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  • 1
    Electronic Resource
    Electronic Resource
    Influence of the β-substitution on the photochemistry of α,2-diacetoxystyrenes. Irradiation of phenyl, vinyl, and benzyl derivatives (1990)
    Springer
    Monatshefte für Chemie 121 (1990), S. 267-274 
    Details
    ISSN: 1434-4475
    Keywords: Photolysis ; α-Acetoxystyrenes ; Neighbouring group participation ; Chromones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Bei α,2-Diacetoxystyrolen haben die β-Substituenten einen deutlichen Einfluß auf das photochemische Verhalten. Wie im Fall der Stammverbindung erfolgt bei der Bestrahlung der Enolester4a–c intramoleukulare Cyclisierung unter Einbeziehung der benachbarten 2-Acetoxygruppe; jedoch werden je nach Substrat auch andere Reaktionen beobachtet. Das Phenylderivat4a liefert dasE-Isomer7a und das Phenanthren9. Das Vinylderivat4b erfährt ebenfallscis/trans-Isomerisierung zu7b und/oder Photooxidation zu10. Beim Benzylderivat4c tritt eine 1,4-Acylverschiebung zum 1,4-Diketon12 auf.
    Notes: Summary β-Substitution shows a pronounced influence on the photochemistry of α,2-diacetoxystyrenes. As in the case of the parent compound, intramolecular cyclization with participation of the neighbouring 2-acetoxy group takes place upon irradiation of the enol esters4a–c; however other processes are also observed, depending on the substrate. The phenyl derivative4a gives theE isomer7a and the phenanthrene9. The vinyl derivative4b also undergoescis-trans isomerization and/or photooxidation, to afford7b and10. Finally, a 1,4-acyl migration occurs in the benzyl derivative4c, whereby the 1,4-diketone12 is formed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00808927
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  • 2
    Electronic Resource
    Electronic Resource
    Electron transfer photofragmentations of 3-phenylpropiophenones (1990)
    Springer
    Monatshefte für Chemie 121 (1990), S. 371-375 
    Details
    ISSN: 1434-4475
    Keywords: Photosensibilization ; Electron transfer ; 2,4,6-Triphenylpyrylium tetrafluoroborate ; 3-Phenylpropiophenones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Photolyse der 3-Phenylpropiophenone1 a–d in Gegenwart von 2,4,6-Triphenyl-pyrylium-tetrafluoroborat (TPT) ergeben die entsprechenden α,β-ungesättigten Ketone2 a–c und1 d (aus1 c), neben Acetophenon (3), Benzophenon (4), Benzoesäure (5) und Benzaldehyd (6), vermutlich durch Fragmentierung des Radikal-Kations1 + ·, das mittels Übertragung eines Elektrons von1 zuTPT im angeregten Zustand erzeugt wird.
    Notes: Summary Photolysis of 3-phenylpropiophenones1 a–d in the presence of 2,4,6-triphenylpyrylium tetrafluoroborate (TPT) yields the corresponding α,β-unsaturated ketones2 a–c and1 d (from1 c), together with acetophenone (3), benzophenone (4), benzoic acid (5) and benzaldehyde (6), presumably by fragmentations of the radical cation1 + ·, generated via a single electron transfer process from1 to the excitedTPT.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00809453
    Library Location Call Number Volume/Issue/Year Availability
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    Paper (German National Licenses)
    Fulltext
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