反应详情

To a solution of anhydrous zinc bromide (1.41 g, 6.3 mmol) in anhydrous tetrahydrofuran (8.0 ml) under nitrogen at 0°C., is added propynylmagnesium bromide (15.7 ml, 6.3 mmol, 0.4 M solution in tetrahydrofuran) dropwise. The reaction mixture is then allowed to warm to room temperature and stir for 10 minutes, then cooled again to 0°C. To this mixture is then added [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (0.102 g, 0.13 mmol), followed by a solution of 2-(4-bromo-2,6-dimethylphenyl)-3-methoxycyclopent-2-enone (0.370 g, 1.25 mmol) in anhydrous tetrahydrofuran (4.0 ml). The reaction mixture is heated at reflux for 4.5 hours, then allowed to cool to room temperature followed by quenching with saturated aqueous ammonium chloride (10 ml). Ethyl acetate is added, and the mixture is filtered through a bed of diatomaceous earth and the phases separated. The aqueous phase is extracted again with ethyl acetate (×3) and combined organics are washed with brine, dried over magnesium sulfate, filtered and the filtrate concentrated in vacuo. The residue is purified by flash column chromatography (ethyl acetate and isohexane as eluant) to afford 2-(2,6-dimethyl-4-prop-1-ynylphenyl)-3-methoxycyclopent-2-enone.

1. temperaturecooled again to 0°C
2. temperatureThe reaction mixture is heated
3. temperatureat reflux for 4.5 hours
4. temperatureto cool to room temperature
5. customby quenching with saturated aqueous ammonium chloride (10 ml)
6. additionEthyl acetate is added
7. filtrationthe mixture is filtered through a bed of diatomaceous earth
8. customthe phases separated
9. extractionThe aqueous phase is extracted again with ethyl acetate (×3)
10. washcombined organics are washed with brine
11. dry with materialdried over magnesium sulfate
12. filtrationfiltered
13. concentrationthe filtrate concentrated in vacuo
14. customThe residue is purified by flash column chromatography (ethyl acetate and isohexane as eluant)