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  • 1
    Electronic Resource
    Electronic Resource
    Hydroacridines XVIII [1]. Synthesis and NMR Spectroscopic Investigation of(4aα,8aβ,9aα,10aβ)-Tetradecahydroacridine and Some of its Derivatives (1998)
    Springer
    Monatshefte für Chemie 129 (1998), S. 515-522 
    Details
    ISSN: 1434-4475
    Keywords: Keywords. Acridines ; tetradecahydro; 13C NMR; Conformational analysis; N-Nitrosamines.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung.  Die reduktive Aminierung von (R *,R *)-2,2′-Methylen-bis-cyclohexanon (1) mit Methylamin und Kaliumborhydrid ergibt in einer Gesamtausbeute von 57% ein Gemisch aus (4aα,8aβ,9aα,10aβ)- und (4aα,8aα,9aβ,10aα)-Tetradecahydro-10-methylacridin (2, 3) im Verhältnis von ca. 1.3:1. Durch N-Demethylierung von 2 gelang über das Nitrosamin 4 die erste Synthese von (4aα,8aβ,9aα,10aβ)-Tetradecahydroacridin (5). Die relativen Konfigurationen und die Konformationen der Verbindungen 2–5 sowie die Aktivierungsenergie der Konformationsumwandlung von 5 (ΔG 300 #=55.5±0.4 kJċmol−1) wurden NMR-spektroskopisch bestimmt.
    Notes: Summary.  The reductive amination of (R *,R *)-2,2′-methylene-bis-cyclohexanone (1) with methylamine and potassium borohydride affords a mixture of (4aα,8aβ,9aα,10aβ)- and (4aα,8aα,9aβ,10aα)-tetradecahydro-10-methylacridine (2, 3) in a ratio of approximately 1.3:1 in 57% overall yield. By N-demethylation of 2, via the N-nitrosamine 4 the first synthesis of (4aα,8aβ,9aα,10aβ)-tetradecahydroacridine (5) could be performed. The relative configurations and conformations of compounds 2–5 as well as the barrier of conformational inversion of 5 (ΔG 300 #=55.5±0.4 kJċmol−-1) were determined by NMR spectroscopy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00000108
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  • 2
    Electronic Resource
    Electronic Resource
    Hydroacridines XIX [1]. 13C NMR Spectra of Several N-Alkyl-tetradecahydroacridines and their Protonated Species: Investigation of the N-Epimeric Equilibria of the N-Alkyl Groups in the Amines and in the Salts (1999)
    Springer
    Monatshefte für Chemie 130 (1999), S. 537-544 
    Details
    ISSN: 1434-4475
    Keywords: Keywords. Acridines ; tetradecahydro; N-Epimeric equilibria; 13C NMR.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung.  (4aα,8aβ,9aβ,10aα)-Tetradecahydro-10-methylacridin, (4aα,8aβ,9aβ,10aα)-10-Ethyl-tetradecahydroacridin, (4aα,8aα,9aβ,10aα)-Tetradecahydro-10-methylacridin, (4aα,8aα, 9aβ,10aα)-10-Ethyl-tetradecahydroacridin und deren Protonierungsprodukte mit Trifluoressigsäure wurden 13C-NMR-spektroskopisch untersucht. Die beiden erstgenannten Amine ergeben jeweils ein Paar N-diastereomerer Salze, während aus den beiden letzteren nur die Salze mit äquatorialen N-Alkylgruppen entstehen. Die N-epimeren Gleichgewichte der N-Alkylgruppen (äquatorial-axial) in den Salzen und in den Aminen werden diskutiert.
    Notes: Summary.  (4aα,8aβ,9aβ,10aα)-Tetradecahydro-10-methylacridin, (4aα,8aβ,9aβ,10aα)-10-ethyl-tetradecahydroacridin, (4aα,8aα,9aβ,10aα)-tetradecahydro-10-methylacridine, (4aα,8aα,9aβ,10aα)-10-ethyl-tetradecahydroacridin and their products of protonation with trifluoroacetic acid were studied by 13C NMR spectroscopy. The first two amines give rise to a pair of N-diastereomeric salts, whereas the latter two yield only the salts with equatorial N-alkyl groups. The N-epimeric equilibria of the N-alkyl groups (equatorial-axial) in the salts and in the amines are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00010232
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  • 3
    Electronic Resource
    Electronic Resource
    Hydroacridines XX [1]. Stereochemical Factors Influencing the 13C NMR Protonation Shiftsof Six-membered Saturated Azaheterocyclic Tertiary Amines (1999)
    Springer
    Monatshefte für Chemie 130 (1999), S. 691-702 
    Details
    ISSN: 1434-4475
    Keywords: Keywords. Acridines ; tetradecahydro; Quinolines ; decahydro; 13C NMR; Protonation shifts; Solvent effects.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung.  Der Einfluß stereochemischer Faktoren auf die durch N-Protonierung von sechsgliedrigen gesättigten azaheterozyklischen tertiären Aminen hervorgerufenen 13C-NMR-Verschiebungen wurde anhand von (4aα,8aβ,9aβ,10aα)-Tetradecahydro-10-methylacridin, (4aα,8aβ,9aβ,10aα)-10-Ethyl-tetradecahydroacridin, (4aα,8aα,9aβ,10aα)-Tetradecahydro-10-methylacridin und (4aα,8aα,9aβ,10aα)-10-Ethyl-tetradecahydroacridin als Modellverbindungen untersucht. Die Größe der 13C-Protonierungsshifts ist von folgenden stereochemischen Faktoren abhängig: (i) der Protonierung über ein axiales oder ein äquatoriales unbeteiligtes Elektronenpaar des Stickstoffatoms, (ii) des relativen sterischen Verhältnisses (γ-gauche oder γ-anti) zwischen dem Stickstoffatom und den in γ-Stellung befindlichen Kohlenstoffatomen und (iii) der Geometrie des gesamten Kohlenstoffgerüsts. Gleiche stereochemische Abhängigkeiten werden für die Protonierungsverschiebungen von N-Methyl-trans-decahydroquinolin gefunden, die auf der Basis von Literaturdaten untersucht wurden. Die beobachteten Protonierungsverschiebungen können mittels der Theorie der linearen elektrischen Feldverschiebung (LEFS) gut erklärt werden.
    Notes: Summary.  The influence of stereochemical factors upon 13C NMR shifts induced by N-protonation of saturated azaheterocyclic tertiary amines was investigated using (4aα,8aβ,9aβ,10aα)-tetradecahydro-10-methylacridine, (4aα,8aβ,9aβ,10aα)-10-ethyl-tetradecahydroacridine, (4aα,8aα, 9aβ,10aα)-tetradecahydro-10-methylacridine, and (4aα,8aα,9aβ,10aα)-10-ethyl-tetradecahydroacridine as model compounds. The magnitudes of the protonation shifts depend on the following stereochemical factors: (i) whether protonation occurs through an axial or an equatorial nitrogen electron lone-pair, (ii) the relative steric orientation (γ-gauche or γ-anti) of the nitrogen and carbon atoms in γ position, and (iii) the geometry of the entire carbon skeleton. Similar stereochemical dependences were found for the protonation shifts on N-methyl-trans-decahydroquinoline, analyzed on the basis of chemical shift data from literature. The observed protonation shifts can be well rationalized in terms of the LEFS (linear electric field shift) theory.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00010250
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  • 4
    Electronic Resource
    Electronic Resource
    Hydroacridines XXI [1]. 13C NMR Spectroscopic Investigation of the Stereoselectivities of Quaternizations of N-Alkyl Derivatives of (4aα,8aβ,9aβ,10aα)- and (4aα,8aα,9aβ,10aα)-Tetradecahydroacridine (2000)
    Springer
    Monatshefte für Chemie 131 (2000), S. 345-352 
    Details
    ISSN: 1434-4475
    Keywords: Keywords. Acridines, tetradecahydro; 13C NMR; 13C-Labelling; Stereoselective reactions.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary.  The stereoselectivities of the quaternization reactions of (4aα,8aβ,9aβ,10aα)- and (4aα,8aα,9aβ,10aα)-tetradecahydro-10-methylacridine with methyl- and ethyl iodide as well as those of (4aα,8aβ,9aβ,10aα)- and (4aα,8aα,9aβ,10aα)-10-ethyl-tetradecahydroacridine with methyl iodide were investigated using 13C NMR spectroscopy including 13C-labelling where appropriate. The methylations of both N-methyl amines occur by predominant (60% and 75%, respectively) equatorial approach, their ethylations occur sterospecifically by equatorial approach, and the methylations of the N-ethyl amines occur by highly stereoselective (〉 90%) axial approach of the quaternizing reagent.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00010310
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  • 5
    Electronic Resource
    Electronic Resource
    Hydroacridine, XIII. Sterischer Verlauf der N-Oxidation von N-Alkyl-Derivaten des (4aα,8aβ,9aβ,10aα)-Tetradecahydroacridins (α-Perhydroacridin)Diese Arbeit wurde auf der 5. rumänischen Konferenz für allgemeine und angewandte physikalische Chemie, Bukarest, 1. -4. September 1976, mitgeteilt. (1990)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1990 (1990), S. 99-100 
    Details
    ISSN: 0170-2041
    Keywords: Amine oxides ; Acridines N-alkylperhydro- ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Hydroacridines, XIII.  -  Steric Course of the N-Oxidation of N-Alkyl Derivatives of ((4aα,8aβ,9aβ,10aα)-Tetradecahydroacridine (α-Perhydroacridine)Diese Arbeit wurde auf der 5. rumänischen Konferenz für allgemeine und angewandte physikalische Chemie, Bukarest, 1. -4. September 1976, mitgeteilt.The oxidation of N-methyl-α-perhydroacridine (1), with hydrogen peroxide at room temperature occurs approximately with 83% by equatorial, and approximately with 17% by axial attack of the oxygen on the nitrogen atom. The oxidations of N-ethyl- (2) and N-benzyl-α-perhydroacridine (3) yield only the N-oxides with axial oxygen (2′a and 3′a, respectively).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.199019900114
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  • 6
    Electronic Resource
    Electronic Resource
    Hydroacridines. XIVFor Part XIII, see Ref. 1. - carbon-13 NMR spectra of three perhydroacridine stereoisomers (1994)
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 32 (1994), S. 563-564 
    Details
    ISSN: 0749-1581
    Keywords: 13C NMR ; Tetradecahydroacridines ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The 13C NMR chemical shifts of (4aα,8aα, 9aβ, 10aα)-, (4aα,8aα,9aα, 10aβ)- and (4aα,8aβ,9aα, 10aβ)-tetradecahydroacridine were measured and fully assigned on the basis of APT, 13C, 1H shift correlation and 2D-INADEQUATE spectra.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/mrc.1260320916
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