Metastable-ion mass spectra of insect pheromones

The laws of the fragmentation of the metastable molecular and key fragmentary ions of mono- and dienic alcohols, acetates, aldehydes, hydrocarbons, and epoxy compounds forming components of the pheromones of the turnip, tomato, and bollworm moths and other pests of agricultural crops are discussed, and the use of the laws found in the identification of compounds of this class has been demonstrated.     

Analysis of insect pheromones by quadrupole mass fragmentography and high-resolution gas chromatography.

A sensitive technique is described for the analysis of insect pheromones. Insect extracts are separated into fractions by column chromatography and are analyzed directly by quadrupole mass fragmentography on high-resolution glass capillary columns and by mass spectrometry. Applications are illustrated with two important pests. In the codling moth, trans-8, trans-10-dodecadien-1-ol was found to be present at a level of 3.5 ng per female, and in the European grapevine moth trans-7, cis-9-dodecadienyl acetate at a level of 1.6 ng. Both compounds appear to be present in high isomeric purity in the female insect and are absent in the corresponding males.     

Synthesis of dienic fluorinated analogs of insect sex pheromones

Synthesis of fluorinated analogs of some dienic insect sex pherormones through a stereocontrolled Wittig reaction of β-fluorinated aldehydes with the appropriate ω-functionalized ylides is reported. Some features of the ¹H and ¹⁹F NMR spectra of these analogs are also discussed.     

10-Undecenoic acid in the synthesis of insect pheromones

The literature on the use of 10-undecenoic acid in the synthesis of insect pheromones is reviewed.Institute of Organic Chemistry, Ufa Scientific Center, Russian Academy of Sciences, 450054, Ufa, prospekt Oktyabrya 71, fax (3472) 35 60 66. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 87–96, March–April, 2000.     

昆虫性信息素的固相合成

本综述阐明昆虫性信息素固相合成的最新成就。C.C.Leznoff 开创了昆虫性信息素的固相合成,并合成了一系列信息素。他以二醇为原料,以聚合物三苯甲基氯为保护剂。陈德恒等将保护剂改成聚合物三苯甲基氯硅烷,产率比前人有所提高。陈家威等大大改进了前两人的线路,简化了步骤,只抓住关键的一步进行固相合成,总产率比前人提高得更多。     

Use of enyne compounds in the synthesis of insect pheromones

A new approach has been developed to the synthesis of monogenic insect pheromones with acetogenin and macrolide structures, using the low reactivity of ozone and of 9-borabicyclo[3.3.1]nonane towards an acetylenic function as compared with a vinyl function.Institute of Organic Chemistry, Ufa Scientific Center of the Russian Academy of Sciences. Translated from Khimiya Prirodnykh Soedinenii, Vol. 33, No. 1, pp. 34–41, January–February, 1997.     

Simple synthesis of acetogenin transoid insect pheromones starting from acetylcyclopropane

A highly effective synthesis of a series of alkyl and 1-alkenyl cyclopropyl ketones, which are key components in the complete synthesis of a large number of transoid lepidoptera pheromones, has been developed, based on the alkylation of N-cyclohexyl-1-cyclopropylethylideneimine or its condensation with aldehydes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1555–1562, July, 1991.     

A mass-spectrometric study of insect pheromones. II. Epoxy compounds

The mass spectra of epoxy compounds have been studied and the positions of the epoxy rings and their configurations have been shown.V. I. Lenin Tashkent State University. A. S. Sadykov Institute of Bioorganic Chemistry, Uzbekistan Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 130–135, January–February, 1992.     

聚合物支持的三苯基氯硅烷在昆虫性信息素固相合成中的应用

1%二乙烯基苯交联的聚苯乙烯树脂在N,N,N',N'-四甲基乙二胺的存在下用丁基锂进行锂化后与二苯基二氯硅烷反应制得聚苯乙烯支持的三苯基氯硅烷(2).这种聚合物用于一些鳞翅目(lepidoptera)昆虫的性信息素的固相合成.2与1,9-壬二醇,1,10-癸二醇和1,12-十二碳二醇反应分别生成聚合物支持的二醇单硅醚(4a,4b,4c),游离的醇基用Swern试剂(DMSO和草酸酰氯)氧化成聚合物支持的醛(5a,5b,5c),经Wittig缩合反应和用氟离子裂解后分别得到9-十四碳烯醇-1(8a),10-十四碳烯醇-1(8b)和12-十四碳烯醇-1(8c).化合物8经乙酰化后分别得到9-十四碳烯醇-1乙酸酯(9a),其顺式异构体是秋灰夜蛾(S.frugiperda,Smith)的性信息素;10-十四碳烯醇-1乙酸酯(9b),其顺式异构体是橡卷叶蛾(A.semiferamus,Walker)的性信息素;和12-十四碳烯醇-1乙酸酯(9C).9C与四氯化碲反应,硫化钠还原后转化成E-和Z-异构体比例为54:46的亚洲玉米螟(Ostriniafurnicalis)的性信息素.     

General methodology for the synthesis of conjugated dienic insect sex pheromones

A general methodology for the synthesis of various types of dienic insect sex pheromones (Z-E, E-Z, Z-Z) is based on the carbocupration of acetylene by functionalised or non-functionalised lithium dialkyl cuprates, followed by the coupling of the resulting Z dialkenyl cuprates with functionalised or non-functionalised E or Z alkenyl iodides under Pd° catalysis. The following compounds were efficiently synthesized with a high degree of stereoisomeric purity: (E-Z)7, 9-dodecadien,-l-yl acetate 1 (Lobesia botrana), (E-Z)10, 12-hexadecadien,-l-ol 2 (Bombyx mori), (Z-E)9, 11-tetradecadien,-l-yl acetate 3Spodoptera littoralis), (Z-E)5, 7-dodecadien-l-ol 4 (Malascoma disstria), (Z-Z)11, 13-Hexadecadien-l-al 5 (Amyelois transitella), (Z)9,ll-dodecadien-l-yl acetate 6 (Diparopsis castanea) and (Z-Z)9,11-tridecadien-l-yl acetate 22 (a known “pseudo-pheromone”).     

Analyses of lepidopteran sex pheromones by mass spectrometry

Lepidoptera, including about 150,000 species in the world, comprise the second largest insect group, and sex pheromones have been identified from virgin female moths of more than 600 species. The chemical structures are simple, but diverse, because species-specific pheromones play an important role in the reproductive isolation of each species. The pheromone content in each female is quite low, and gas chromatography coupled to mass spectrometry (GC-MS) is most frequently utilized to reveal the chemical structure. Almost all pheromone components are straight-chain compounds and are classified into two major groups [i.e. unsaturated C₁₀-C₁₈ fatty alcohols and their derivatives (Type I) and C₁₇-C₂₃ polyenyl hydrocarbons and their epoxides (Type II)]. In addition to the unbranched compounds, some species secrete methyl-branched compounds (e.g., 2-ketones). For the identification of these compounds, determining the positions of the double bond, the epoxy ring, and the methyl group is an important key step. Copious spectral information measured by electron-impact ionization (70 eV) has been accumulated for these compounds. This review therefore deals with their spectral characteristics, namely, diagnostic ions, to apply them to pheromone studies on new target insects.     

Ti-catalyzed cross-cyclomagnesiation of 1,2-dienes in the stereoselective synthesis of insect pheromones

The Ti-catalyzed intermolecular cross-cyclomagnesiation reaction of aliphatic and oxygenated 1,2-dienes with Grignard reagents was used as the key step to develop facile stereoselective methods for preparation of the major components of citrus leafminer moth (Phyllocnistis citrella) pheromones as well as cotton pink bollworm (Pectinophora gossypiella) and fruit fly (Drosophila melanogaster) attractants.     

New stereocontrolled approach to some insect pheromones via silicon-directed beckmann fragmentation

The major components of sex pheromones of potato tuberworm moth and Douglas fir tussock moth have been synthesized via the regio- and stereo-controlled Beckmann fragmentation assisted by trimethylsilyl group.     

Synthesis of monoenic aliphatic pheromones of insect pests of the cotton plant

Advances in the last decade in the field of the synthesis of monoenic aliphatic pheromones of insect pests of the cotton plant are generalized.For the seventieth birthday of Academician A. S. Sadykov.A. S. Sadykov Institute of Bioorganic Chemistry, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 633–647, September–October, 1988.     

Synthesis of insect trail pheromones: The isomeric 3-butyl-5-methyloctahydroindolizines

The syntheses of the geometrical isomers of 3-butyl-5-methyloctahydroindolizine are described. These compounds, reported as trail pheromones of Pharaoh ants, Monomorium pharaonis (L.), cannot be distinguished from each other by physical data alone and assignments must therefore be based on unambiguous synthesis. Routes to these compounds via suitably constituted dialkylpiperidines and a sequence involving a dialkylpyrrole are described. Infrared and nmr spectral data are presented. These data are examined for their potential in conformaational analyses of these compounds.     

Bioluminescent detection of insect pheromones using an enzyme-based flow injection analysis system

The combination of flow injection analysis with chemiluminescent detection is shown to provide extremely selective and sensitive detection of insect pheromones which possess an aldehyde moiety. The flow injection analysis system provides reproducible control of both the reaction chemistry and the sample introduction process. Microliter volume samples can be precisely handled and analyzed with this experimental configuration. The detection system is based on the luciferase-catalyzed oxidation of reduced flavin mononucleotide which occurs in the presence of aldehydes with carbon backbones of between 14 and 16 carbons. A limit of detection of 3 fmol of tetradecyl aldehyde is demonstrated and the system is shown to be insensitive to the presence of various organic solvents up to concentrations of approximately 10%. The key experimental variables which control sensitive detection of pheromone at the femtomole level with be investigated and discussed.     

Interpretation of mass spectra

A computer programme is described which calculates the mass numbers and the relative intensities of each of the lines in the cluster formed in a mass spectrometer from a single type of fragment ion which contains one or more polyisotopic elements. Many elements such as B, C, S, Cl and Br possess more than one naturally occurring isotope, and the relative abundances of the various isotopes are known. A whole series of possible fragment ions may be calculated quite readily, and the results, which are printed numerically and in the form of a histogram, facilitate the interpretation of mass spectra. Trial data, a FORTRAN listing of the programme, and a sample of the output are given. The programme requires approximately 17K of fast core, and should be implemented without difficulty on any computer with a FORTRAN IV compiler.     

昆虫信息素研究III: 拟蚜虫警戒素的研究

合成了一系列碳数为十五和十四的倍半萜类蚜虫警戒素,并进行了生物活性测定,从中筛选有效化合物.     

Computer-aided interpretation of mass spectra

A system is described in which computer techniques are used to carry out major steps in the procedure for interpretation of high-resolution mass spectral data. These steps include identification and evaluation of the molecular ion, neutral fragments lost from the molecular ion, and characteristic ion series, followed by elucidation of specific structural details using a sub-routine for the particular compound class selected. The technique shows promise of not only increasing the interpreter's efficiency, but of providing more specific and detailed structural information from the spectral data.