反应详情

In methanol was dissolved 18.1 g (59.5 mmol) of methyl 4-{(2E)-3,7-dimethylocta-2,6-dienyloxy}-2-hydroxybenzoate, and 30 ml of an aqueous solution of 8.35 g (148 mmol) of potassium hydroxide was added thereto, followed by heating under reflux for 5 hours. Methanol was evaporated, and a 12% hydrochloric acid aqueous solution added to the residue, followed by extraction with ethyl acetate. The organic layer was washed successively with water and a saturated aqueous solution of sodium chloride and dried over sodium sulfate, followed by concentration. The resulting crude product was recrystallized from an ethyl acetate/hexane mixed solvent to obtain 13.06 g (yield: 75%) of 4-{(2E)-3,7-dimethylocta-2,6-dienyloxy}-2-hydroxybenzoic acid represented by the following structural formula (hereinafter referred to as compound 39) as white crystals. The analytical results are shown below. ##STR60##

1. additionwas added
2. temperatureby heating
3. temperatureunder reflux for 5 hours
4. customMethanol was evaporated
5. additiona 12% hydrochloric acid aqueous solution added to the residue
6. extractionfollowed by extraction with ethyl acetate
7. washThe organic layer was washed successively with water
8. dry with materiala saturated aqueous solution of sodium chloride and dried over sodium sulfate
9. concentrationfollowed by concentration
10. customThe resulting crude product was recrystallized from an ethyl acetate/hexane mixed solvent