反应详情

A solution of 12.3 g (0.11 mol) of potassium tert.-butylate in 30 ml of dimethylformamide was added dropwise, under an inert gas atmosphere (nitrogen or argon) at -20° to -25° C., to a solution of 24 g (0.180 mol) of dichloromethane-phosphonic acid diethyl ester and 14 g (0.1 mol) of 2-acetyl-3,3-dimethylcyclopropanecarboxaldehyde in 100 ml of tetrahydrofuran. The mixture was subsequently stirred for 3 hours without cooling, 200 ml of water were added and extraction was carried out twice with 100 ml of methylene chloride. The organic phase was washed with 50 ml of 10% strength sodium hydroxide solution and then with 3 times 50 ml of water, dried over sodium sulphate and evaporated in vacuo. 14.8 g (71% of theory) of 1-(2,2-dichlorovinyl)-2-acetyl-3,3-dimethylcyclopropane were obtained from the residue, by vacuum distillation, in the form of a pale yellow oil having a boiling point of 55°-57° C./0.3 mbar.

1. temperaturewithout cooling
2. extractionextraction
3. washThe organic phase was washed with 50 ml of 10% strength sodium hydroxide solution
4. dry with materialwith 3 times 50 ml of water, dried over sodium sulphate
5. customevaporated in vacuo