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  • 1
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal and Molecular Structure of 6-Ethoxy-12,12-dimethyl-dibenzo[d, g]-1,3,2,6-dioxaphosphasilocine 6-OxideThe title compound crystallizes in the monoclinic space group P21/n with lattice parameters a = 824.0(1), b = 2207.5(3), c = 931.1(1) pm, β = 95.50(1)° and a unit cell contents of four molecules. The structures was solved by heavy atom method and refined to R = 0.057 using 1924 observed unique reflections. The eightmembered dioxaphosphasilocine ring adopts an irregular geometry far from any symmetry. The Si atom has an approximately tetrahedral environment whereas the P atom is more distorted tetrahedrally coordinated.
    Notes: Die Titelverbindung kristallisiert in der monoklinen Raumgruppe P21/n mit den Gitterkonstanten a = 824,0(1), b = 2207,5(3) pm, c = 931,1(1) pm, β = 95,50(1)° und vier Molekülen pro Elementarzelle. Die Struktur wurde auf der Grundlage von 1924 beobachteten symmetrieunabhängigen Reflexintensitäten nach der Schweratommethode gelöst und bis zu einem R-Wert von 0,057 verfeinert. Der achtgliedrige Dioxaphosphasilocin-Ring weist eine völlig unregelmäßige Geometrie ohne Symmetrieannäherung auf. Das Si-Atom besitzt in guter Näherung eine regelmäßige tetraedrische Umgebung, das P-Atom ist dagegen stärker verzerrt tetraedrisch koordiniert.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 123 (1990), S. 1733-1737 
    ISSN: 0009-2940
    Keywords: Dithiolactones ; Electroreduction ; Haloalkanedithioates ; Thioacetals, semicyclic ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Intramolecular cyclization occurs on electroreduction of the methyl -haloalkanedithioates 1 in methanol. The expected semicyclic thioacetals 2 are formed according to an ECEH mechanism. The biheterocycles 12 result from dimerization of intermediate radicals whereas the semicyclic ketene dithio-acetals 13 are formed by non-electrochemical processes. The 2-(methylthio)thiolanes 2 a and 16 are obtained with much higher yields and better selectivity by co-electroreduction of the -dithio-lactones 15 in the presence of dimethyl sulfate.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 125 (1992), S. 1641-1646 
    ISSN: 0009-2940
    Keywords: Thioacetals, semicyclic ; Carbanions ; Alkylation ; Hydroxyalkylation ; Diastereoselectivity ; Thiolanes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: C,C Coupling with Sulfur-Stabilized Carbanions, 2[1]. - Reactions of the 2-(Methylthio)thiolane Carbanion with Electrophiles[2]The „semicyclic” thioacetal 2-(methylthio)thiolane (4) is easily prepared from thiolane (tetrahydrothiophene). It is readily deprotonated by butyllithium to give the lithium derivative 5, which reacts with alkyl halides, saturated and α,β-unsaturated carbonyl compounds, and benzonitrile to form the alkyl derivatives 6, carbinols 7, allyl alcohols 8, and - after hydrolysis - the ketone 9. The diastereoselectivity of the C,C coupling reaction is discussed.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 127 (1994), S. 1065-1068 
    ISSN: 0009-2940
    Keywords: Acetals ; Amphiphiles ; Carbohydrates ; Glucosides ; Liquid crystals ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Two new systems of liquid crystalline glucose derivatives 5a-d, 6a, b are prepared, studied and compared with reference compounds. The α- and β-D-dodecyl glucofuranosides 6a, b show smectic A phases. The clearing points of the furanosides are of the same magnitude as those of the pyranosides. The alkyl glucose acetals 5a-d show columnar discotic phases. The clearing points are about 30°C lower than those of the corresponding thioacetals.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and NMR Spectroscopic Investigations of Dibenzo [d,g]-1,3-dioxa-2-element-6-silocineBis-(o-halogenoaroxy)silanes react with sodium via metallation and a fast two-step [1.3]-rearrangement to the sodium salts of bis(o-hydroxyaryl)silanes. These are cyclized in a one-pot-reaction with element halides of silicon, phosphorus and arsenic to the title compounds of the general formula R1R2Si(C6H4O)2E (E = SiR2, P(Y)R, As(Y)R). One conformer is prefered according to N.M.R. spectroscopical investigations.
    Notes: Bis-(o-halogenoaroxy)silane reagieren mit Natrium nach Metallierung im Sinne einer raschen zweifachen [1,3]-Umlagerung zu den Natriumsalzen der Bis-(o-hydroxyaryl)-silane. Im Eintopfverfahren lassen sich diese mit Organoelementhalogeniden des Siliciums, Phosphors und Arsens zu den Titelverbindungen der allgemeinen Formel R1R2Si(C6H4O)2E (E = SiR2, P(Y)R, As(Y)R) cyclisieren. Den NMR-spektroskopischen Untersuchungen entsprechend wird die Bildung eines Konformeren bevorzugt.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 588 (1990), S. 192-198 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: [1.3]-Carbanionic Rearrangements. Synthesis of Bis-(o-hydroxyphenyl) silane DerivativesBis-(o-halophenoxy)silanes react via metallation in a fast two step [1.3]-carbanionic rearrangement to the sodium salts of the bis-(o-hydroxyphenyl)silanes (R1R2Si(o-C6H4ONa)2; R1 = Me, OMe…). These are protolyzed to the free phenols or are giving ethers and esters by reacting with reactive halogen compounds in an one pot reaction.
    Notes: Bis-(o-halophenoxy)silane reagieren mit Natrium nach Metallierung im Sinne einer raschen intramolekularen [1,3]-carbanionischen Umlagerung zu den Natriumsalzen der Bis-(o-hydroxyphenyl)silane (R1R2Si(o-C6H4ONa)2; R1 = Me, OMe…). Diese lassen sich durch Protolyse in die freien Phenole überführen oder im Eintopfverfahren mit reaktiven Halogenverbindungen verestern und verethern.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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