Hydroquinone → 7-((2-Methyl-4-methylene-5-oxotetrahydro-2-furanyl)methoxy)-2H-chromen-2-one

関与物質

反応手順

To a solution of 3a (0.655 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 reflued under nitrogen atmosphere for 36 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: 79.7%; mp: 123°-124° C.; IR(KBr) νmax : 1755, 1727, 1626; UV(CHCl3) λmax (log ε): 312 (4.18), 243 (3.58); 1H-NMR (CDCl3): δ1.58 (s, 3H, 5'-CH3), 2.79 (dt, 1H, 4'-H), 3.18 (dt, 1H, 4'-H), 3.99, 4.09 (two d, 2H, OCH2), 5.69 (t, 1H, vinylic H), 6.26 (d, 1H, 3-H), 6.29 (t, 1H, vinylic H), 6.76-6.84 (m, 2H, 6 and 8-H). 7.38 (d, 1H, 5-H), 7.65 (d, 1H, 4-H). Anal Calcd for C16H14O5 : C, 67.13; H, 4.93. Found: C, 66.95; H. 5.10.

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