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  • 1
    ISSN: 1573-1561
    Keywords: Matsucoccus josephi ; Elatophilus hebraicus ; Homoptera ; Heteroptera ; Matsucoccidae ; Anthocoridae ; scale insect ; pine bast scale ; predator ; Pinus halepensis ; Pinus brutia ; sex pheromone (2E,6E,8E)-5,7-dimethyl-2,6,8-decatrien-4-one ; trap color ; trap position
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The active component of the sex pheromone ofMatsucoccus josephi is (2E,6E,8E)-5,7-dimethyl-2,6,8-decatrien-4-one; the chemical is also a powerful kairomone of adult males and females of the bugElatophilus hebraicus the principal predator ofM. josephi. The presence of theZ isomer (2E,6Z,8E)-5,7-dimethyl-2,6,8-decatrien-4-one does not interfere with the attractancy of the activeE component forM. josephi males or the bug. Our results show a clear dose-response between trap catch ofM. josephi males andE. hebraicus. Conversely, increasing amounts of theZ isomer in the mixture did not affect the attraction of the scale insect males or the bug. The catch ofM. josephi males did not differ significantly among traps of different color, and was significantly higher with traps attached to the tree trunk than those suspended between trees. Comparison of the catch ofM. josephi among the three forests and between pine species suggests that the level of infestation ofPinus halepepsis andPinus brutia ssp.brutia is similar, despite the fact that the latter pine is resistant to the scale insect. Both sexes ofE. hebraicus were trapped in much lower numbers at the more infested sites. This may be related to interference with the activity ofE. hebraicus due to deterioration and drying of parts of the tree crowns and heavy colonization by generalist predators in injured trees.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 19 (1998), S. 1786-1794 
    ISSN: 0192-8651
    Keywords: gear effect ; internal rotation ; molecular mechanics ; MM3 force field ; hindered systems ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: MM3-based calculations showed that bicycles and polycycles with four- to six-membered rings-components of the bi- and polycyclic backbone are sufficiently rigid to keep a syn-periplanar orientation of vicinal tert-butyl substituents. As a result of the spatial proximity of these groups, their rotation occurs in a concerted manner as demonstrated by conformational schemes that are built using MM3-derived methodology. Only correlated disrotation in saturated systems with four- to five-membered rings-components and in the adamantane system leads to isochronism for Me groups of the tert-Bu substituents (i.e., to dynamic gearing in Mislow's terms). Moreover, correlated rotation of these substituents is coupled with a change of the backbone geometry (pseudorotation) except in the most rigid bicyclo[2.1.1]hexa-2-ene system. Thus, a new type of dynamic gearing, correlated rotation-rotation-pseudorotation, is predicted for quasirigid bi- and polycycles with syn-periplanar oriented tert-Bu substituents.   © 1998 John Wiley & Sons, Inc.   J Comput Chem 19: 1786-1794, 1998
    Additional Material: 5 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 26 (1991), S. 667-668 
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 2000 (2000), S. 645-655 
    ISSN: 1434-193X
    Keywords: INOC ; Pyrrolidines ; Piperidines ; Stereoselective synthesis ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Intramolecular nitrile oxide olefin cycloaddition (INOC) reactions of oximes 1-3 and of 24-27 derived from L-amino acids have been found to proceed stereoselectively, yielding tricyclic fused pyrrolidines and piperidines. Further manipulation led to chiral hydroxymethyl-substituted fused piperidines 33-35 and to 3-amino-4-(1-hydroxypropyl)-2-mercaptomethyl-N-methylpiperidine (36). The structures and stereochemistries of the fused systems, as well as those of the piperidines, have been established by NMR.
    Additional Material: 3 Ill.
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  • 5
    ISSN: 0947-3440
    Keywords: Dipolar cycloadditions ; Tandem Michael additions ; Silyl nitronates ; Tetrahydrofurans ; Isoxazolidines ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The intramolecular silyl nitronate olefin cycloaddition (ISOC) leading to substituted, fused-ring tetrahydrofurans 6 was examined with regard to optimum conditions and substituent effects. The required unsaturated nitro ethers 3 resulted from low-temperature, base-mediated Michael addition of allyl alcohols 2 to nitroolefins 1, followed by conversion to unsaturated silyl nitronates 4. Cycloaddition of the latter and elimination of silanol provided 6. One-pot tandem reactions, starting with nitroolefins 1 and allyl alcohols 2 and involving four steps, sometimes proceeded in better yields but often gave unexpected side products. Terminal olefinic electron-donating substituents (Me, MeO) increased the rate of cycloaddition, while an internal olefinic methyl substituent slowed down the reaction. In the case of nitronates possessing ester or nitrile moieties as terminal olefin substituents, tandem Michael addition to produce substituted furans 14, 15 occurred faster than trapping of the nitronate anion by TMSCI.
    Additional Material: 1 Tab.
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 121 (1988), S. 1823-1826 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Alkylierung und Aldol-Reaktionen von Aldoxim-AnionenZ-Aldoxime liefern mit BuLi Dianionen, deren Eigenschaften untersucht wurden. Isotopenmarkierung (mit D) und Silylierung bestätigen frühere Befunde, daß nur das Z-Isomer Anionen bildet. Z-Hexanal- und Z-Octanal-oxim wurden mit BuLi deprotoniert. Deren Anionen reagieren in Aldol-Kondensations-Reaktionen mit verschiedenen Aldehyden und Ketonen einschließlich α,β-ungesättigten Aldehyden. Versuche, die Monoanionen von O-Tetrahydropyranyl-Ethern von Aldoximen zu alkylieren, schlugen fehl. Dagegen wurde bei einigen O-Tetrahydropyranyl-Ethern von Oximen eine Addition des Carbanions an die C=N-Bindung beobachtet.
    Notes: The reaction of Z aldoximes with BuLi to give dianions and the properties of the latter were examined. D-Labelling and silylation confirm previous findings that only the Z isomer forms the dianion. Z-Hexanal oxime and Z-octanal oxime were deprotonated with BuLi, and the anions underwent aldol condensation reactions with several aldehydes and ketones including α,β-unsaturated aldehydes. Attempts to alkylate monoanions of OTHP ethers of aldoximes failed. However, carbanion addition to the C=N bond of some oxime OTHP ethers was observed.
    Additional Material: 2 Tab.
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 124 (1991), S. 1181-1186 
    ISSN: 0009-2940
    Keywords: Stereoselective cyclizations ; Ethers, cyclic ; Dipolar cycloaddition ; Nitro olefins ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A convenient conversion of aldehydes via nitroolefins 2 into cyclic ethers 6 fused to an isoxazoline ring involves formation of unsaturated nitroalkyl ethers 4 and subsequent intramolecular cycloaddition of an in situ-formed nitrile oxide olefin. The cyclization proceeds with stereoselective formation of trans over cis isomers in the tetrahydrofuran series and opposite stereoselectivity in the tetrahydropyran and hexahydrooxepine series, depending on the substituent R in the original nitro compound, thus providing access to stereoselectively functionalized cyclic ethers.
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 493-498 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Studies on UV/Vis Absorption Spectra of Azo Dyes. XVIII. Substituent Effects on the Absorption Maxima of the n → π* and π → π* Bands of 4-N,N-DiethylaminoazobenzenesThe spectra of 27 substituted 4-N.N-diethylaminoazobenzenes are determined. The band systems can be separated by deconvolution into two Gaussian curves. The results so obtained show that the effects of substituents on n → π* and π → π* transitions are similar and that electron withdrawing substituents in the phenylazo residue cause a bathochromic shift of both the n → π* and the π → π* bands.
    Additional Material: 3 Tab.
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 80 (1968), S. 631-631 
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 98 (1986), S. 479-480 
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Tab.
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