Reaction Steps
A round bottom flask containing 56 (201 mg, 0.75 mmol) in dry ether (6 mL) was immersed in a 25° C. water bath. n-BuLi (1.5 M in THF, 602 μL, 0.90 mmol) was added via syringe pump over one hour, generating an orange solution. Following addition of base, the reaction mixture was stirred at 25° C. for an additional 1.5 hours and then cooled to −78° C. TMSCl (200 μL, 1.58 mmol) was added rapidly via syringe, and the reaction mixture was stirred an additional 5 minutes at −78° C., then warmed to room temperature over 3.5 hours. The reaction was subsequently diluted with ether, filtered, and concentrated in vacuo. Crude product was purified by flash column chromatography (20:1 hexanes-ethyl acetate) to yield 57 as a solid in 62% yield (159 mg, 0.47 mmol). 1H NMR (600 MHz, CDCl3): δ 7.54 (d, 1H, J=8.4 Hz), 7.39-7.41 (dd, 1H, J=8.4, 4.8 Hz), 7.33-7.35 (dd, 1H, J=9, 2.4 Hz), 6.83-6.89 (m, 3H), 3.98 (s, 3H), 3.93 (s, 3H), −0.02 (s, 9H). 13C NMR (150 MHz, CDCl3): δ 61.4 (d, J=238.5 Hz), 156.2, 144.5 (d, J=2.0), 143.0, 141.5 (d, J=3 Hz), 134.8 (d, J=9.5 Hz), 125.4, 124.79 (d, J=9.15 Hz), 120.9, 118.0, 109.4 (d, J=22.8 Hz), 108.6, 103.9 (d, J=24.3 Hz), 93.5, 5.6, 36.3, 31.0, −2.5; 19F NMR (CD3CD, 376 MHz): δ −117.6 (m); FTIR: cm−12952, 1608, 1523, 1372, 1223, 1163, 1107, 1042, 939, 841.
