General method: To a stirred solution of 1,6-dibromohexane (1 eq.) in anhydrous tetrahydrofuran (THF, 0.1 M) was added potassium tert-butoxide (tert-BuOK, 1.15 eq.) in batches over a period of 30 min under argon protection. The reaction mixture was stirred under reflux conditions for 16 h before being cooled to room temperature and subsequently quenched with deionized water. The resulting mixture was diluted with diethyl ether and the organic and aqueous layers were separated. The aqueous layer was extracted several times with diethyl ether, all organic layers were combined, washed with saturated brine, dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The crude product was purified by silica gel fast column chromatography with petroleum ether as eluent to obtain the target product 6-bromo-1-hexene.
2.3.1 Synthesis of 6-bromo-1-hexene
6-Bromo-1-hexene was synthesized from 1,6-dibromohexane (8.1 g, 33.6 mmol) according to the general method described above. Yield: 4.3 g (79% yield) as a colorless oil. Thin layer chromatography (TLC) Rf value: 0.71 (100% hexane unfolding, potassium permanganate solution color development).
1H NMR (CDCl3, 500MHz, ppm): δ5.79 (ddt, J = 17.0, 10.2, 6.7Hz, 1H), 5.02 (ddd, J = 17.1, 3.5, 1.6Hz, 1H), 4.97 (ddt, J = 10.2, 2.2, 1.2 Hz, 1H), 3.41 (t, J = 6.8 Hz , 2H), 2.13 - 2.05 (m, 2H), 1.92 - 1.83 (m, 2H), 1.54 (tt, J = 9.3, 6.6 Hz, 2H).
13C NMR (CDCl3, 126MHz, ppm): δ 138.27, 115.14, 33.87, 32.95, 32.29, 27.48.
