- CYCLOADDITIONS OF HEXACHLOROCYCLOPENTADIENE TO 7-SUBSTITUTED NORBORNADIENES: REMOTE SUBSTITUENT EFFECTS ON REACTIVITY AND STEREOSELECTIVITY
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The rates and stereoselectivities of the cycloadditions of hexachlorocyclopentadiene to norbornadienes substituted at the 7-position by tert-butyl, trimethylsilyl, methoxy, acetoxy, hydroxy, methoxymethyl, and methoxycarbonyl groups have been measured.The rates correlate with substituent electronegativities.
- Houk, K. N.,Mueller, Paul H.,Wu, Yun-Dong,Mazzocchi, Paul H.,Shook, David,Khachik, Frederick
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- NOXIOUS ARTHROPOD CONTROL AGENT CONTAINING AMIDE COMPOUND
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An object of the present invention is to provide a compound having the controlling activity on a noxious arthropod, and a noxious arthropod controlling agent containing an amide compound of formula (I): wherein X represents a nitrogen atom or a CH group, p represents 0 or 1, A represents a tetrahydrofuranyl group or the like, R1, R2, R3, R4, R5, R6 and R7 represent a hydrogen atom or the like, n represents 1 or 2, Y represents an oxygen atom or the like, m represents any integer of 0 to 7, and Q represents a C1-8 chain hydrocarbon group optionally having a phenyl group or the like, has the excellent noxious arthropod controlling effect.
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- Physical, chemical, and isotopic (atomic) labels
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Chemical or isotopic labels are added to, e.g., a potentially lethal drug formulation, to generate a unique chemical fingerprint. Combinations of chemical additives are mixed with the drug to aid in their isolation and identification, especially when such drugs are used for illicit purposes. When stable isotopes are incorporated into lethal drugs, the labeling process conveys a very unique internal chemical signature and greatly aids in the identification of the parent drug in body fluids and tissues. When heath-care providers become aware that certain drugs can now be easily tracked and identified in a victim, individuals may be reluctant to utilize these agents for ill purposes.
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- Transannular orbital interaction between ketone and olefin chromophores detected by circular dichroism and13C-NMR spectroscopy. Dimethanonaphthalenones and trimethanoanthracenones
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A series of δ,ε-unsaturated ketones and their saturated ketone analogs were synthesized on the dimethanonaphthalene skeleton with endo-endo (1), endo-exo (2), and exo-exo (3) configurations. The corresponding norbornylogs (trimethanoanthracenes) with ζ,η-unsaturated ketones (4, 5, and 6) and their saturated analogs were also synthesized. Their 13C-NMR and circular dichroism (CD) spectra were measured in order to examine transannular orbital interactions. Transannular orbital interaction was detected by a relatively more shielded 13C=O resonance in the unsaturated ketones. The shielding was largest when the C=O and C=C chromophores could interact through ρ-pp orbital overlap, as in 1. That is, orbital interaction through space is an important component of the ground state of 1. In the CD spectra, the ketone n-π* Δεmax values were typically larger for the unsaturated ketones, as compared with their saturated ketone analogs. The n-π* Δεmax enhancements fall off with increasing interchromophoric distance, as seen in the trimethanoanthracenes. The presence of "charge-transfer" CD bands near 230 nm in the unsaturated ketones suggests a component of "through-space" orbital interaction. The intensity of the CD charge-transfer bands is greatest when the chromophores are oriented for ρ-pp orbital interaction. Orbital interaction through space appears to be an important component of the excited state of 1 and 2, and even 4, but it appears to play a less important role in 3, 5, and 6.
- Robbins, Timothy A.,Van Toan, Vien,Givens III, John W.,Lightner, David A.
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p. 10799 - 10810
(2007/10/02)
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