Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Radical ions and photochemical charge-transfer phenomena. 22. Pressure-induced diastereoselectivity in photoinduced Diels-Alder reactions (1989)
    s.l. : American Chemical Society
    The @journal of organic chemistry 54 (1989), S. 4881-4887 
    Details
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/jo00281a033
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Captodative olefins in normal and inverse Diels-Alder ReactionsPart 3 of Thermal Reactions of Donor-Acceptor Systems. Part 2: [1]. (1988)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 71 (1988), S. 742-748 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Olefins with captodative substitution are reactive dienophiles in Diels-Alder reactions with normal and inverse electron demand. This is shown for reactions of 2-(tert-butylthio)acrylonitrile (1) with various dienes and heterodienes, e.g. 1,3-cyclohexadiene, hexachloro-1, 3-cyclopentadiene, acrolein, methacrolein, and methyl vinyl ketone (Schemes 2 and 3). In case of the hetrodienes, 3,4-dihydro-2H-pyrans are formed beside small amounts of tetrahydrothiophenes; however, with methyl vinyl ketone, both reaction pathways are equally followed. The high reactivity of captodative olefins in Diels-Alder reactions are rationalized on the basis of Sustmann's FMO model under consideration of Viehe's concept of captodative substitution of alkenes.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19880710408
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Asymmetric Induction in the Diels-Alder Reaction of Chiral (2S)-2-(tert-Butyl)-5-methylene-1,3-dioxolan-4-one (1989)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 122 (1989), S. 327-330 
    Details
    ISSN: 0009-2940
    Keywords: Asymmetric induction ; Diels-Alder reaction ; 1,3-Dioxolan-4-one, (2S)-2(tert-butyl)-5-methylene- ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Asymmetrische Induktion in der Diels-Alder-Reaktion von (2S)-2-tert-Butyl-5-methylen-1,3-dioxolan-4-onDie Diels-Alder-Reaktion der Methylenverbindung 3 mit Cyclopentadien bei Raumtemperatur führt zu den Addukten 4 und 5 mit mehr als 95proz. Seitendifferenzierung und 96proz. exo-Selektivität. Die Struktur der Produkte wurde sowohl durch chemische Folgeraktionen als auch durch eine Röntgenstrukturanalyse von 4 bestimmt. Eine Mischung aus 4 und 5 wurde zum optisch aktiven (+)-Norbornenon 12 abgebaut. Katalyse mit TiCl2(PrO)2 sowie AlEtCl2 bei niedrigen Temperaturen verringert dramatisch die Seitendifferenzierung.
    Notes: The Diels-Alder reaction of the cyclic methylene compound 3 with cyclopentadiene at ambient temperature leads to the adducts 4 and 5 with more than 95% face and more than 96% exo selectivity. The structure of the products has been verified by chemical correlation as well as by X-ray diffraction analysis of the Diels-Alder adduct 4. The mixture of 4 and 5 was converted to optically active (+)-norbornenone 12. face Selectivity was dramatically decreased by Lewis acid catalysis with TiCl2(iPrO)2 or AlEtCl2 at lower temperatures.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19891220220
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...