- Synthesis and characterization of 3,13- and 2,13-octadecadienyl compounds for identification of the sex pheromone secreted by a clearwing moth, Nokona pernix
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Several geometrical isomers of 3,13- and 2,13-octadecadien-1-ols and their acetates were synthesized starting from 1,8-octanediol or 1,9-nonanediol utilizing acetylene coupling reactions. In addition to commercially available compounds, all geometrical isomers of each dienyl compound were analyzed by NMR and GC-MS to accumulate chemical data for studies of sex pheromones secreted from clearwing moths classified into the family Sesiidae of Lepidoptera. Although acetoxy derivatives of the 3,13- and 2,13-dienes showed almost the same mass spectra, the alcohols were distinguished by comparing the relative intensities of [M - 18]+ at m/z 248, indicating direct differentiation of the two positional isomers without derivatization. Furthermore, each geometrical isomer eluted from a high-polar GC column with a different retention time. Base on these data, a pheromone gland extract of a sesiid moth, Nokona pernix, was analyzed by GC-EAD and GC-MS, and two EAG-active components were identified, viz., the (3E,13Z)- and (3Z,13Z)-isomers of 3,13-octadecadien-1-ol in a ratio of 9:1. In the field, the synthetic compounds mixed in 9:1 ratio attracted N. pernix males well, while a single component scarcely attracted the males. The number of attracted males peaked in the middle of June, and a small second peak was observed in August.
- Naka, Hideshi,Nakazawa, Tomotake,Sugie, Mieko,Yamamoto, Masanobu,Horie, Yoshiteru,Wakasugi, Ryohei,Arita, Yutaka,Sugie, Hajime,Tsuchida, Koji,Ando, Tetsu
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p. 508 - 516
(2008/02/10)
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- A versatile approach to the synthesis of 9(Z)-unsaturated acyclic insect pheromones from undec-10-enoic acid
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A general approach to the synthesis of 9(Z)-unsaturated acyclic insect pheromones from undec-10-enoic acid was developed. The method comprises the conversion of the acid into undec-10-enyl acetate, shortening of its carbon chain to afford dec-9-enyl acetate (via 11-acetoxyundecanoic acid), and a two-step transformation of the latter into the key intermediate, dec-9-yn-1-ol, by sequential bromination - dehydrobromination. The elimination of two HBr molecules from the dibromide is effectively performed using Bu1OK in the presence of dibenzo-18-crown-6 as the catalyst.
- Ishmuratov,Kharisov,Yakovleva,Botsman,Galeeva,Ishmuratova,Tolstikov
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p. 1595 - 1597
(2007/10/03)
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- A facile synthesis of cotton bollworm (Heliothis armigera) pheromone components: (Z)-11-Hexadecenal and (Z)-9-hexadecenal
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(Z)-Hexadecenal (1) and (Z)-9-hexadecenal (2) have been synthesised starting from easily accessible propargyl alcohol.Alkylation of propargyl alcohol yields 3 and 4, which on acetylene-zipper reaction give terminal acetylenes (5 and 6, R'=H).Alkylation of 5 and 6 followed by depyranylation afford 7 and 8.Partial cis-hydrogenation of these with P2Ni followed by PCC oxidation give compounds 1 and 2.
- Mithran, S.,Mamdapur, V. R.
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p. 755 - 756
(2007/10/02)
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- Metamorphosis of Castor Oil to Insect Sex-pheromones and Useful Synthons
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The primary fragmentation products of Castor oil (1), namely, methyl undec-10-enoate (2) and sebacic acid (3) have been converted, using novel reactions and strategies into synthons of the type H-CC-(CH2)n-3-CH2OTHP (n=6=4; n=7=14; n=8=22; n=9=29).A surprisingly clean decarboxylative elimination of sebacic acid monoester gives methyl non-8-enoate (7), a synthon related to recefeiolide and a precursor to 4, the utility of which, has been illustrated with the synthesis of insect-pheromones of the species Grapholita molesta.Methyl dec-9-enoate (15) has been prepared by a novel and practical terminal ? to lower terminal ? degradation of 2.Compound 7 has been transformed via synthon 14 to the insect sex-pheromones of the species, Spodoptera frugiperda, Heliothis virescens and Paralobesia viteana in high yields and excellent stereochemical purity. 1-Tetrahydropyranyloxyundec-10-yne (22) readily prepared from 2, has been used to illustrate a new strategy in pheromone synthesis, namely, the use of coupling elements, leading to the preparation of bombykol in high yields and excellent stereochemical purity. 1-Tetrahydropyranyloxydodec-11-yne (29), already reported, has been transformed to vaccenic acid (30), the transposed ?-isomer of oleic acid, in good yields, thus demonstrating the use of acetylide synthons for the preparation of rare fatty acids also.
- Ranganathan, S.,Maniktala, Vibha,Kumar, Raaj,Singh, G. P.
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p. 1197 - 1207
(2007/10/02)
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- SYNTHESIS OF HIGHER ACETYLENIC ALCOHOLS
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The alkylation of 1-alkynes in various solvents was investigated, and the optimum conditions for the production of acetylenic alcohols were obtained.
- Kovalev, B. G.,Matveeva, E. D.,Stan, V. V.,Vovk, G. A.,Yudin, L. G.,Kost, A. N.
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p. 1728 - 1733
(2007/10/02)
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- INSECT SEX PHEROMONES. STEREOSELECTIVE SYNTHESIS OF SEVERAL (Z)- AND (E)-ALKEN-1-OLS, THEIR ACETATES, AND OF (9Z,12E)-9,12-TETRADECADIEN-1-YL ACETATE
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Several female sex pheromone components produced by moths belonging to the order of Lepidoptera, and potential attractants of Dacus oleae (Diptera:Tripetidae) have been synthesized in high chemical and stereoisomeric purity by improved acetylenic routes involving alkylation of lithium 1-alkyn-1-ides in HMPT, followed by (Z) and (E) highly stereoselective reduction of the derived internal alkynes.Particular care has been paid to optimize the parameters of the reactions used and to evaluate the chemical and isomeric purity of the reaction products.The compounds synthesized include (Z)- and (E)-5-nonen-1-ol, (Z)- and (E)-7-dodecen-1-yl acetate, (Z)- and (E)-7-teradecen-1-yl acetate, (Z)- and (E)-7-nonen-1-ol, (Z)- and (E)-9-tetradecen-1-yl acetate, (Z)- and (E)-10-tetradecen-1-yl acetate, (Z)- and (E)-11-tetradecen-1-yl acetate.Pure (Z)-6-nonen-1-ol, which is an attractant of olive fruit fly, D. oleae, and very probably, a constituent of the sex pheromone of females of this insect, has been prepared by a rather efficient copper-catalyzed reaction between (Z)-3-hexen-1-ylmagnesium bromide and oxetane. (9Z,12E)-9,12-Tetradecadien-1-yl acetate, which is the pheromone of Anagasta kuenniella, Ephestia elutella, Cadra figulella, Spodoptera exigua, S. litura, and a component of the sex pheromones of several other Lepidoptera, has been conveniently prepared by using the copper-catalyzed coupling reaction between (E)-1-chloro-2-butene and 10-tetrahydropyranyloxy-1-decenylmagnesium bromide, followed by acetylation and Z-stereoselective reduction of the derived 1,4-enyne.All syntheses have been conducted on a scale to yield less than 50 mmol of the pure sex pheromone components, but seem adaptable for much larger quantities.
- Rossi, Renzo,Carpita, Adriano,Gaudenzi, Loretta,Quirici, Maria Grazia
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p. 237 - 246
(2007/10/02)
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- (Z)-9-Tetradecen-1-ol formate and its use as a communication disruptant for Heliothis
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(Z)-9-Tetradecen-1-ol formate [(Z)-9-TDF], a chemical of nonbiological origin, was prepared and found to have excellent potential as an insect control agent for the corn earworm, Heliothis zea (Boddie) and tobacco budworm, H. virescens (F.). Mating of H. zea and H. Virescens moths exposed in the field to an atmosphere permeated with (Z)-9-TDF was greatly reduced. The chemical can be used alone to inhibit mating of H. zea or H. virescens or it can be dispensed together with other mating inhibitors to suppress mating in several pest species simultaneously.
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