反应详情

To the Grignard reagent prepared from 1.52 g (63 mg-atom) Mg turnings and 13.45 g (9 mL, 72 mmol) 4-bromoanisole (initiated with one I2 crystal and one drop EtBr2) in 25 mL THF was added 3 g (9.9 mmol) of Benzyl 4-benzyloxyphenyl ketone, prepared in Example 3. The reaction mixture was stirred at reflux for 48 h and then treated with 10 mL aqueous NH4Cl. After cooling to room temperature, the slurry was filtered, the filter cake washed with 50 mL THF, and the filtrates concentrated to give an orange oil. The oil was chromatographed over 60 g flash SiO2 (petroleum ether followed by Me2CO). The Me2CO fractions were combined, concentrated, dissolved in 100 mL 1:1 95% EtOH-2N H2SO4, and refluxed with stirring for 8 h. The solvents were removed to give a brown gum, which was dissolved in 100 mL Et2O, washed with saturated aqueous NaHCO3 (100 mL), brine (100 mL), and H2O (100 mL). The organic layer was dried (MgSO4), filtered, and concentrated to give a brown oil. The oil was purified on 60 g flash SiO2 (9:1 petroleum ether-CH2Cl2) to give 3.1 g of 1-(4-Benzyloxyphenyl)-1-(4-methoxyphenyl)-2-phenylethene (80%) as a clear oil. NMR δ7.41 (brs, 5H, O-benzyl C6H5), 7.3 to 6.75 (m, 9H, substituted rings' ArH and C=CH), 7.11 (s, 5H,=C--C6H5), 5.05 (s, 2H, OCH2Ph), 3.79 (s, 3H, OCH3).

1. customprepared in Example 3
2. temperatureat reflux for 48 h
3. filtrationthe slurry was filtered
4. washthe filter cake washed with 50 mL THF
5. concentrationthe filtrates concentrated
6. customto give an orange oil
7. customThe oil was chromatographed over 60 g flash SiO2 (petroleum ether followed by Me2CO)
8. concentrationconcentrated
9. dissolutiondissolved in 100 mL 1:1 95% EtOH-2N H2SO4
10. temperaturerefluxed
11. stirringwith stirring for 8 h
12. customThe solvents were removed
13. customto give a brown gum, which
14. washwashed with saturated aqueous NaHCO3 (100 mL), brine (100 mL), and H2O (100 mL)
15. dry with materialThe organic layer was dried (MgSO4)
16. filtrationfiltered
17. concentrationconcentrated
18. customto give a brown oil
19. customThe oil was purified on 60 g flash SiO2 (9:1 petroleum ether-CH2Cl2)