- 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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experimental part
p. 1027 - 1035
(2009/10/10)
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- Practical method for crystalline-liquid resolution of chrysanthemic acids utilizing chiral 1,1′-binaphthol monoethyl ethers directed for process chemistry
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We have developed an efficient practical resolution method for (1R,3R)-trans-chrysanthemic acid 1 and (1R,3S)-trans-2,2-dimethyl-3-(2,2-dichloroethenyl)cyclopropanecarboxylic acid 2, based on the preliminary results of the simpler analogues, (1R)-2,2-dichlorocyclopropanecarboxylic acid 3 and (1R)-2,2-dimethylcyclopropanecarboxylic acid 4, using a crystalline-liquid separation procedure (without column chromatography) with chiral 1,1′-binaphthol monoethyl ethers (R)-5b as the key auxiliary. Direct esterifications of 1, 2, 3, and 4 with (R)-5b gave four sets of (1R)- and (1S)-diastereomeric esters 8, 9, 6, and 7, respectively, with markedly different melting points. All of these diastereomers were easily obtained using a simple and one-step crystalline-liquid separation. The separated diastereomers 8 and 9 were easily hydrolyzed to the desired enantiopure acids 1 (>98%) and 2 (>99%), respectively, with recovery of (R)-5b (>90%).
- Atago, Takayuki,Tanaka, Akihiro,Kawamura, Tomoyuki,Matsuo, Noritada,Tanabe, Yoo
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experimental part
p. 1015 - 1019
(2009/09/30)
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- Molecular cloning, purification, and biochemical characterization of a novel pyrethroid-hydrolyzing esterase from Klebsiella sp. strain ZD112
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The gene encoding pyrethroid-hydrolyzing esterase (EstP) from Klebsiella sp. strain ZD112 was cloned into Escherichia coli and sequenced. A sequence analysis of the DNA responsible for the esfP gene revealed an open reading frame of 1914 bp encoding for a protein of 637 amino acid residues. No similarities were found by a database homology search using the nucleotide and deduced amino acid sequences of the esterases and lipases. EstP was heterologously expressed in E. coli and purified. The molecular mass of the native enzyme was approximately 73 kDa as determined by gel filtration. The results of sodium dodecyl sulfate - polyacrylamide gel electrophoresis and the deduced amino acid sequence of EstP indicated molecular masses of 73 and 73.5 kDa, respectively, suggesting that EstP is a monomer. The purified EstP not only degraded many pyrethroid pesticides and the organophosphorus insecticide malathion, but also hydrolyzed ρ-nitrophenyl esters of various fatty acids, indicating that EstP is an esterase with broad substrates. The Km for trans- and cis-permethrin and kcat/Km values indicate that EstP hydrolyzes both these substrates with higher efficiency than the carboxylesterases from resistant insects and mammals. The catalytic activity of EstP was strongly inhibited by Hg2+, Ag+, and ρ-chloromercuribenzoate, whereas a less pronounced effect (3-8% inhibition) was observed in the presence of divalent cations, the chelating agent EDTA, and phenanthroline.
- Wu, Pei C.,Liu, Yu H.,Wang, Zhuo Y.,Zhang, Xiao Y.,Li, He,Liang, Wei Q.,Luo, Na,Hu, Ji M.,Lu, Jia Q.,Luan, Tian G.,Cao, Li X.
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p. 836 - 842
(2007/10/03)
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- Purification and characterization of a novel pyrethroid hydrolase from Aspergillus niger ZD11
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The pyrethroid pesticides residues on foods and environmental contamination are a public safety concern. Pretreatment with pyrethroid hydrolase has the potential to alleviate the conditions. For this purpose, a fungus capable of using pyrethroid pesticides as a sole carbon source was isolated from the soil and characterized as Aspergillus niger ZD11. A novel pyrethroid hydrolase from cell extract was purified 41.5-fold to apparent homogeneity with 12.6% overall recovery. It is a monomeric structure with a molecular mass of 56 kDa, a pl of 5.4, and the enzyme activity was optimal at 45°C and pH 6.5. The activities were strongly inhibited by Hg2+, Ag+, and p-chloromercuribenzoate, whereas less pronounced effects (5-10% inhibition) were observed in the presence of the remaining divalent cations, the chelating agent EDTA and phenanthroline. The purified enzyme hydrolyzed various insecticides with similar carboxylester. trans-Permethrin is the preferred substrate.
- Liang, Wei Q.,Wang, Zhuo Y.,Li, He,Wu, Pei C.,Hu, Ji M.,Luo, Na,Cao, Li X.,Liu, Yu H.
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p. 7415 - 7420
(2007/10/03)
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- Development of pyrethroid substrates for esterases associated with pyrethroid resistance in the tobacco budworm, Heliothis virescens (F.)
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Assays to detect esterases associated with resistance to organophosphorus and pyrethroid insecticides in larvae of H. virescens were developed and evaluated. Cross-resistance to a variety of insecticides was measured in strains resulting from selection with either profenofos (OP-R) or cypermethrin (PYR-R), and resistance in both strains appeared to have a metabolic component. Esters were synthesized that coupled 3-(2,2-dichlorovinyl)-2,2- dimethylcyclopropanecarboxylate, the acid moiety of some pyrethroid insecticides, with groups (e.g., p-nitrophenyl-) that could be detected spectrophotometrically following hydrolysis of the resulting esters. Activities toward these pyrethroid esters were significantly higher in both resistant strains than those in a susceptible reference strain. In addition, all pyrethroid esters significantly increased the toxicity of cypermethrin in bioassays with larvae from both PYR-R and OP-R strains. The biological and biochemical activities of these compounds are compared with those with more conventional esterase substrates and insecticide synergists, and the utility of pyrethroid esters as components of rapid assays for detecting esterases associated with insecticide resistance is discussed.
- Huang, Huazhang,Ottea, James A.
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p. 6539 - 6545
(2007/10/03)
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- Nitrile biotransformation for highly enantioselective synthesis of 3-substituted 2,2-dimethylcyclopropanecarboxylic acids and amides
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Biotransformations of differently configured 2,2-dimethyl-3-substitued-cyclopropanecarbonitriles were studied using a nitrile hydratase/amidase-containing Rhodococcus sp. AJ270 whole-cell catalyst under very mild conditions. Although all of the cis-3-aryl-2,2-dimethylcyclopropanecarbonitriles appeared inert toward the biocatalyst, a number of racemic trans-isomers efficiently underwent a highly enantioselective hydrolysis to produce (+)-(1R,3R)-3-aryl-2,2-dimethylcyclopropanecarboxylic acids and (-)-(1S,3S)-3-aryl-2,2-dimethylcyclopropanecarboxamides in high yields with excellent enantiomeric excesses in most cases. The overall enantioselectivity of the biotransformations of nitriles originated from the combined effects of 1R-enantioselective nitrile hydratase and amidase, with the later being a dominant factor. The influence of the substrates on both reaction efficiency and enantioselectivity was discussed in terms of steric and electronic effects. Coupled with chemical transformations, biotransformations of nitriles provided convenient syntheses of optically pure geminally dimethyl-substituted cyclopropanecarboxylic acids and amides, including chrysanthemic acids, in both enantiomeric forms.
- Wang, Mei-Xiang,Feng, Guo-Qiang
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p. 621 - 624
(2007/10/03)
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- Free radical addition of haloalkanes to polymer bound olefins and its application to the solid-phase synthesis of pyrethroids
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Polymer bound olefins undergo free radical initiated 1,2-addition when reacted with a variety of haloalkanes. The strategy could be applied successfully to the solid-phase synthesis of dihaloethenylcyclopropane carboxylic acids which are the key fragments of synthetic pyrethroids.
- Kumar,Chakravarthy, P.Pawan,Shesha Rao,Reddy, P.Sunder Ram,Yadav
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p. 7817 - 7819
(2007/10/03)
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- An efficient and selective conversion of hydrazides into esters and acids
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Hydrazides are selectively oxidised to esters/acids in high yields using Oxone in the presence of an appropriate alcohol/water as a nucleophile at ambient temperature. A variety of functional groups including alkenes, alcohols, ethers, cyclopropyl groups and nitriles are unaffected.
- Srinivas,Subba Reddy,Yadav,Ramalingam
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p. 376 - 377
(2007/10/03)
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- Enzyme catalysed kinetic resolution of racemic 2,2-dimethyl-3-(2,2- disubstituted vinyl) cyclopropane carboxylic acids anchored on polymer supports
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Kinetic resolution of trans-substituted cyclopropane carboxylic acids anchored on a solid support by lipase is described.
- Nanda,Bhaskar Rao,Yadav
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p. 5905 - 5908
(2007/10/03)
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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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- Biological Activity of Pyrethroid Analogs in Pyrethroid-Susceptible and -Resistant Tobacco Budworms, Heliothis virescens (F.)
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The phenoxybenzyl moiety of conventional pyrethroids is a major site of oxidative metabolism in resistant tobacco budworms, Heliothis virescens (F.). In this study, this group was replaced with known P450 monooxygenase-inhibiting or oxidatively blocked groups. A variety of isomers (1R/1S, cis/trans) of the resulting chrysanthemates were tested as insecticides or synergists against tobacco budworms that were insecticide-susceptible (LSU) or that expressed metabolic resistance to cypermethrin (Pyr-R). A number of compounds with pentafluorophenyl, methylenedioxyphenyl, and propargyloxyphenyl groups were insecticidal, and activity was dependent on both geometric and stereochemical configuration of the acid moiety. Both trans and cis isomers of 1(R)-fenfluthrin, which contains a pentafluorophenyl group, suppressed resistance to cypermethrin in Pyr-R insects, confirming that oxidative metabolism of the phenoxybenzyl moiety is a major mechanism of resistance in this strain. Of the methylenedioxyphenyl compounds, 1R, trans, and cis isomers were toxic and partially suppressed resistance in Pyr-R larvae. Similarly, both trans and cis isomers of α(S),1(R)-propargyloxyphenyl-containing compounds were insecticidal. Finally, α(R),1(R)-cis-methylenedioxyphenyl- and -propargyloxyphenyl- containing compounds were nontoxic but significantly enhanced toxicity of cypermethrin.
- Shan, Guomin,Hammer, Robert P.,Ottea, James A.
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p. 4466 - 4473
(2007/10/03)
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- Structural Studies on Optical Resolution via Diastereoisomeric Salt Formation, Part 2. The Conformational Flexibility of (S)-2-Benzylaminobutan-1-ol in Enantiomer Separation for Permethrinic Acids
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The optical resolution of trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid (1) with (S)-2-benzylaminobutanol (2) has been optimized.Thermodynamic constants, thermal behaviour, and the crystal structures of the diastereoisomeric salts were determined in order to evaluate the results of optical resolution.The resolving agent (2) exists in four different conformations in the diastereoisomeric salts of (1) and its cis isomer.The relative energies of these four rotamers have been studied by means of force-field calculations.
- Simon, Kalman,Kozsda, Eva,Boecskei, Zsolt,Faigl, Ferenc,Fogassy, Elemer,Reck, Guenther
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p. 1395 - 1400
(2007/10/02)
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- Investigation of Readily Available Chiral Compounds for Preparative Scale Resolutions
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Diastereoisomeric esters were formed by reaction of racemic carboxylic acids with the readily available hydroxy lactone derivatives, 2,3-O-isopropylidene-D(+)-ribono-1,4-lactone, D(-)-2-hydroxy-3,3-dimethylbutyro-1,4-lactone (D(-)-pantolactone) and 1,2-O-isopropylidene-(+)-a-D-glucofuranurono-6,3-lactone.In all cases separation of the diastereoisomeric esters was achieved by crystallization and/or chromatography.Purity of the diastereoisomers could be determined by h.p.l.c. or by 1H n.m.r.Hydrolysis under mild basic conditions followed by treatment with acid gave optically pure carboxylic acids.The facile separation by crystallization and/or chromatography of diastereoisomers prepared from racemic endo-1,4,5,6,7,7-hexachlorobicyclohept-5-ene-2-carboxylic acid suggested that the resolved acid may be useful as a resolving agent.This was shown by separation of diastereoisomers formed from the resolved acid and racemic 1-(3'-phenoxyphenyl)prop-2-yn-1-ol and racemic 1-cyano-1-(3'-phenoxyphenyl)methanol respectively.Optically pure 1-(3'-phenoxyphenyl)prop-2-yn-1-ol was obtained by hydrolysis of the separated diastereoisomers.
- Duke, Colin C.,Wells, Robert J.
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p. 1641 - 1654
(2007/10/02)
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- EFFECT OF MOLECULAR STRUCTURE ON STEREOSELECTIVITY DURING THE HYDROLYSIS OF DIASTEREOISOMERIC PERMETHRINIC ACID ESTERS
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Chemical behaviour and thermal stability differences between the diastereoisomeric cis- and trans-permethrines are elucidated on the basis of their crystal structures.Crystals of the trans-isomer are monoclinic with space group C2/c, with 8 molecules in a unit cell of dimensions a = 38.030(5), b = 9.163(2), c = 11.715(6) Angstroem and B = 105.95(4).Previously published cis-structures are reinvestigated in order to obtain the same accoracy for both derivatives.
- Simon, Kalmal,Boros, Iren,Balogh, Gyula,Hidasi, Gyeorgy,Fogassy, Elemer,et al.
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p. 111 - 124
(2007/10/02)
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- A Convenient Synthesis of Ethyl 3-(2,2-Dihaloethenyl)-2,2-dimethylcyclopropanecarboxylates and Its Modifications for cis-Isomer Enrichment
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A synthesis of the title compounds 5 involves the reaction between 3-methyl-2-buten-1-ol and triethyl orthoacetate to produce ethyl 3,3-dimethyl-4-pentenoate, which is followed by the addition of various carbon tetrahalides to the double bond.The reaction of resulting adducts with a base affords 5 in high yields.Stereoselective preparation of the cis-isomer was achieved by the following two methods: First one involves selective transformation of ethyl 4-bromo-6,6,6-trichloro-3,3-dimethylhexanoate to ethyl 6,6,6-trichloro-2,3-dimethyl-4-hexanoate (8a) with piperidine followed by the selective conversion of 8a to cis-2,2-dichloroethenyl compound (cis-5a).Second one is based on the stereoselective cyclization of ethyl 4,6,6,6-tetrachloro-3,3-dimethyl-hexanoate (t-BuONa/solvent/HMPA) to ethyl cis-2,2-dimethyl-3-(2,2,2-trichloroethyl)cyclopropanecarboxylate which is transformed into cis-5a without cis-trans isomerisation.
- Matsui, Kiyohide,Negishi, Akira,Takahatake, Yuriko,Sugimoto, Kikuo,Fujimoto, Tamotsu,et al.
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p. 221 - 228
(2007/10/02)
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- Carboxylic acid ester derivatives, process for manufacturing said derivatives, insecticides and acaricides containing said derivatives, and method for killing insects and acarina by treating therewith
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Novel carboxylic acid ester derivatives, of the formula (I): STR1 process for manufacturing said derivatives, insecticides and acaricides containing said derivatives, and a method for killing insects and acarina by treating therewith.
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- Dependence of the Stereoselectivity on the Leaving Group, the Temperature and the Solvent in the Favoskii-Reaction of Enolisable Cyclobutanones
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The based-induced contraction of enolisable 2-halocyclobutanones is often not stereoselectiv.The cis/trans-isomer ratio in the cyclopropanecarboxylic acid 9 derived from 2,4-cis-substituted cyclobutanones 7 depends on the nature of the leaving group.In addition, the choice of the base, the temperature and the solvent can profoundly affect the stereoselectivity of the Favoskii-reaction.The use of the p-bromophenylsulfonyloxy group as leaving group and an inhomogenous reaction medium leads exclusively to cis-carboxylic acid.
- Martin, Pierre
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p. 1189 - 1199
(2007/10/02)
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- Resolution of D,L-cis and D,L-trans 2,2-dimethyl-3-(2,2-dihalovinyl)-cyclopropane-1-carboxylic acids and salts thereof
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A novel process for the resolution of D,L-cis and D,L-trans 2,2-dimethyl-3-(2,2 -dihalovinyl)-cyclopropane-1-carboxylic acids of the formula STR1 wherein X is selected from the group consisting of fluorine, chlorine and bromine comprising salifying the said acid with an optically active base selected from the group consisting of D-ephedrine, L-ephedrine, D-N-methyl-ephedrine, L-N-methylephedrine, D-pseudo-ephedrine and L-pseudo-ephedrine to form the corresponding salt, recovering the said salt and subjecting the latter to acid hydrolysis to obtain the corresponding resolved acid which are intermediates for the synthesis of esters having a remarkable insecticidal activity.
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