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
    Curare-ähnliche „Dimere“ der Indolo[2,3-a]chinolizin-Reihe mit Bicyclo[3.3.1]nonadien-Struktur (1989)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1989 (1989), S. 1029-1035 
    Details
    ISSN: 0170-2041
    Keywords: Aldol cyclization ; Anion complexation ; Bicyclo[3.3.1]nonadienes ; Indolo[2,3-a]quinolizidines, dimerisation of ; NMR effect through space ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Curare-Like “Dimers” of the Indolo[2,3-a]quinolizine Series Containing a Bicyclo[3.3.1]nonadiene Ring System3-Acetyl-7,12-dihydro-2-methyl-6H-indolo[2,3-a]quinoliz
    Notes: 3-Acetyl-7,12-dihydro-2-methyl-6H-indolo[2,3-a]chinoliziniumchlorid (1) reagiert mit Benzaldehyd oder Furfural im Mol-Verhältnis 2:1 unter Piperidin-Katalyse zu den „Dimeren“ 2a, b bzw. 3 mit Bicyclo[3.3.1]nonan-Gerüst. Natriumtetrahydroborat reduziert 2a zum Bicyclo[3.3.1]nonadien 7, Chlorwasserstoff in Essigsäure dehydratisiert 2a zum Mono- und Diolefin 8 bzw. 9. Der am Brücken-Kohlenstoff-Atom befindliche Benzol-(Furan-)Ring mit eingeschränkter Drehbarkeit beeinflußt insbesondere C-9 und bewirkt eine Hochfeldverschiebung der NMR-Signale der dortigen Substituenten. Die Hydroxy-Gruppen von 2a und 3 sind endo-ständig und durch Wasserstoff-Brücken fixiert. Die Stereochemie der Bildungsreaktion von 2a, b wird auf Grund der Röntgenstrukturanalyse von 7 diskutiert.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198919890261
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Synthese des Azocino[4.3-b]indol-Grundgerüstes von Strychnos-Alkaloiden (1993)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1993 (1993), S. 705-710 
    Details
    ISSN: 0170-2041
    Keywords: Azocino[4.3-b]indole, 1,5-methano- ; Carbazoles ; Hexahydrocarbazoles ; Strychnos alkaloids ; Alkaloids ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis of the Azocino[4.3-b]indole Core Structure of Strychnos AlkaloidsMichael addition of ethylmalonic dimethyl or diethyl ester with cyclohexenone and subsequent Fischer indole ring closure afford the (tetrahydrocarbazolyl)malonic esters 4a-c. Decarboxylation of 4a leads to the corresponding butyric acid methyl ester 5 which is oxidized by DDQ to the 4-oxo derivative 6a (byproduct: carbazole 7). Oximation of 6a to 8a and acylation of the oxime group to 8b, c as well as hydrogenation of this group yield 9a, b. Subsequent hydrogenation of the tetrahydrocarbazole ring by means of borane/pyridine yields the hexahydrocarbazole derivatives 10a and b. By cyclisation in boiling o-xylene (sodium hydride catalysis) 10a is converted into the tetracyclic 1,5-methanoazocino[4.3-b]indole derivative 11a with an alkaloid analogous ethyl side chain. The X-ray structural analysis of the corresponding phenylsulfonyl derivative 11b confirms constitution and stereochemistry. As a diastereoisomer of 11a the byproduct 11c could be isolated.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.1993199301115
    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...