反应详情

To tetrahydro-4H-pyran-4,4-dicarboxylic acid dimethyl ester (4.04 g) was added 20% HCl (20 mL), and the mixture was heated under reflux for 19 hours. Water was added to the reaction mixture, and the thus-obtained mixture was extracted with diethyl ether. The organic layer was washed with saturated brine, and was dried over sodium sulfate anhydrate. The solvent was distilled away under reduced pressure, and hexane was added to the residue. The resultant solid was collected by filtration, and was washed, to thereby give the title compound (2.63 g).

1. temperaturethe mixture was heated
2. temperatureunder reflux for 19 hours
3. extractionthe thus-obtained mixture was extracted with diethyl ether
4. washThe organic layer was washed with saturated brine
5. dry with materialwas dried over sodium sulfate anhydrate
6. distillationThe solvent was distilled away under reduced pressure, and hexane
7. additionwas added to the residue
8. filtrationThe resultant solid was collected by filtration
9. washwas washed