反应详情

2-Bromo-1-(1-bromo-cyclopentyl)-ethanone (3.7 g, 13.7 mmol) and α-picoline (1.02 g, 11.0 mmol) in acetone were heated at reflux overnight. The reaction mixture was allowed to cool then concentrated in vacuo. The crude mass was washed with 30% ethyl acetate/petroleum ether and diethyl ether. 1-(2-Cyclopent-1-enyl-2-oxo-ethyl)-2-methyl-pyridinium bromide salt (3.65 g, 94%) was obtained as a semi-solid material and taken for next step without purification.

1. temperatureat reflux overnight
2. temperatureto cool
3. concentrationthen concentrated in vacuo
4. washThe crude mass was washed with 30% ethyl acetate/petroleum ether and diethyl ether