Diisobutylaluminum hydride → HCID 71061309, Verbindung

To a solution of methyl 2-bromo-6,7-dihydro-5H-benzo[7]annulene-8-carboxylate from step A4 (170 mg, 0.605 mmol) in diethyl ether (2 mL) and THF (1 mL) was added 1.0 M DIBAL-H/hexanes (0.726 mL, 0.726 mmol) at −78° C. The mixture was stirred at rt for 16 h. Another 0.726 mL portion of DIBAL-H was added at 0° C., and the mixture was stirred at rt for an additional 2 h. The reaction mixture was diluted with 50 mL of diethyl ether, quenched with water, and extracted with EtOAc (100 mL). The organic layer was dried over sodium sulfate, filtered, and concentrated to give (2-bromo-6,7-dihydro-5H-benzo[7]annulen-8-yl)methanol (150 mg, 0.593 mmol, 98% yield). 1H NMR (500 MHz, chloroform-d) δ 7.30 (s, 1H), 7.22 (dd, J=7.9, 1.8 Hz, 1H), 6.98 (d, J=7.9 Hz, 1H), 6.45 (s, 1H), 4.21 (br. s., 2H), 2.81-2.71 (m, 2H), 2.34 (t, J=6.4 Hz, 2H), 2.08-1.98 (m, 2H).