| 摘要 |
<p>ADSTRACT OF THE DISCLOSURE A novel process for producing a .beta.-dihalogeno-ethenyleyclopropane derivative of the formula, wherein R? is a hydrogen atom or an alkyl group, R3 is a hydrogen atom, lower alkyl, acyl, carboxyl or alkoxycarbonyl group and R is a hydrogen atom or a lower alkyl group and each of Y1 and Y2 is a fluorine, chlorine or bromine atom respectively, which is an acidic moiety of the useful synthetic insecticides of the pyrethrin type, which process comprises a combination of a series of sequential stops starting from alkyl 3-butenyl ketone derivative of the formula (I), which may be shown according to the following reaction scheme: According to this process, objective compound of the formula (VI) having any cis/trans ratio can be produced by selecting the reaction condition of the Stages II-1, II-2 and IV-2.</p> |
