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  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 117 (1984), S. 666-671 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: (Z)-/(E)-2,2,2',2'-Tetraethoxy-Δ3,3'(2H, 2'H)-bi[phenanthro[9,10-b]furan], II1). Synthesis and Structure Determination of some Phenantro-condensed O-HeterocyclesIn the absence of water the proton- or bromine-catalyzed isomerization of the pure diastereomers 1 leads to a mixture of the Z/E-isomers 2a. Acidic hydrolysis of these two diastereomers yields fumaric ester 4, which readily undergoes thermal cyclizitation to give coumarin 5a. - Direct acidic hydrolysis of the Z/E-isomers 1 forms orthoester 3 and fumaric ester 4. - Alkaline hydrolysis of coumarin 5b gives salt 5c, which on acidification forms carboxylic acid 5d. Heating of 5d in the presence of thionyl chloride leads to coumarino-coumarin 6. - Heating of coumarin 5b gives the furo-coumarin 7. 7 is also formed on heating of coumarino-coumarin 6 in the presence of water.
    Notes: Unter Ausschluß von Wasser führt die Protonen- bzw. Brom-katalysierte Isomerisierung der reinen Diastereomeren 1 zu dem Z/E-Isomerengemisch 2a. Die saure Hydrolyse dieser beiden Diastereomeren liefert den Fumarsäurediester 4, der thermisch zu dem Cumarin 5a cyclisiert. - Bei der direkten sauren Hydrolyse der Z/E-Isomeren 1 isoliert man den Orthoester 3 und den Fumarsäurediester 4. - Die alkalische Hydrolyse des Cumarins 5b gibt das Salz 5c, das durch Ansäuern die Carbonsäure 5d liefert. Beim Erhitzen von 5d in Thionylchlorid erhält man das Cumarino-cumarin 6. - Bei der thermischen Belastung entsteht aus dem Cumarin 5b das Furocumarin 7. In Anwesenheit von Wasser bildet sich 7 auch beim Erhitzen des Cumarino-cumarins 6.
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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 Alkenediazonium Salts, V. Synthesis and Structure of 1,3,4-Oxadiazoles, 6H-1,3,4-Oxadiazines, and 5,6-Dihydro-4H-1,3,4-oxadiazinesDepending on the substituents R1 and R2 the reaction of alkenediazonium salts 1 with carboxylic hydrazides 2 leads to 1,3,4-oxadiazoles 6, 6H-1,3,4-oxadiazines 7, and 5,6-dihydro-4H-1,3,4-oxadiazines 8, respectively. The structures of 6b, 7Be, and 8b were established by X-ray analysis.
    Notes: Die Umsetzung von Alkendiazoniumsalzen 1 mit Carbonsäurehydraziden 2 führt in Abhängigkeit von den Substituenten R1 und R2 zu 1,3,4-Oxadiazolen 6, 6H-1,3,4-Oxadiazinen 7 bzw. zu 5,6-Dihydro-4H-1,3,4-oxadiazinen 8. Zur Sicherung der Konstitution von 6b, 7Be und 8b wurden Röntgenstrukturanalysen durchgeführt.
    Additional Material: 1 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 113 (1980), S. 3477-3487 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Push-Pull Substituted Allenes, VI. Synthesis and Properties of 1,1-Diethoxy-3-acylallenesReaction of the non enolizing 1,2-diketones 1 with (2,2-diethoxyvinylidene)triphenylphosphorane (2) yields the 1,1-diethoxy-3-acylallenes 4 via the remarkably stable oxaphosphetanes 3. With two exceptions these allenes dimerize spontaneously to form the polycycles 5. Their acidic hydrolysis leads to the laser dyes 6. If the allenes 4 are generated in situ and trapped with ethanol, one isolates the orthoesters 9, whereas with water, benzoyl chloride and ethyl chloroformate α,β-unsaturated γ-keto esters 10 are formed.
    Notes: Bei der Umsetzung der nicht enolisierenden 1,2-Diketone 1 mit (2,2-Diethoxyvinyliden)triphenylphosphoran (2) entstehen über die auffallend stabilen Oxaphosphetane 3 die 1,1-Diethoxy-3-acylallene 4, die bis auf zwei Beispiele spontan zu den Polycyclen 5 dimerisieren. Durch saure Hydrolyse erhält man daraus die Laserfarbstoffe 6. Beim Abfangen der in situ erzeugten Allene 4 mit Ethanol isoliert man die Orthoester 9, während mit Wasser, Benzoylchlorid bzw. Chlorameisensäure-ethylester die α,β-ungesättigten γ-Ketoester 10 gebildet werden.
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 114 (1981), S. 2661-2664 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Cumulated Ylides, XI. Reaction of Isocyanates and Isothiocyanates with (2,2-Diethoxyvinylidene)triphenylphosphorane(2,2-Diethoxyvinylidene)triphenylphosphorane (8) reacts with isocyanates and isothiocyanates 1 to give 1,3-disubstituted 6,6-diethoxy-5,6-dihydro-5-(triphenylphosphoranylidene)-2,4(1H,3H)-pyrimidinediones and -dithiones 13, respectively. By boiling in acetic acid the acetal group of 13 is cleaved with formation of the corresponding 6-oxo derivatives 14.
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 117 (1984), S. 1246-1249 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Syntheses with Alkenediazonium Salts, III. ω,ω′-Di-1H-1,2,3-triazolylalkanes from Ethenediazonium Hexachloroantimonates and ω,ω′-DiaminoalkanesReaction of the ethenediazonium hexachloroantimonates 2 with ω,ω′-diaminoalkanes 3 leads to ω,ω′-di-1H-1,2,3-triazolylalkanes 5.
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  • 6
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Photoelectron Spectrum of 1,1-Diethoxy-3,3-bis(trifluoromethyl)allene. The Effect of Trifluoromethyl Groups on Cumulative SystemsThe He(I) photoelectron(PE) spectra of 1,1-diethoxy-4,4,4-trifluoro-3-(trifluoromethyl)-1,2-butadiene [1,1-diethoxy-3,3-bis(trifluoromethyl)allene] (1), tetraethoxyallene (3), and tetrakis-(trifluoromethyl)allene (5) have been recorded. A comparison between the PE spectra of 1, 3, and 5 shows that the first band of 1 (8.93 eV) is due to an ionization from the diethoxyethylene fragment and the second band of 1 (11.0 eV) is due to ionization from the bis(trifluoromethyl)-ethylene fragment. The effect of CF3 groups has also been discussed by comparing the PE spectra of bis(trifluoromethyl)ketene (6) and bis(trifluoromethyl)thioketene (7) with the parent compounds. The interpretation is aided by comparing the measured ionization potentials with orbital energies derived from a MINDO/3 or MNDO calculation.
    Notes: Die He(I)-Photoelektronen(PE)-Spektren von 1,1-Diethoxy-4,4,4-trifluor-3-(trifluormethyl)-1,2-butadien [1,1-Diethoxy-3,3-bis(trifluormethyl)allen] (1), Tetraethoxyallen (3) und Tetrakis-(trifluormethyl)allen (5) wurden gemessen. Der Vergleich zwischen den PE-Spektren von 1, 3 und 5 zeigt, daß das 1. Ionisationspotential von 1 (8.93 eV) der Ionisation aus dem Diethoxyethylen-Fragment, das 2. Ionisationspotential von 1 (11.0 eV) der Ionisation aus dem Bis(trifluormethyl)ethylen-Fragment entspricht. Der Effekt der CF3-Gruppen wird zusätzlich anhand eines Vergleichs der PE-Spektren von Bis(trifluormethyl)keten (6) und Bis(trifluormethyl)thioketen (7) mit den unsubstituierten Verbindungen diskutiert. Die Interpretation erfolgt durch Vergleich zwischen den gemessenen Ionisationspotentialen und berechneten Orbitalenergien nach der MINDO/3-oder MNDO-Methode.
    Additional Material: 4 Ill.
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 2150-2155 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Push-Pull Substituted Allenes, VIII. 1,2-Bismethylenecyclobutanes and Pyrano-pyrans: Dimers from Differently Substituted Donor/Acceptor AllenesDepending on the substituents donor/acceptor-substituted allenes dimerize to give two different classes of compounds: 1,1-diethoxy-3,3-bis(trifluoromethyl)allene (4) in a [2 + 2]-cyclodimerization gives 1,2-bismethylenecyclobutane 5 and 1,1-diethoxy-3-acylallene 13 dimerizes with substituent participation in a hetero Diels-Alder reaction and subsequent electrocyclic ring closure reaction to give pyrano 14.
    Additional Material: 1 Ill.
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 2626-2634 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses with Alkenediazonium Salts, IV 1H-1,2,3-Triazoles, 2-Diazoimines, and Imido Esters from Alkenediazonium Salts and Primary Amines, Hydrazines, and Hydroxylamine EthersReaction of alkenediazonium salts 1 with „amines“ 2 (primary amines, hydrazines, hydroxylamine ethers) leads to 2-diazoimines 4, 1H-1,2,3-triazoles 6, and imido esters 8 and 9, respectively, depending on the substituents R. Condensation of 1-amino-1H-1,2,3-triazole 6Ceα with acetone yields hydrazone 13.
    Notes: Die Umsetzung von Alkendiazoniumsalzen 1 mit „Aminen“ 2 (primäre Amine, Hydrazine, Hydroxylaminether) führt in Abhängigkeit der Substituenten R zu 2-Diazoiminen 4, 1H-1,2,3-Triazolen 6 bzw. Imidoestern 8 und 9. Kondensation von 1-Amino-1H-1,2,3-triazol 6 Ceα mit Aceton liefert das Hydrazon 13.
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  • 9
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Push-Pull Substituted Allenes, IV1). Synthesis and Properties of o-Quinoid Donor/Acceptor Substituted Allenes Crystal- and Molecule Structure of E-2,2,2′,2′-Tetraethoxy-Δ3,3′(2H,2′H)-bi[phenanthro[9,10-b]furan]Reaction of the (2,2-diethoxyvinylidene)triphenylphosphorane (7) with the o-quinones 6 yields the donor/acceptor allene intermediates 9 via the oxaphosphetanes 8. The allenes 9 give the carbenes 10 which then spontaneously dimerize forming the olefins 11. The temperature dependence of the 1H NMR spectra leads to insights into the diastereomerization of the torsionally distorted olefins 11b and the conformational mobility of the E-isomer. Acidic hydrolysis of the Z/E-isomeric orthoesters 11a leads to the monolactone 12 and the bislactone 13. The monomers 9/10 can be trapped by triphenylphosphane affording the orthoester-phosphoranes 14 which under elimination of ether give the phosphoranes 16. The structure of the E-dimer 11 b has been determined from X-ray data.
    Notes: Bei der Umsetzung des (2,2-Diethoxyvinyliden)triphenylphosphorans (7) mit den o-Chinonen 6 entstehen über die Oxaphosphetane 8 intermediär die Donor/Akzeptor-Allene 9. Diese gehen in die Carbene 10 über, die dann spontan zu den Olefinen 11 dimerisieren. Die Temperaturabhängigkeit der 1H-NMR-Spektren liefert Einblick in die Diastereomerisierung der verdrillten Olefine 11b und die konformative Beweglichkeit des E-Isomeren. Die saure Hydrolyse der Z/E-isomeren Orthoester 11a führt über das Monolacton 12 zu dem Bislacton 13. Die Monomeren 9/10 lassen sich mit Triphenylphosphan unter Bildung der Orthoester-phosphorane 14 abfangen, die sich durch Eliminierung von Ether zu den Phosphoranen 16 stabilisieren. Die Struktur des E-Dimeren 11b wurde röntgendiffraktometrisch bestimmt.
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 116 (1983), S. 1463-1467 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 4-Ylidenebutenolide Syntheses, I. Simple Synthesis of Unsaturated Bicyclic Orthoesters and Their Acidic Hydrolysis to Fused 4-Alkylidene-2-buten-4-olidesReaction of (2,2-diethoxyvinylidene)triphenylphosphorane (4) with enolizing cyclic 1,2-diketones 5 via the (2,2-diethoxyvinyl)triphenylphosphonium enolates 8 yields the orthoester phosphoranes 11, which in an intramolecular Wittig reaction spontaneously give the fused orthoesters 7, whose acidie hydrolysis affords the 4-alkylidene-2-buten-4-olides 2.
    Notes: Bei der Umsetzung des (2,2-Diethoxyvinyliden)triphenylphosphorans (4) mit den enolisierenden cyclischen 1,2-Diketonen 5 entstehen über die (2,2-Diethoxyvinyl)triphenylphosphonium-enolate 8 die Orthoesterphosphorane 11. Diese liefern spontan in einer intramolekularen Wittig-Reaktion die anellierten Orthoester 7, deren saure Hydrolyse glatt zu den 4-Alkyliden-2-buten-4-oliden 2 führt.
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