hours with ether. The ether extract is dried and the solvent is removed under vacuum, the residue is dissolved in a mixture of 5 ml of dry ether and 5 ml of dry pentane. The solution is cooled to -10° C. and filtered. The solid product is dried, yielding 4.1 g (70%) of 4-hydroxy-2,5-dimethyl-3-oxo-2H-furan. The isolated product is identical (NMR and IR) with a sample of 4-hydroxy-2,5-dimethyl-3-oxo-2H-furan prepared from rhamnose (loc cit). M.p. 82°-84° C.

1. extractioncontinuously extracted for 6 hours with ether
2. extractionThe ether extract
3. customis dried
4. customthe solvent is removed under vacuum
5. dissolutionthe residue is dissolved in a mixture of 5 ml of dry ether and 5 ml of dry pentane
6. temperatureThe solution is cooled to -10° C.
7. filtrationfiltered
8. customThe solid product is dried