反应详情

Sodium hydroxide (24.0 g) and water (450 ml) were added to 5-(4-methoxyphenyl)-2-oxopentanoic acid (66.6 g) (the compound of Reference Example 2), and the resulting mixture was ice-cooled. When to this slurry was added sodium tetrahydroborate (3.99 g) in portions, the reaction mixture once became clear. After the reaction mixture was stirred for 2 hours, a 3N aqueous hydrochloric acid solution (300 ml) was added thereto, followed by extraction with ethyl acetate (300 ml×twice). The organic layer was washed with water (100 ml×three times) and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure to obtain 2-hydroxy-5-(4-methoxyphenyl)pentanoic acid (63.4 g) as a crude product.

1. temperaturecooled
2. extractionfollowed by extraction with ethyl acetate (300 ml×twice)
3. washThe organic layer was washed with water (100 ml×three times)
4. dry with materialdried over anhydrous sodium sulfate
5. distillationThe solvent was distilled off under reduced pressure