Under nitrogen atmosphere, sodium hydride (136 mg, 60% dispersion in mineral oil, 3.40 mmol) was washed with dry hexane (2 mL); the solvent was removed, and sodium hydride was placed under dry toluene; dimethyl carbonate (1 mL, 12 mmol) was added to the stirred suspension. The mixture was heated at 80 °C, and with continued stirring, compound 9 (300 mg, 1.48 mmol) in toluene (4 mL) was added dropwise in 10 min, and then toluene (10 mL) was added to dilute the mixture. After 4 h at 90 °C, the mixture was cooled to 0 °C, and 0.5 N aqueous HCl (10 mL) was added. Ice water was added, and the aqueous layer was separated and washed three times with Et2O. The organic phase was then washed with saturated aqueous sodium hydrogen carbonate and water, dried (Na2SO4) and evaporated under reduced pressure to give the crude product, which was purified by flash chromatography (hexane/ethyl acetate, 19:1) to obtain 266 mg (69%) of the title product as a yellow oil. 1H NMR δ: 12.45 (s, 1H, enolic OH); 8.00 (d, 1H, J = 7.8, Ar), 7.77 (dd, 1H, J = 1.1, 7.0 Hz, Ar), 7.50 (m, 2H, Ar), 7.20–7.35 (m, 3H, Ar), 7.15 (d, 1H, J = 7.0 Hz, Ar), 3.82 (s, 3H, -OCH3), 3.78 (s, 3H, -OCH3), 3.38 (d, 1H, J = 10.4 Hz), 2.99 (dd, 1H, J = 4.1, 16.4 Hz, -CH2CH<,), 2.97 (m, 2H, -CH2CH<), 2.80 (m, 1H, CH2CH<), 2.75 (m, 1H, -CH2CH<), 2.57 (m, 1H, -CH2CH<), 1.37 (m, 6H+6H, -(CH2)3CH3 ketone+enol), 0.89 (m, 3H+3H, -CH3 ketone+enol). Anal. Calcd for C16H20O3: C, 73.82; H, 7.74. Found: 73.91; H, 7.69.