反应详情

温度

-78 °C

At −78° C., a of solution of bis(cyclopentadienyl)zirconium dichloride (18.68 g, 63.9 mmol) in THF (200 ml) was treated dropwise with a solution of 3M ethylmagnesium bromide in Et2O (42.5 ml). The resulting mixture was stirred for 1 h at −78° C., warmed to 0° C., stirred at 0° C. until the color of the solution turned red, and treated with a solution of 3-methylcyclohex-2-enone (7 g, 63.9 mmol) in THF (100 ml). After 3 h stirring at 20° C., the resulting mixture was concentrated. The residue was dissolved in dichloromethane (300 ml) and treated with TiCl4 (7.0 ml, 63.9 mmol). The resulting mixture was stirred for 20 min. and treated with a saturated aqueous solution of NH4Cl. The aqueous phase was extracted with dichloromethane. The combined organic phases were washed with a saturated aqueous solution of NaHCO3, with a saturated aqueous solution of NaCl, and concentrated. FC (SiO2, pentane) of the crude product (9.53 g) gave 5-methylspiro[2.5]oct-4-ene (3.42 g, 44%).

1. temperaturewarmed to 0° C.
2. stirringstirred at 0° C. until the color of the solution
3. stirringAfter 3 h stirring at 20° C.
4. concentrationthe resulting mixture was concentrated
5. dissolutionThe residue was dissolved in dichloromethane (300 ml)
6. stirringThe resulting mixture was stirred for 20 min.
7. extractionThe aqueous phase was extracted with dichloromethane
8. washThe combined organic phases were washed with a saturated aqueous solution of NaHCO3, with a saturated aqueous solution of NaCl
9. concentrationconcentrated