Practical, Stereocontrolled Synthesis of Polyfluorinated Artificial Pyrethroids

• Published in: Bulletin of the Chemical Society of Japan Vol. 60; no. 12; pp. 4385 - 4394
• Main Authors: Fujita, Makoto, Kondo, Kiyosi, Hiyama, Tamejiro
• Format: Journal Article
• Language: English
• Published: Tokyo The Chemical Society of Japan 01.12.1987; Chemical Society of Japan
• Subjects: Alicyclic compounds; Alicyclic compounds, terpenoids, prostaglandins, steroids; Chemistry; Exact sciences and technology; Organic chemistry; Preparations and properties; Zinc Organic compounds; Insecticide; Regioselectivity; Geometrical configuration; Zinc; Chemical reduction; Stereoselectivity; Aldehydoester; Halogenation; Acetylation; Fluorine Organic compounds; Monocyclic compound; Ethylenic compound; Diastereomer
• ISSN: 0009-2673; 1348-0634
• DOI: 10.1246/bcsj.60.4385

Practical and stereocontrolled approaches to polyfluorinated synthetic pyrethroids based on aldehyde addition of CF3CCl2ZnCl are described. The zinc reagent was allowed to react with 3-formyl-2,2-dimethylcyclopropanecarboxylates (6) to give the corresponding adducts. These were acetylated and then reduced again with zinc to afford (1R*, 3S*)-3-(2-chloro-3,3,3-trifluoro-1-propenyl)-2,2-dimethylcyclopropanecarboxylates (12). The (1R*, 3R*)-isomer was derived from 2,2-dichloro-1,1,1-trifluoro-5-methyl-4-hexen-3-ol by diazoacetylation, Cu(II)-catalyzed intramolecular carbene addition, and finally by the zinc reduction. An alternative access to 12 and its halogen homologues of the (Z)-pyrethroids involves addition of 1-halo-2,2-difluoroethenyl group across the CHO group of 6 and subsequent regio- and stereoselective halogenation.