反应详情

A solution of ethyl 5-(4-methoxybenzoyl)pentanoate (50 g, 0.19 mole) in ethanol (500 ml) was cooled with ice, and sodium boron hydride (10 g) was added gradually to the solution. After the reaction was allowed to proceed for 1 hour, water (200 ml) and 2N hydrochloric acid (50 ml) were added to the reaction solution, followed by concentration under reduced pressure. The resulting residue was dissolved in ethyl acetate, and the organic layer was washed with water, dried and concentrated under reduced pressure. Methanol (300 ml), water (100 ml) and sodium hydroxide (40 g) were added to the resulting residue, followed by stirring for 2 hours, and the methanol was removed under reduced pressure. The water layer was washed with isopropyl ether and then adjusted to pH 4.0 with hydrochloric acid, followed by extraction with ethyl acetate. The organic layer was washed with water, dried and concentrated under reduced pressure, and the residue was chromatographed on a silica gel column, followed by elution with isopropyl ether-ethyl acetate (1:1) to give firstly 6-ethoxy-6-(4-methoxyphenyl)hexanoic acid (21 g) and then 6-hydroxy-6-(4-methoxyphenyl)hexanoic acid (20 g).

1. additionwas added gradually to the solution
2. concentrationfollowed by concentration under reduced pressure
3. dissolutionThe resulting residue was dissolved in ethyl acetate
4. washthe organic layer was washed with water
5. customdried
6. concentrationconcentrated under reduced pressure
7. additionMethanol (300 ml), water (100 ml) and sodium hydroxide (40 g) were added to the resulting residue
8. customthe methanol was removed under reduced pressure
9. washThe water layer was washed with isopropyl ether
10. extractionfollowed by extraction with ethyl acetate
11. washThe organic layer was washed with water
12. customdried
13. concentrationconcentrated under reduced pressure
14. customthe residue was chromatographed on a silica gel column
15. washfollowed by elution with isopropyl ether-ethyl acetate (1:1)