反应详情

To a solution of 4a (0.84 g, 3 mmol) in dry tetrahydrofuran (60 ml) were added activated zinc powder (0.255 g, 3.9 mmol), hydroquinone (6 mg), and ethyl 2-(bromomethyl)acrylate (0.78 g, 4 mmol). The mixture was refluxed under nitrogen atmosphere for 18 h. (monitored by TLC). After cooling it was poured into an ice-cold 5% HCl solution (300 ml) and extracted with CH2Cl2 (75 ml×3). The dichloromethane extracts were combined and washed with saline, dried over Na2SO4, and then evaporated to give a residual solid which was crystallized from ethyl acetate to afford the title compound; Yield: 77.8%; mp: 105°-106° C.; IR(KBr) νmax : 1758, 1719, 1616; UV(CHCl3) λmax (log ε): 321 (4.22), 243 (3.62); 1H-NMR (CDCl3): δ3.24 (dt, 1H, 4'-H), 3.66(dt, 1H, 4'-H), 4.17, 4.24 (two d, 2H, OCH2), 5.71 (t, 1H, vinylic H), 6.24 (d, 1H, 3-H), 6.31 (t, 1H, vinylic H), 6.72 (d, 1H, 8-H), 6.78 (dd, 1H, 6-H), 7.35 (d, 1H, 5-H), 7.40-7.52 (m, 5H, aromatic H), 7.62 (d, 1H, 4-H). Anal Calcd for C21H16O5:C, 72.41; H, 4.63. Found: C, 72.30; H, 4.67.

1. temperatureThe mixture was refluxed under nitrogen atmosphere for 18 h. (monitored by TLC)
2. temperatureAfter cooling it
3. extractionextracted with CH2Cl2 (75 ml×3)
4. washwashed with saline
5. dry with materialdried over Na2SO4
6. customevaporated
7. customto give a residual solid which
8. customwas crystallized from ethyl acetate