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  • 1975-1979  (94)
  • 1970-1974  (77)
  • 1945-1949  (36)
  • 1920-1924  (86)
  • Chemistry  (293)
  • 1
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 102 (1921), S. 287-294 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 53 (1920), S. 2034-2052 
    ISSN: 0365-9631
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 10 (1971), S. 1351-1364 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The swelling behavior of gelatin gels containing proteoglycans (sulphated proteoglycans from bovine intervertebral discs and a hyaluronate proteoglycan from bovine synovial fluid) when immersed in osmotically active solutions of dextran have been measured. The presence of the proteoglycans markedly affects the internal osmotic contribution to the swelling pressure of the gel. These internal osmotic pressures are considerably in excess of the sum of the osmotic activities of the individual components. This behavior is understood in terms of an entropic interaction between the gelatin and the proteoglycan molecules. By use of the “dilute solution” treatment of Flory, the osmotic pressure excesses are related to the volumes and hence dimensions of the interact acting species. A comparison of these values with those calculated by other means shows good agreement. The osmotic behavior of the complex gels can be understood on a mechanistic basis, if we regard the gelatin and sulphated proteoglycans as spheres and the hyaluronate proteoglycan as a rod.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Light scattered from a macromolecular solution in a capillary tube is used to determine both the sedimentation and translational diffusion coefficients. The capillary tube is spun in a preparative centrifuge, removed, and placed in a light-scattering photometer equipped with a scanning mechanism. The intensity distribution of scattered light along the tube represents the concentration profile in the tube and provides the measure of boundary migration. The sedimentation coefficient is determined from this measure and the applied centrifugal field. The diffusion coefficient is obtained from a time-autocorrelation analysis of fluctuations in intensity of light scattered from any fixed point of the profile. These coefficients were obtained for two monodisperse systems, R17 bacteriophage and 28s ribosomal rat liver RNA. The molecular weights obtained from ratios of these coefficients are in good agreement with literature values. In the sedimentation analysis, deviations from linearity between boundary displacement and applied field were found to be less than 1%. This precision confirms that the boundary is stable for the capillary geometry even in the absence of a preformed density gradient. The sedimentation coefficients of identical samples were also measured with the Spinco Model E analytical ultracentrifuge; results of the two methods agree to within 4%.As a consequence of the capillary tube geometry and light-scattering detection, sedimentation coefficients can be obtained from sample volumes of less than 100 μl. This detection techniques is thus far demonstrated to be at least an order of magnitude more sensitive than Schlieren optics, thereby useful when uv absorption is not applicable. For diffusion measurements there are also several inherent advantages. The diffusion coefficient is obtained from the identical sample, and scanning provides the capability to measure D from various parts of the sedimentation profiles and thereby directly explore concentration dependence, homogeneity, and integrity of the sample. The capillary tube with a layer of silicone oil over the sample and centrifugation provides an effective method to cleanse the solution and trap all dust.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 1792-1796 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Glycosides of Amino Sugars, II. Synthesis of 2-amino-2-deoxy-α-D-glucopyranosidesThe synthesis of glycosides and disaccharides of 2-amino-2-deoxy-D-glucose has been explored using trifluoroacetyl as the N-blocking group. Because of its high tendency for neighboring group participation only β-D-glycosides were formed. The corresponding α-disaccharide could be obtained as the main product when employing 2.4-dinitrophenyl as the N-protecting group.
    Notes: Die N-Trifluoracetyl-Schutzgruppe wurde zur Synthese von Glykosiden und Disacchariden der 2-Amino-2-desoxy-D-glucose benutzt. Sie zeigte eine hohe Tendenz zur Nachbargruppen-beteiligung unter Bildung von -β-D-Glykosiden. Das entsprechende α-Disaccharid wurde als Hauptprodukt bei Verwendung der N-2.4-Dinitrophenyl-Schutzgruppe erhalten.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 2424-2427 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Di- and Polyamino Sugars, XV. XIV. Mitteil.: W. Meyer zu Reckendorf, Tetrahedron Letters [London] 1970, 287. Synthese der 2.4-Diamino-1.6-anhydro-2.4-dideoxy-D-talose. Synthesis of 2,4-Diamino-1,6-anhydro-2,4-dideoxy-D-taloseDehydrogenation of the amino reductone 1 with iodine yields a triulose which is isolated as the phenylhydrazone-phenylazo derivative 2. Spontaneous cyclization of 2 forms the 1.6-anhydro compound 3. On hydrogenation 2as well as 3are transformed into the title compound.
    Notes: Die durch Dehydrierung des Aminoreduktons 1 mit Jod entstehende Triulose wird als Bis-phenylhydrazon 2 isoliert, das die Konstitution eines Phenylhydrazon-benzolazo-Derivates besitzt. 2 cyclisiert leicht zur 1.6-Anhydro-Verbindung 3, die, wie auch 2, bei der katalytischen Hydrierung die Titelverbindung liefert.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 2084-2090 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Condensations of Cyclic Aryl-conjugated α-Bromoketones with FormaldehydeReactions of carbocyclic and heterocyclic α-bromoketones with formaldehyde yield α-epoxy-α-methylketones or α, β-unsaturated α-(hydroxymethyl)ketones.
    Notes: Die Umsetzung einer Reihe von carbocyclischen und heterocyclischen α-Brom-ketonen mit Formaldehyd ergibt α-Epoxy-α-methyl-ketone oder α. β-ungesättigte α-Hydroxymethyl-ketone.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 673-685 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of 2.-3(Carboxymethylene)- and 2.-3(2-Hydroxyethylidene)-2.3-dideoxy-D-mannose  -  Monosaccharides with a Cyclopropane RingThe anhydro derivative 1 yielded the cyclopropane carboxylic ester 2 in a PO-activated olefination reaction. Under mild conditions 2 could be hydrolised to the free carboxylic acid 5. By reduction the cyclopropyl carbinol 13 and the cyclopropane carbaldehyde 21 were formed. The latter could be rearranged to the cyclobutene derivative 25. Attempts to synthesize a cyclopropanol were unsuccessful.
    Notes: Durch PO-aktivierte Olefinierung entstand aus der Anhydro-Verbindung 1 der Cyclopropancarbonsäureester 2, der unter milden Bedingungen zur freien Carbonsäure 5 hydrolysiert werden konnte. Reduktion lieferte das Cyclopropylcarbinol 13 und den Cyclopropan-carbaldehyd 21, der zum Cyclobutenderivat 25 umgelagert wurde. Die Synthese eines Cyclopropanols gelang nicht.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 3397-3411 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Di-and Polyamino Sugars, XXI. Synthesis of Derivatives of 2,4-Diamino-2,3,4-trideoxy-D-ribo-hexoseStarting with D-glucose the title compound has been synthesized as its di-N-acetyl. -trifluoroacetyl and N,N′-bis(2,4-dinitrophenyl) derivative. The free sugar could not be obtained in a pure state.
    Notes: Die Titelverbindung wurde, ausgehend von D-Glucose, in Form ihres Di-N-acetyl-, -trifluoracetyl- und ihres N,N′-Bis(2,4-dinitrophenyl)-Derivates erhalten. Reindarstellung des freien Zuckers gelang nicht.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 108 (1975), S. 3596-3610 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Heterocyclic Seven-membered Ring Compounds, XVI. Synthesis of 3,5-Substituted 4-Phenyl-1-benzothiepins4-Phenyl-1-benzothiepins 7 and 8 are synthesized starting from their 5-methoxy-2,3-dihydro-precursor 2; using the 2,5-dihydro-intermediate 12 yields the 4-phenyl-1-benzothiepins 13 and 14. The 1-benzothiepin 17 can be obtained from the diketone 1 directly. The 3-cyano-substituted compound 22 is prepared from its 2,5-dihydro-precursor 21. Some ring-contraction and ring-cleavage reactions of the heterocyclic seven-membered ring-system are described.
    Notes: Die 5-Methoxy-2,3-dihydro-Vorstufe 2 wird in die 4-Phenyl-1-benzothiepine 7 und 8 übergeführt; aus der 2,5-Dihydro-Vorstufe 12 werden die 4-Phenyl-1-benzothiepine 13 und 14 dargestellt. Das 1-Benzothiepin 17 wird direkt aus dem Siebenring-Diketon 1 erhalten. Das 3-cyan-substituierte 1-Benzothiepin 22 erhält man aus der 2,5-Dihydro-Vorstufe 21. Es werden einige Ringverengungsbzw. Ringspaltungsreaktionen des heterocyclischen Siebenring-Systems beschrieben.
    Type of Medium: Electronic Resource
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