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  • 1
    ISSN: 0009-2940
    Keywords: AM1 calculations ; Chloralide ; Dioxolane ; Force-field calculations ; Tartaric acid ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Isolation of a third diastereoisomer (1c) of (R,R)-tartaric acid chloralide is described. A comparison of structural data derived by X-ray analysis with calculated parameters is given. Structures are generated by the ALCHEMY force-field program as well as by AM1 calculations.
    Additional Material: 3 Ill.
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  • 2
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses with Aliphatic Dialdehydes, XXXIX. The Conformation of Trinuclear [2.2.2]Heptamethinediium Cyanine Dyes with Indoline End GroupsAccording to ESR and ESCA spectroscopic measurements as well as X-ray analyses the [2.2.2]-heptamethinediium cyanine dyes 1 and 2 exist in the crystalline state and probably in solution as vinylogous amidinium ions (γ-substituted pentamethine cyanine or dicarbocyanine dyes) 1b and 2a.
    Notes: Nach ESR- und ESCA-spektroskopischen sowie röntgenographischen Befunden liegen die [2.2.2] Heptamethindiium-Cyaninfarbstoffe 1 und 2 in kristalliner Form und wahrscheinlich auch in Lösung nicht - wie bislang angenommen - als methinyloge Guanidinium-Ionen 1a und 2a vor, sondern als vinyloge Amidinium-Ionen (γ-substituierte Pentamethincyanin oder Dicarbocyaninfarbstoffe (1b und 2b.
    Additional Material: 2 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 1371-1382 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reaction of Organic Thiocyanates, Selenocyanates, and Cyanates with Malonyl ChlorideOrganic thiocyanates and selenocyanates react with malonyl chloride to form the pyrano-oxazinediones 1a, b and 2 a, b. Compound 4 is obtained in the case of phenacyl thiocyanate. With the exception of compound 6, nucleophilic substitution of the bromine atom in compound 1 a is not possible. Excess n-propylamine leads to 7, while reaction in acidic medium gives 5. The reaction product of malonyl chloride and aromatic cyanates is strongly dependent on the reaction conditions. At temperatures up to + 20°C, β-lactams 8a - g and hydrolysis products 9 a - e, respectively, are formed. At 30 - 70°C substances 11a, d - f, at 60 - 90°C cyclization products 10a, d - g, and at temperatures of approx. 120°C decarboxylation products 12a, b, d are formed. An X-ray structural analysis is made of 9b.
    Notes: Organische Thio- und Selenocyanate reagieren mit Malonylchlorid zu den Pyrano-oxazindionen 1a, b und 2a, b; im Falle von Phenacylthiocyanat entsteht 4. Nucleophile Substitution des Bromatoms in 1a ist außer zu Verbindung 6 nicht möglich, ein Überschuß an n-Propylamin führt zu 7, während Umsetzung in saurem Medium 5 ergibt. Das Reaktionsprodukt von Malonylchlorid und aromatischen Cyanaten ist stark abhängig von den Reaktionsbedingungen - bei Temperaturen bis + 20°C entstehen die β-Lactame 8a-g bzw. die Hydrolyseprodukte 9a-e, bei 30 - 70°C die Substanzen 11a,d - f, bei 60 - 90°C die Cyclisierungsprodukte 10a, d - g und bei Temperaturen von ca. 120°C die Decarboxylierungsprodukte 12a, b, d. Von 9b wird eine Röntgenstruktur-analyse durchgeführt.
    Additional Material: 5 Tab.
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 1857-1867 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Regiochemistry of the Intermolecular [8 + 2] Cycloaddition of Electron-rich Heptafulvenes: Syntheses of 1,2,3-Trisubstituted Hydroazulenes[8 + 2] Cycloadditions of 8-methoxyheptafulvene (1) with activated and electron-poor polyenophiles 2 occur regiospecifically linking C-1 (C-6) of 1 and C-1 of 2 and C-8 of 1 and C-2 of 2, respectively. Diastereomeric mixtures of hydroazulenes are formed. Assignments of the structures by 1H NMR utilize the „stereochemically fixed“ five-membered rings. It is concluded that the [8 + 2] cycloadditions are controlled by the coefficients of the atomic orbitals.
    Notes: 8-Methoxyheptafulven (1) addiert Dicyanalkene und Nitroalkene 2 regiospezifisch unter Bildung der Hydroazulene 4 - 8. Die Verknüpfung erfolgt zwischen dem exocyclischen Kohlenstoff C-8 des Heptafulvens 1 und C-2 von 2, sowie zwischen C-1 von 2 und C-1 (C-6) von 1. Die [8 + 2]-Cycloadditionen verlaufen nicht stereospezifisch. Strukturzuordungen für die Hydroazulene erfolgten durch 1H-NMR-Spektren und chemische Reaktionen. Bei der Interpretation der Stereochemie im Fünfring wurde vorausgesetzt, daß Phenylgruppen das sonst flexible Ringsystem fixieren. Eine Betrachtung mit der MO-Therapie ergibt: Die Regiochemie der [8 + 2]-Cycloaddition resultiert aus der Kontrolle durch die Atomorbital-Koeffizienten.
    Additional Material: 2 Tab.
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 401-402 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis of a Tricabonyl (η5-2,3-dihydro-1H-1,3-diborolyl)cobalt ComplexReactions of 1,3,4,5-tetraethyl-2,3-dihydro-2-methyl-1H-1,3-diborole (1) with Co2(CO)8, HCo(CO)4, and (η3-C3H5)Co(CO)3 result in the formation of the tricarbonyl(η5-2,3-dihydro-1H-1,3-diborolyl)cobalt 3 in 6, 16, and 61% yield, respectively. The heterocycle of the yellow, air-sensitive 3, acts as a 3e-donor ligand.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 413-427 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 3,4-Dihydroisoquinolines, I. 5,6-Dihydropyrrolo[2,1-a]isoquinolines via Rearrangement of 1-(3-Furyl)-3,4-dihydroisoquinolinesA new synthesis of 5,6-dihydropyrrolo[2,1-a]isoquinolines 2 via base-catalysed ring transformation of 1-(3-furyl)-3,4-dihydroisoquinolines 1 has been developed. The structure of 2 was derived from spectroscopic data and reaction products. A pathway for the formation of 2 is discussed.
    Notes: Durch basenkatalysierte Umlagerung der leicht zugänglichen 1-(3-Furyl)-3,4-dihydroisochinoline 1 wurde ein neuer Syntheseweg für 5,6-Dihydropyrrolo[2,1-a]isochinoline 2 erschlossen. Die Struktur der Verbindungen 2 wird unabhängig von den spektroskopischen Befunden anhand ihrer Folgeprodukte abgeleitet. Der Reaktionsmechanismus der Bildung von 2 wird diskutiert.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 4725-4742 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stepwise Oxidation of 1,2-Naphthoquinone and Cyclohepta[de]naphthalene-7,8-dione (o-Pleiadienequinone)Oxidation of cyclohepta[de]naphthalene-7,8-dione (o-pleiadienequinone) (1) and o-naphtho-quinone (2) yields the corresponding epoxides 14 and 3, respectively. The stepwise oxidation of 3 yields derivatives of 1,2,3,4-tetraoxonaphthalene, while the stepwise oxidation of 14 finally results in the formation of phenalenetrione or phenalenone derivatives.
    Notes: Durch Oxidation von Cyclohepta[de]naphthalin-7,8-dion (o-Pleiadienchinon) (1) und o-Naphthochinon (2) werden die entsprechenden Epoxide 14 und 3 erhalten. Die stufenweise Oxidation von 3 führt zu Derivaten des 1,2,3,4-Tetraoxonaphthalins, die stufenweise Oxidation von 14 gibt dagegen unter Ringverengung Derivate des Phenalentrions bzw. Phenalenonderivate.
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 1917-1926 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Electronic Structure of 1,4-Disubstituted ButanetetronesThe He(I) photoelectron (PE) spectra of the disubstituted butanetetrones 1 a - e have been recorded. The assignment of the first PE bands is based on semiempirical calculations. For 1 a - e the first bands could be assigned to ionization events from lone pair combinations on the oxygen atoms and in the case of 1 b - e additionally to ionizations from π-orbitals localized on the aromatic rings. The comparison between the PE bands of 1 d, 1,3-diphenyl-1,2,3-propanetrione, benzil, and benzophenone yields the result that the energy split between the n-orbital energies con-verges towards a value of about 3 eV. The interactions among the lone pairs and between lone pairs and the σ frame in 2 b - d are discussed, based on INDO calculations using localized orbitals.
    Notes: Die He(I)-Photoelektronen(PE)-Spektren der 1,4-disubstituierten Butantetrone 1 a - e wurden gemessen und anhand semiempirischer Rechnungen zugeordnet. Bei 1 a - e wurden die ersten Banden Ionisationen aus Linearkombinationen der einsamen Elektronenpaare an den Sauerstoffen und im Fall von 1 b - e noch zusätzlich Ionisationen aus den aromatischen π-Orbitalen zugeordnet. Der Vergleich zwischen den PE-Banden von 1 d, 1,3-Diphenyl-1,2,3-propantrion, Benzil und Benzophenon zeigt, daß die Aufspaltung zwischen den n-Orbitalenergien einem Grenzwert von etwa 3 eV zustrebt. Die Wechselwirkung zwischen den n-Orbitalen, den n-Orbitalen und dem σ-Gerüst (Through-Space- und Through-Bond-Wechselwirkung) in den vic. Di-, Tri- und Tetra-ketonen 2 b - d wird anhand von lokalisierten Orbitalen, die nach der INDO-Methode erhalten werden, diskutiert.
    Additional Material: 7 Ill.
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 2314-2329 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Regio- and Stereoselectivity of the Metal-induced Ring Opening of Di- and Tetramethylspiro[2.4]-hepta-4,6-dienesMetal-induced ring opening of spiro[2.4]hepta-4,6-dienes was investigated using nickel, molybdenum, and iron carbonyls for 1,1-dimethyl- (4), 1,1,2,2-tetramethyl- (5), and the E- and Z-isomers of 1,2-dimethylspiro[2.4]hepta-4,6-diene (6). The reactions partially yielded labile product mixtures and therefore caused difficulties towards a clear interpretation of the results. While the products obtained with molybdenum and nickel carbonyls suggest a normal opening of the sterically less hindered cyclopropane bond and retention of configuration, the complexes found with iron carbonyls indicate a new, hitherto not observed reaction course involving cleavage of the exo-CC bond of the cyclopropane ring without retention of configuration.
    Notes: Die Regio- und Stereoselektivität der metallinduzierten Ringöffnung von Spiro[2.4]hepta-4,6-dienen wurde mit Nickel-, Molybdän- und Eisencarbonylen an 1,1-Dimethyl- (4), 1,1,2,2-Tetramethyl- (5) sowie an den E- und Z-Isomeren des 1,2-Dimethylspiro[2.4]hepta-4,6-diens (6) untersucht. Die Umsetzungen ergaben teilweise labile Produktgemische, die eine klare Interpretation der Resultate erschweren. Während die mit Molybdän- und Nickelcarbonylen erhaltenen Produkte auf eine normale Öffnung der sterisch weniger gehinderten Dreiringbindung und Konfigurationserhalt schließen lassen, geben die mit Eisencarbonylen gefundenen Komplexe Hinweis auf einen neuen, bisher nicht beobachteten Reaktionsverlauf über eine Öffnung der exo-CC-Bindung des Cyclopropansystems, die ohne Konfigurationserhalt verläft.
    Additional Material: 1 Tab.
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 2561-2564 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis of 1λ6, 2, 6-Thiadiazines by Condensation with S, S-Dialkylsulfur DiimidesReaction of S, S-dialkylsulfur diimides 1 a-e with diketene leads to the colourless 1λ6, 2, 6-thiadiazine compounds 3 a-e. They can also be prepared by condensation of ethyl aceto acetate (5) with 1 a, b. 5-Aryl-substituted 1λ6, 2, 6-thiadiazines 7 a, b are synthesized by cyclisation of 1 a, b with 6. Bromination of 3 a to 4 is described.
    Additional Material: 2 Tab.
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