反应详情

4-Methyl-1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione (6a, 0.20 g, 0.5 mmol) and palladium on activated carbon (0.25 g, 10%) were combined in ethyl acetate (100 ml). The mixture was placed under a hydrogen atmosphere (60 psi) on a Parr apparatus for 2 hr at room temperature. The resulting mixture was filtered through celite and the solvent evaporated to afford an oil. The crude oil was twice chromatographed on silica gel with ethyl acetate/hexane to give a semi-solid. The crude semi-solid was distilled bulb to bulb to give 80 mg (38%) of a pale yellow oil; 1H NMR: δ enol form: 1.69 (s, 3H), 2.72 (m, 8H), 3.83 (s, 6H), 5.48 (s, 2H), 6.69 (m, 4H), 6.79 (d, 2H, J=7.5 Hz); keto form: 1.23 (d, 3H, J=7.2 Hz), 2.72 (m, 8H), 3.57 (q, 1H, J=7.0 Hz), 3.83 (s, 6H), 5.48 (s, 2H), 6.69 (m, 4H), 6.79 (d, 2H, J=7.5 Hz); 13C NMR: δ 12.5, 29.2, 43.3, 55.9, 61.4, 111.0, 114.2, 120.7, 132.4, 143.9, 146.3, 206.1; Exact mass calcd for C22H26O6: 386.1729, observed (M+H) 387.1783.

1. customfor 2 hr
2. customat room temperature
3. filtrationThe resulting mixture was filtered through celite
4. customthe solvent evaporated
5. customto afford an oil
6. customThe crude oil was twice chromatographed on silica gel with ethyl acetate/hexane
7. customto give a semi-solid
8. distillationThe crude semi-solid was distilled bulb to bulb