- Assignment of absolute configurations of permethrin and its synthon 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid by electronic circular dichroism, optical rotation, and X-ray crystallography
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The availability of single stereoisomers of biologically/toxicologically relevant chiral compounds such as the pyrethroid-type insecticide permethrin (PM) and the reliable determination of their absolute configurations are of central importance for the de
- Bicker, Wolfgang,Kacprzak, Karol,Kwit, Marcin,Laemmerhofer, Michael,Gawronski, Jacek,Lindner, Wolfgang
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- Search for Routes of Synthesis of Permethrin and Chloropermethrin Starting from Halogen-containing Alkenoic Acids
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Promising procedures were developed for the synthesis of permethrin and I-chloropermethrin starting from acid chloride, nitrile, and esters of 3,3-dimethyl-2,2,4,6,6-pentachloro-5-alkenoic acid and 3,3-dimethyl-2,2,6,6-tetrachloro-5-alken-4-olide, which were prepared by adding derivatives of trichloroacetic acid to 1,1-dichloro-4-methyl-1,3-pentadiene in the presence of catalytic amounts of monovalent copper ions and amine.
- Badanyan,Stepanyan,Mikaelyan,Ovivyan,Panosyan
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- Ester synthesis
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A novel process is described for the preparation of compounds of formula STR1 wherein R2 and R3 are each chloro or bromo; X is carboxyl, nitrile, optionally substituted carbonamide, carbonyl halide or an ester group. Those compounds wherein X is an appropriate ester group --COOB where B is an aryl group such as m-phenoxybenzyl are known insecticides; compounds where X is other than --COOB may be suitably converted thereto. The novel process consists of a series of steps from the corresponding acetyl compound of formula STR2 which comprises halogenation, reduction, esterification and finally elimination reactions.
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