| 摘要 |
NEW MATERIAL:A compound of formula I (X<1>, X<2> are Cl, Br; R is H, acyl, sulfonyl, alkyl). EXAMPLE:5,5-Dichloro-6,6,6,-trifluoro-2-methyl-2-hexene-4-ol. USE:A synthetic intermediate of 2,2-dimethyl-3-(2-chloro-3,3,3-trifluoro-1-propenyl) cyclopr-opanecarboxylic acid or its esters, which are used as fluorine-containing pyrethroid insecticides and their synthetic intermediates. PREPARATION:For example, the reaction of 3-methyl-2-butenal with 1,1,1- trihalotrifluoroethane is carried out in the presence of zinc dust to give the compound of formula I where R is H. The product is allowed to react with an acylating, sulfonylating or alkylating agent to give a corresponding compound of formula I.
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