反应详情

(5R)-5-[(E)-2-(5-Bromo-6-methoxypyridin-2-yl)-2-(4-tert-butylphenyl)ethenyl]-1-(2,4-dimethoxybenzyl)pyrrolidin-2-one obtained in Reference Example 4-42(1) (100 mg) was dissolved in tetrahydrofuran (5 mL), and n-butyllithium was added at −78° C. After stirring for 30 minutes, cyclobutanone was added dropwise. The mixture was stirred for further 30 minutes and then an ammonium chloride solution was added to the reaction solution, followed by extraction with ethyl acetate. The organic layer was dried over sodium sulfate, and then the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (hexane:ethyl acetate=4:1→1:1) to give 5-{2-(4-tert-butylphenyl)-2-[5-(1-hydroxycyclobutyl)-6-methoxypyridin-2-yl]ethenyl}-1-(2,4-dimethoxybenzyl)pyrrolidin-2-one (EZ mixture) (35 mg).

1. stirringThe mixture was stirred for further 30 minutes
2. extractionfollowed by extraction with ethyl acetate
3. dry with materialThe organic layer was dried over sodium sulfate
4. customthe solvent was evaporated under reduced pressure
5. customThe residue was purified by silica gel column chromatography (hexane:ethyl acetate=4:1→1:1)