反应详情

A solution of 13 mg (0.045 millimole) of (E)-3-cyclohexyl-2-(hydroxyisobutylphosphinoyl)methylpropenoic acid in 0.13 ml of 4.3 N hydrogen chloride-butyl acetate was heated at 100° C. in a sealed tube for 24 hours. After cooling, the solvent was evaporated under reduced pressure. The residue was dissolved in 0.2 ml of ethanol, and 0.1 ml of 6 N sodium hydroxide was added. The mixture was heated under reflux for 1.5 hours. After cooling, 5 ml of water was added and hydrochloric acid was also added to acidify the mixture. The mixture was then extracted three times with 5 ml of ethyl acetate each time. The combined ethyl acetate layers were washed with 5 ml of a saturated aqueous solution of sodium chloride, and dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure. The residue was recrystallized from ethyl acetate/hexane to give 7 mg (yield 54%) of (Z)-3-cyclohexyl-2-(hydroxyisobutylphosphinoyl)methylpropenoic acid as colorless crystals. Its melting point and IR and 1H-NMR data were identical with those of the product obtained in Example 5 (b).

1. temperatureAfter cooling
2. customthe solvent was evaporated under reduced pressure
3. dissolutionThe residue was dissolved in 0.2 ml of ethanol
4. addition0.1 ml of 6 N sodium hydroxide was added
5. temperatureThe mixture was heated
6. temperatureunder reflux for 1.5 hours
7. temperatureAfter cooling
8. addition5 ml of water was added
9. additionhydrochloric acid was also added
10. extractionThe mixture was then extracted three times with 5 ml of ethyl acetate each time
11. washThe combined ethyl acetate layers were washed with 5 ml of a saturated aqueous solution of sodium chloride
12. dry with materialdried over anhydrous magnesium sulfate
13. customThe solvent was evaporated under reduced pressure
14. customThe residue was recrystallized from ethyl acetate/hexane