Br[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[CH2:8][CH2:9][CH2:10][CH:11]=[CH2:12].[B:13](OC(C)C)([O:18]C(C)C)[O:14]C(C)C.N#N.C([Li])CCC>C1(C)C=CC=CC=1.C1COCC1>[CH2:8]([C:3]1[CH:4]=[CH:5][CH:6]=[CH:7][C:2]=1[B:13]([OH:18])[OH:14])[CH2:9][CH2:10][CH:11]=[CH2:12]This compound was prepared according to the procedure described by Watson, I.D.G.; Ritter, S.; Toste, F.D. J. Am.Chem.Soc. 2009, 131, 2056-2057. 1-Bromo-2-(pent-4-en-1-yl)benzene (480 mg, 2.132 mmol) was dissolved in a mixture of toluene (8 mL) and THF (2 mL). Then triisopropyl borate (0.490 mL, 2.132 mmol) was added. While under N2 atmosphere, the reaction mixture was cooled to −78° C. Using a manual syringe, n-butyllithium (0.853 mL, 2.132 mmol)(2.5 M in hexanes) was added dropwise over the course of 30 min. The resulting nearly colorless solution was stirred at −78° C. for 60 min and then at −20° C. for 15 min. The reaction was quenched with 10 mL of 2 N HCl and allowed to stir to warm to rt. The aqueous layer was extracted with ether. The organic phase was dried (Na2SO4), filtered, and concentrated in vacuo. Biotage purification eluting with 5-50% EtOAc/hexanes gave the desired product (65 mg, 0.342 mmol, 16.04% yield) as an off-white solid. 1H NMR (500 MHz, CDCl3) δ 8.27-8.18 (m, 1H), 7.51 (td, J=7.5, 1.4 Hz, 1H), 7.36-7.31 (m, 2H), 5.90-5.80 (m, 1H), 5.04-4.91 (m, 2H), 3.26-3.18 (m, 2H), 2.18 (q, J=6.9 Hz, 2H), 1.83 (dt, J=15.3, 7.7 Hz, 2H).
Loading…
