反应详情

To a solution of 2a (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 (0.90 g, 86.4%). mp: 212°-214° C.; IR(KBr) νmax : 1766, 1717, 1620; UV(CHCl3) νmax (log ε): 306 (3.89), 277 (4.10), 266 (4.14); 1H-NMR (CDCl3): δ3.33 (dt, 1H, 4'-H), 3.66 (dt, 1H, 4'-H), 4.26, 4.32 (two d, 2H, OCH2), 5.60 (s, 1H, 3-H), 5.79 (t, 1H, vinylic H), 6.42 (t, 1H, vinylic H), 7.20-7.61 (m, 9H, 5,6,7,8-H, and aromatic H). Anal. Calcd for C21H16O5 0.25H2O: C, 71.48; H, 4.71. Found: C, 71.37; 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