Syntheses of Pyrethroid Acids

Abstract

In the course of the last decade the chemistry of insecticides was expanded with the discovery of new cyclopropanecarboxylic acid esters of specific structure, far superior in action to the hitherto known insecticides of other substance classes or the natural prototypes from the group of pyrethrum constituents. The discovery quickly precipitated a host of wideranging studies on the synthesis of these compounds. The development of selective methods of synthesizing complicated small rings called for a comprehensive repertoire: thus, synthesis of the compounds on an industrial scale makes use of sigmatropic rearrangement, radical addition, and nucleophilic ring closure with carbanions. These new industrial syntheses have acquired particular topicality because of their use of stereospecific and enantioselective methods.

Synthesis, larvicidal, QSAR and structural studies of some triorganotin 2,2,3,3‐tetramethylcyclopropanecarboxylates

“…Thus, incorporating a triorganotin moiety into fragments of pyrethroids may increase their activities due to synergistic effects. Since insecticidal activity has been reported for esters of 2,2,3,3-tetramethylcyclopropane carboxylic acid, 11 a mimic of the acid part of a pyrethroid, a series of triorganotin 2,2,3,3-tetramethylcyclopropanecarboxylates were synthesized and screened against the Aedes aegypti (Ae. aeypti), Anopheles stephensi (An.…”

Tetrafluorine‐Containing Ketones and Acetoacetates: Synthesis and Mechanistic Study

“…Nevertheless, the reaction between phosphonate 2 and LDA at -78°C could be detected by acylation of the carbanion 3 with propionyl chloride to give the acylated compound 4 which showed a doublet ( 2 J F,P = 76. 4 Si. FTIR spectra were recorded on a Mattson Cygnus 100 FTIR spectrophotometer.…”

Applications of Chiral Three-membered Rings for Total Synthesis: A Review

“…This fact has inspired chemists to find novel approaches for their synthesis [143], and thousands of cyclopropane compounds have already been prepared [144]. In particular, the asymmetric synthesis of cyclopropanes has remained a challenge [2f, 145], since it was demonstrated that members of the pyrethroid class of compounds to be effective insecticides [146]. In the last decade, many important chiral cyclopropane derivatives have been synthesized according to three principal methodologies, including the Simmons-Smith reaction [147], the transition-metal-catalyzed decomposition of diazo compounds [2f, 148], and the Michael-initiated ring-closure (MIRC) [149].…”