- Synthesis and characterization of chrysanthemic acid esters
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A short and convenient synthesis for a series of novel chrysanthemic acid esters from aldehyde and chrysanthemic acid is reported.
- Ding, Qingwei,Li, Yonghong,Zhang, Mingang
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experimental part
p. 2881 - 2883
(2012/08/29)
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- Development of Immunoassays for Type II Synthetic Pyrethroids. 1. Hapten Design and Application to Heterologous and Homologous Assays
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Immunoassays differing in selectivities for pyrethroid insecticides have been developed for the detection of type II pyrethroids, including deltamethrin, cypermethrin, and λ-cyhalothrin. Two approaches were employed in hapten synthesis to raise antibodies with different cross-reactions: (1) use of three spacer attachment points to offset different parts of molecules from the points of attachment and (2) use of linkers with and without bulky groups in the enzyme conjugate to reduce antibody affinities for the spacer arm in the immunoassay. The first approach resulted in the preparation of three series of haptens with a spacer attached (1) at the aromatic moiety of pyrethroid, (2) through the middle of the molecule, and (3) at the cyclopropane moiety. Haptens based on the derivatives of the pyrethroid metabolites were also prepared. The second approach involved the use of a linker with a bulky (cyclohexane ring) functionality for preparation of an enzyme conjugate. While most combinations of antibody and conjugate could be used in immunoassays for detection of deltamethrin in the 10-100 μg/L range, in most cases the limits of detection of the assays (for total isomers of a particular target pyrethroid) were lowered 10-50 fold by treatment of the pyrethroid standards with dilute alkali to produce a different isomer mix. Fifteen antisera prepared using 8 haptens were each screened with 14 peroxidase conjugates, and 26 antibody/conjugate combinations were selected for further study on the basis of the assay sensitivity, dynamic behavior, and specificity for deltamethrin, cypermethrin, and cyhalothrin. These immunoassays provided 50% inhibition of antibody binding (IC50) values between 1.5 and 4.2 μg/L of isomerized total deltamethrin and limits of detection of 0.2-0.7 μg/L. The most sensitive immunoassay for total deltamethrin was obtained using cypermethric acid-KLH as the immunogen and a conjugate based on a derivative of cypermethrin coupled through the middle of the molecule to peroxidase. These provided an IC50 of 2 μg/L and a limit of detection of 0.2 μg/L of isomerized total deltamethrin. However, no particular hapten design produced antisera of clearly superior sensitivity or specificity for deltamethrin. Differing cross-reactions with the closely related pyrethroids, deltamethrin, cypermethrin, and cyhalothrin, were obtained, and for several antibodies the cross-reaction as well as the limits of detection could be altered by varying the conjugate combinations. Each of the 12 antibody/enzyme conjugate combinations that sensitively detected deltamethrin were very stereospecific, detecting the αS, 1R cis, (DM1), and αR, 1R cis (DM2) isomers only; the assay sensitivity was greater for the latter isomer.
- Lee, Nanju,McAdam, David P.,Skerritt, John H.
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p. 520 - 534
(2007/10/03)
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- (+)-4-Substituted-2-indanols
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Novel compounds of the formula STR1 are disclosed in which R1 is a phenyl, phenoxy, phenylthio, benzyl or heterocyclic radical which may be substituted, R2 is hydrogen, a substituted-vinylcyclopropanecarbonyl group, a tetramethylcyclopropanecarbonyl group, or a 1-(substituted-phenyl)-2-methylpropylcarbonyl group, and the isomer of S configuration at C-2 of the indanyl ring is present in an enantiomeric excess over the isomer of R configuration. Also disclosed is a method for preparing the optically active alcohols. The compounds wherein R2 is other than hydrogen are insecticides.
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- Process for producing (+)-4-substituted-2-indanols
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Novel compounds of the formula STR1 are disclosed in which R1 is a phenyl, phenoxy, phenylthio, benzyl or heterocyclic radical which may be substituted, R2 is hydrogen, a substituted-vinylcyclopropanecarbonyl group, a tetramethylcyclopropanecarbonyl group, or a 1-(substituted-phenyl)-2-methylpropylcarbonyl group, and the isomer of S configuration at C-2 of the indanyl ring is present in an enantiomeric excess over the isomer of R configuration. Also disclosed is a method for preparing the optically active alcohols. The compounds wherein R2 is other than hydrogen are insecticides.
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- (+)-4-Substituted-2-indanol insecticidal ester derivatives
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Novel compounds of the formula STR1 are disclosed in which R1 is a phenyl, phenoxy, phenylthio, benzyl or heterocyclic radical which may be substituted, R2 is hydrogen, a substituted-vinylcyclopropanecarbonyl group, a tetramethylcyclopropanecarbonyl group, or a 1-(substituted-phenyl)-2-methylpropylcarbonyl group, and the isomer of S configuration at C-2 of the indanyl ring is present in an enantiomeric excess over the isomer of R configuration. Also disclosed is a method for preparing the optically active alcohols. The compounds wherein R2 is other than hydrogen are insecticides.
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- Process for preparation of substituted cyclopropane carboxylic acids and esters thereof and intermediates of said acids and esters
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When 1-halogeno-3-alkene-2-ol is reacted with an ortho-carboxylic ester and/or a ketene acetal, a γ-halogeno-δ-unsaturated-carboxylic ester is obtained as a main reaction product. When this intermediate is treated with a basic substance, a substituted cyclopropane-carboxylic ester is formed. This ester can be used as an insecticide or an agricultural chemical as it is or after the alcohol residue of the ester has been converted to other alcohol residue.
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