反应详情

9.65 g (111 mmol) of manganese dioxide were added to a solution of 6.5 g (31.7 mmol) of 3-bromo-4-fluorobenzyl alcohol and 13.25 g (38 mmol) of ethoxycarbonylmethylenephosphorane in 390 ml of toluene. The reaction mixture was heated at reflux, a further 9.65 g of manganese dioxide were added after 1 h and heating under reflux was continued overnight. After cooling, the mixture was filtered through celite and the filtrate was concentrated. The residue was purified by flash chromatography on silica gel (mobile phase cylclohexane/ethyl acetate 5:1). This gave 7.05 g (81% of theory) of the target product in the form of an E/Z isomer mixture.

1. temperatureThe reaction mixture was heated
2. temperatureat reflux
3. temperatureheating
4. temperatureunder reflux
5. temperatureAfter cooling
6. filtrationthe mixture was filtered through celite
7. concentrationthe filtrate was concentrated
8. customThe residue was purified by flash chromatography on silica gel (mobile phase cylclohexane/ethyl acetate 5:1)