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  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 109 (1976), S. 1887-1897 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Reactions of Octamethylbicyclo[4.2.0]octa-2,4,7-trieneThe synthesis of the title compound 2 from octamethylcyclooctatetraene (1) is described. The kinetic data for the rearrangement of 2 to 1 are given. 2 cycloadds to several dienophiles already at 0°C to yield 12, 13, the formation of which from 1 requires substantially higher temperatures. - Two cycloadducts of octamethylsemibullvalene (3) previously were attributed structures corresponding to 12-13; they have now been shown to be 16 and 17. - The facile elimination of nitrogen from azo compound 19 is interpreted as a concerted cycloreversion.
    Notes: Die Titelsubstanz 2, deren Synthese ausgehend von Octamethylcyclooctatetraen (1) beschrieben wird, lagert sich oberhalb von 0°C in 1 um. Die kinetischen Parameter dieser Reaktion wurden bestimmt. 2 liefert mit verschiedenen Dienophilen bereits bei 0°C die Addukte 12, 13, zu deren Bildung aus 1 wesentlich höhere Temperaturen notwending sind. - Früher beschriebenen Cycloaddukten von Octamethylsemibullvalen (3), für welche eine obigen Addukten entsprechende Struktur angenommen wurde, kommt in Wirklichkeit die Konstitution 16 bzw. 17 zu. - Die leichte Stickstoffeliminierung der Azoverbindung 19 wird als einstufige Cycloreversion erklärt.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1986 (1986), S. 1074-1097 
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Rearrangements of 2,3-Diazabicyclo[2.2.2]octane DerivativesThe ketones 4a - e have been synthesized and their reactions with methylmagnesium iodide were studied. A mechanism is given for the rearrangement of some magnesium alkoxides to 6,7-diazabicyclo[3.2.1]octane derivatives. - Dehydration of the alcohols 12d, 14a; 17a, b, g, and h with trichlorophosphane oxide is accompanied by migration of the group antiperiplanar to the hydroxy function, and thus 6,7-diazabicyclo[3.2.1]octane derivatives are formed. - Ketones 4a, c and e give on sensitized irradiation the tricyclooctane derivatives 40a, b and d, respectively, while direct irradiation leads to the bicycloheptane derivatives 42a, b and d, respectively.
    Notes: Die Darstellung der Ketone 4a - e sowie deren Umsetzung mit Methylmagnesiumiodid werden beschrieben. Für die bei einigen dieser Grignard-Additionen auftretende Umlagerung zum 6,7-Diazabicyclo[3.2.1]octan-System wird ein Mechanismus aufgestellt. - Die Dehydratisierung der Alkohole 12d, 14a, 17a, b, g und h mit Trichlorphosphanoxid erfolgt unter stereokontrollierter Umlagerung zum Bicyclo[3.2.1]octan-System mit Wanderung der zur Hydroxyfunktion antiperiplanaren Gruppierung. - Je nach Belichtungsbedingungen erhält man bei der Photoisomerisierung von 4a, c und e die Tricyclooctan-Derivate 40a, b bzw. d oder die Bicycloheptan-Derivate 42a, b bzw. d.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1986 (1986), S. 1104-1108 
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactions of 3,7,7-Trimethyl-4-methylenebicyclo[4.1.0]hept-2-ene with DienophilesThe preparation of the title compound 2b is described. Treatment of 2b with some dienophiles leads to the adducts 4a, b and 6b, c via ene reactions. 2b can be rearranged to give the cycloheptatriene 8.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1986 (1986), S. 1098-1103 
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1,2,3,4,5,5-Hexamethyl-6-methylenecyclohexa-1,3-diene and 1,2,3,4,4,5-Hexamethyl-6-methylenebicyclo[3.1.0]hex-2-eneThe title compounds 3 and 5, respectively, have been synthesized. On treatment of 3 with acids rapid isomerization to 2 takes place. Rearrangement of 5 to homofulvene 4 occurs at 60°C within 3 hours.
    Type of Medium: Electronic Resource
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