Reaction Steps
To a round bottom flask were added 5-fluorosalicylaldehyde (47c, 4.0 g, 28.5 mmol, 1.0 equiv.), potassium carbonate (4.92 g, 35.6 mmol, 1.25 equiv.), and DMF (20 mL). Allyl bromide (3.7 mL, 42.8 mmol, 1.5 equiv.) was added slowly to the mixture. The reaction mixture was stirred overnight at room temperature. The reaction mixture was diluted with water (50 mL) and extracted with ethyl acetate (3×50 mL). The combined organic layers were washed with water (2×25 mL), 0.1M KOH (2×25 mL), water (2×25 mL), and brine (2×25 mL), dried over MgSO4, filtered, and concentrated to yield 53b (4.64 g, 90.2%) as a pale yellow liquid. 1H-NMR (500 MHz, CDCl3) δ 10.47 (d, 1H, J=3.0 Hz), 7.50 (dd, 1H, J=3.0, 8.0 Hz), 7.23 (ddd, 1H, J=3.0, 7.5, 11.0 Hz), 6.95 (dd, 1H, J=4.0, 9.0 Hz), 6.06 (tdd, 1H, J=5.0, 10.5, 17.5 Hz), 5.44 (qd, 1H, J=1.5, 17.0 Hz), 5.34 (ddd, 1H, J=1.5, 2.5, 10.5 Hz), 4.64 (td, 2H, J=1.5, 5.0 Hz). 13C-NMR (125 MHz, CDCl3) δ 188.8, 157.4 (d, JC-F=1.9 Hz), 157.2 (d, JC-F=240.5 Hz), 132.4, 126.1 (d, JC-F=5.9 Hz), 122.6 (d, JC-F=23.8 Hz), 118.5, 114.8 (d, JC-F=7.1 Hz), 114.2 (d, JC-F=23.1 Hz), 70.1. 19F-NMR (470 MHz, CDCl3) δ −125.5. HRMS (EI): 180.05789 (M+); calcd. for C10H9FO2: 180.05866.
