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  • 1
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Studies on Sulphochlorination of Paraffins. V. Kinetic Studies on the Sulphochlorination of Pure AlkanesulphochloridesThe mixtures of disulphochlorides formed by sulphochlorination of 1-alkanesulphochlorides C4—C9 may be analyzed gaschromatographically after transformation into the corresponding dimethylamides. The individual peaks could be identified in some cases with the aid of pure isomeric disulphochlorides, in other cases they were identified by analogy. The mixtures formed by sulphochlorination of the isomeric heptane sulphochlorides also could be analyzed after transformation into the dimethylamides; the identification of all peaks was possible by comparison of the mixtures obtained from different heptane sulphochlorides.For the alkane sulphochlorides studied the relative rates of sulphochlorination (with reference to n-octane) were determined, and therefore the relative reaction rates of the individual C—H-bonds with reference to one primary C—H-bond of n-octane could be calculated.The results show a geminal or vicinal disubstitution not to take place in noticeable amount. In position 3 or in greater distance the influence of the sulphochloride group on the reactivity of the C—H-bonds is not significant.
    Additional Material: 7 Tab.
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  • 2
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Steroids. LIII. 1H N.M.R.-Investigations. Configurational Assignment of 16-Substituted 17-Hydroxy SteroidsThe 1H n.m.r. spectra of epimeric 16-substituted 17β-hydroxy-3-methoxy-estra-1,3,5(10)-trienes can be used for configurational assignment. The values of the coupling constants J16,17 allow the elucidation of the configuration, when all of the four epimeric compounds with the same 16-substituent are available. When only one compound is available, a reliable configurational assignment by J16,17 is only possible, when J ≤ 2 cps (16β,17α-configuration of the substituents) or when J 〉 8 cps (16β,17β-configuration). Further parameters for configurational assignment are the chemical shifts of the 13β-methyl protons and the 17-proton, the downfield shifts of the 17-proton signals, caused by acetylation or by “in situ” reaction with trichloroacetyl isocyanate, and the chemical shift as well as the sum of the coupling constants of the 16-protons. The contributions of the 16-substituents to the chemical shift of the 17-proton are compared with similar values, obtained from 1-substituted acenaphthenes. Equations for the calculation of these contributions are presented for the trans compounds.
    Notes: Die 1H-NMR-Spektren epimerer 16-substituierter 17-Hydroxy-3-methoxyöstra-1,3,5(10)-triene werden zur Konfigurationsbestimmung herangezogen. Aus der Kopplungskonstante J16,17 kann die Konfiguration eindeutig ermittelt werden, wenn die vier möglichen Epimeren mit gleichem 16-Substituenten vorliegen. Liegt nur eine Verbindung vor, ist eine sichere Zuordnung allein durch J16,17 nur möglich, wenn J ≤ 2 Hz ist (16β,17α-Konfiguration der Substituenten) oder wenn J 〉 8 Hz ist (16β,17β-Konfiguration). Weitere zur Konfigurationsbestimmung geeignete Parameter sind die chemische Verschiebung der 13β-Methylprotonen und die des 17-Protons, die Tieffeldverschiebung dieses Signals nach Acetylierung oder nach „in situ“-Reaktion mit Trichloracetylisocyanat sowie chemische Verschiebung und Gesamtaufspaltung des 16-Protonensignals. Die Beiträge der 16-Substituenten zur chemischen Verschiebung des 17-Protons werden mit den aus 1-substituierten Acenaphthenen erhaltenen Werten verglichen. Gleichungen zur Berechnung dieser Beiträge für die trans-Verbindungen werden angegeben.
    Additional Material: 8 Tab.
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 318 (1976), S. 515-518 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Tab.
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  • 4
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1H and 13C n.m.r. Spectroscopical Measurements and HMO-π-Calculations to the π-Electronic Structure of p,p′-Disubstituted trans-Stilbenes and Substituted trans-β-Styryl-methyl-SulfonesThe 1H and 13C n.m.r. spectra have been measured for a series of donator-acceptor-disubstituted trans-stilbenes 1 and monosubstituted β-styryl-methyl-sulfones 2. The 13C n.m.r.-signals have been identified by comparison with empirical calculated chemical shifts and quantum chemical determined HMO-π-electrons densities. The influence of substitutents to the experimental chemical shifts are discussed in detail. For 1 and 2 exist linear correlations between chemical shifts and HAMMETT values, and π-electron densities, respectively.
    Additional Material: 1 Ill.
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  • 5
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Configuration of Diastereomeric 9-Methylcarbazole CompoundsA synthetic route including Reformatsky and Curtius reactions has been used for the preparation of the diastereomeric ß-hydroxyesters 1a, b, hydroxyhydrazides 4a, b, oxazolidones 6a, b and 8c-e, amino alcohols 7a -e and some related compounds in good yields. The relative configurations of 1a, b have been determined by a thin-layer chromatographic method. The configuration and conformation of the diastereomeric carbazole derivatives have been studied by1H-NMR and IR spectroscopy.
    Notes: Es wurden Reformatsky- und Curtius-Reaktionen von Carbazol-Derivaten untersucht, wobei mit guten Ausbeuten diastereomere ß-Hydroxydrazide, 4a b, Oxyzolidone 6a b und 8c-e,ß -Aminoalkohole 7a-e wie auch einige verwandte Verbindungen erhalten wurden. Die Konfigurationen von 1a, b wurden mit einer dünnschichtchromatographischen Methode be-stimmt. Konfiguration und Konformation der Diastereomeren wurden .1H-NMR- und IR-spektroskopisch ermittelt.
    Additional Material: 4 Tab.
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1979 (1979), S. 533-546 
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of Substituted Bicyclo[4.3.1]decatrienyl CationsThe rearrangement of bicyclo[4.2.2]decatetraenes to bicyclo[4.3.1]decatrienes on addition of electrophiles opens a route to methano-bridged dihomotropylium ions. We report here on some substituted cations, namely 2-methyl- (16), 2-chloro- (22), 2-bromo- (26), 2,5-dimethyl- (29), 1-methyl- (37), 1-chloro- (38), 1-bromo- (39), 7-phenyl- (42) and the 7-(2-methoxyphenyl)bicyclo]4.3.1]decatrienylcation (44). Cyclic π-electron delocalization in the bicyclo[4.3.1]-decatrienyl cation (1) is more or less disturbed but never suppressed by the substituents mentioned.-3-Methylbicyclo[4.2.2]decatetraene (30) behaves atypically on addition of HBr. 10-exo-Methoxy-4-methyltricyclo[4.3.1.02,9]deca-3,7-diene (33) is isolated after solvolysis with methanol. A mechanistic interpretation is given.
    Notes: Bicyclo[4.2.2]decatetraene lagern sich im Regelfall bei der elektrophilen Addition in Bicyclo[4.3.1]decatriene um. Das erschließt einen Zugang zu methanoüberbrückten Dihomotropyliumionen. In dieser Arbeit berichten wir über einige substituierte Kationen. Es sind dies das 2-Methyl- (16), 2-Chlor- (22), 2-Brom- (26), 2,5-Dimethyl- (29), 1-Methyl- (37), 1-Chlor- (38), 1-Brom- (39), 7-Phenyl- (42) und 7-(2-Methoxyphenyl)bicyclo[4.3.1]decatrienylkation (44). Die cyclische π-Elektronendelokalisation im Bicyclo[4.3.1]decatrienylkation (1) wird durch die genannten Substituenten mehr oder weniger gestört aber nicht unterbunden.-3-Methyl-bicyclo[4.2.2]decatetraen (30) zeigt bei der HBr-Addition atypisches Verhalten. Nach der Methanolyse liegt 10-exo-Methoxy-4-methyltricyclo[4.3.1.02,9]deca-3,7-dien (33) vor. Eine mechanistische Deutung wird angegeben.
    Additional Material: 1 Tab.
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1976 (1976), S. 793-819 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Aryl Substituted Fulvenes with Tetrachloro-o-quinones2,3,4,5-Tetraarylfulvenes 7 react with the heterodiene moiety of tetrachloro-o-benzoquinone 3 to yield the [2π + 4π] and [6π + 4π] cycloadducts 8 and 9, respectively. The structures of the [2π + 4π] adducts 8 were confirmed by oxidative degradation as well as by their synthesis from 3 with tetraarylcyclopentadienols 6 and from 3 with tetraarylcyclopentadienones (giving 10). The cisoid diene moiety in the [6π + 4π] adducts 9 could be demonstrated by Diels-Alder reaction with 4-phenyl-l,2,4-triazoline-3,5-dione (16) and/or 1,4-phthalazinedione (17). Kinetic measurements (solvent and temperature dependence) on the formation of 8 and 9 are in accord with the assumption of a multicenter cycloaddition reaction with an only moderately polar transition state. - 6,6-Diphenylfulvene gives with 3 an already known [2π + 4π] adduct of type 4 and a spirodioxole 28, the structure of which has been proved by an independent synthesis of the degradation produkt 30. The spirodioxole 28 is presumably formed from an unstable [6π + 4π] adduct of type 5.
    Notes: Bei der Addition von 2,3,4,5-Tetraarylfulvenen 7 an die Heterodieneinheit von Tetrachlor-o-benzochinon (3) werden die [2π + 4π]- und [6π + 4π]-Cycloaddukte 8 bzw. 9 erhalten. Die Strukturen der [2π + 4π]-Addukte 8 werden durch oxidativen Abbau sowie durch Synthese aus 3 mit Tetraarylcyclopentadienolen 6 und aus 3 mit Tetraarylcyclopentadienonen (zu 10) gesichert. Die cisoide Dieneinheit in den [6π + 4π]-Cycloaddukten 9 läßt sich durch Diels-Alder-Reaktion mit 4-Phenyl-1,2,4-triazolin-3,5-dion (16) und/oder 1,4-Phthalazindion (17) nachweisen. Kinetische Untersuchungen (Lösungsmittel- und Temperaturabhängigkeit) zur Bildung von 8 und 9 deuten auf eine Mehrzentrencycloaddition mit nur wenig polarem Übergangszustand hin. - 6,6-Diphenylfulven bildet mit 3 - neben einem bereits beschriebenen [2π + 4π]-Addukt des Typs 4 - ein Spirodioxol 28, dessen Struktur durch eine unabhängige Synthese des Abbauprodukts 30 bewiesen wird. Das Spirodioxol 28 entsteht wahrscheinlich aus einer instabilen [6π + 4π]-Vorstufe des Typs 5.
    Additional Material: 9 Tab.
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 37 (1954), S. 1223-1226 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Der δ-Ketoester 1,1-Dimethyl-2-(β-carbäthoxy-äthyl)-cyclohexanon-(3) wurde durch Kondensation von 1,1-Dimethyl-2-carbäthoxy-cyclohexanon-(3) mit Acrylsäureester und nachfolgende Decarboxylierung hergestellt; daraus wurde durch Verseifung die entsprechende Säure gewonnen.
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  • 9
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 36 (1953), S. 1445-1454 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Es werden vergleichende Versuche über die Sublimations-geschwindigkeit von CsCl, RbCl und KCl beschrieben. Die Abtrennung von CsCl aus äquimolaren Gemischen der Salze durch Sublimation im Vakuum wird untersucht.
    Additional Material: 7 Ill.
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  • 10
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 36 (1953), S. 1820-1832 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Es wurden die Gleichgewichtsdrucke des Wasserstoffs bei der Hydrierung von reinem Calcium im Temperaturbereich von 711-941° bestimmt, unter Verfolgung der Abhängigkeit der Drucke von der Zusammensetzung des Bodenkörpers. Die gemessenen Drucke zeigten weitgehende Übereinstimmung mit den Befunden von Johnson und Mitarbeitern.
    Additional Material: 6 Ill.
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