反应详情

To a solution of 4-oxo-3-[4-(tetrahydropyran-2-yloxy)-phenyl]-butyric acid methyl ester (1.29 g) obtained in Step 3 in methanol (13 mL) was added camphorsulfonic acid (98 mg), followed by stirring the reaction mixture at room temperature for 6 hours. Then, after addition of 1N aqueous sodium hydroxide solution (0.42 mL), the reaction mixture was concentrated. To the residue was added water, followed by extraction with ethyl acetate. The organic layer was washed with saturated brine, dried and concentrated. The residue was purified by column chromatography on silica gel (ethyl acetate:hexane (volume ratio)=1:2 to 2:3) to give 3-(4-hydroxyphenyl)-4,4-dimethoxy butyric acid methyl ester (0.99 g).

1. concentrationthe reaction mixture was concentrated
2. additionTo the residue was added water
3. extractionfollowed by extraction with ethyl acetate
4. washThe organic layer was washed with saturated brine
5. customdried
6. concentrationconcentrated
7. customThe residue was purified by column chromatography on silica gel (ethyl acetate:hexane (volume ratio)=1:2 to 2:3)