Reaction Steps
4,5,6,7-Tetrahydrofuro[3,2-c]pyridine (0.47 g, 3.82 mmol), 8-bromo-8-(2-chlorophenyl)-2,2-dimethyloctanoic acid ethyl ester (1.47 g, 3.78 mmol) in DMF (36 mL), and potassium carbonate (0.77 g, 5.58 mmol) were combined under an argon atmosphere at room temperature. The mixture was heated to 60° C. for 3 days under argon atmosphere, monitored by TLC. The DMF was evaporated under reduced pressure and the residue was dissolved in diethyl ether (120 mL), washed with water (3×30 mL), brine (30 mL), and dried over Na2SO4. The crude oil was purified by column chromatography (silica gel, ethyl acetate/heptane 1/9) to afford pure 8-(2-chlorophenyl)-8-(6,7-dihydro-4H-furo[3,2-c]pyridin-5-yl)-2,2-dimethyloctanoic acid ethyl ester (Compound Ip, 0.50 g, 30.3% yield) as a yellow oil. 1H NMR (Field: 300 MHz, Solvent: CD3OD/TMS) δ (ppm): 7.48 (d, 1H, J=7.5 Hz), 7.36 (d, 1H, J=7.8 Hz), 7.32-7.15 (m, 3H), 6.17 (s, 1H), 4.20 (dd, 1H, J=9.0, 4.8 Hz), 4.08 (q, 2H, J=7.2 Hz), 3.62 (d, 1H, J=13.5 Hz), 3.11 (d, 1H, J=13.5 Hz), 2.88-2.58 (m, 4H), 1.95-1.70 (m, 2H), 1.45-1.40 (m, 2H), 1.30-1.0 (m, 15H). 13C NMR (Field: 75 MHz, Solvent: CDCl3/TMS) δ (ppm): 178.01, 149.01, 140.94, 139.50, 135.00, 129.57, 129.04, 128.03, 126.85, 115.92, 108.90, 63.43, 60.36, 47.65, 47.54, 42.36, 40.91, 33.27, 30.57, 25.67, 25.41, 25.06, 24.73, 14.55. HRMS (HR, DART-TOF): Calculated for (M+H)+: 432.2300, found 432.2316.
