Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Chemie und Stereochemie der Iridoide, III. Über die Synthese von 12-epi-Prostaglandinen (1983)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1983 (1983), S. 2197-2214 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Chemistry and Stereochemistry of Iridoids, III. - About the Synthesis of 12-epi-ProstaglandinsA general applicable synthetic route to 12-epi-prostaglandins, which are difficult to prepare by known syntheses, is described. As examples the 12-epi-PGF2β (11) and its 15R epimer are synthesized. By alteration of the synthesis the already known PGF2β (11a) and its 15 R epimer can be prepared. The configurations of the obtained prostaglandins are established chemically and spectroscopically.
    Notes: Es wird ein allgemein anwendbarer Syntheseweg zu 12-epi-Prostaglandinen beschrieben, die nach den bekannten Synthesen nur schwer herstellbar sind. Als Beispiel wird das 12-epi-PGF2ß (11) und sein 15R-Epimeres synthetisiert. Durch Abwandlung der Synthese kann auch das schon bekannte PGF2β (11a) und sein 15R-Epimeres hergestellt werden. Die Konfigurationen der erhaltenen Prostaglandine werden chemisch und spektroskopisch bewiesen.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198319831215
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Hydroperoxide-initiated copolymerization of sulfur dioxide and cyclohexene. I. Characterization of charge-transfer complex and initiation (1977)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 15 (1977), S. 2479-2495 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The copolymerization of cyclohexene and sulfur dioxide to form an alternating copolymer was initiated by tert-butyl hydroperoxide. The enthalpies and entropies of formation of the cyclohexene-sulfur dioxide charge-transfer complex, which is present during the copolymerization, were determined in two solvents by means of ultraviolet spectroscopy. The reduction of ultraviolet absorption during copolymerization afforded a convenient means of investigating reaction kinetics. No evidence of the direct involvement of the complex in polymerization initiation was found. The observation that the use of unpurified cyclohexene led to spontaneous initiation appears to point to adventitiously formed hydroperoxide rather than the charge-transfer complex as providing initiating radicals which are produced by the redox reaction of the hydroperoxide with sulfur dioxide. A competing heterolytic scission reaction was found to result in the formation of tert-butyl peroxide and sulfuric acid. This reaction caused the polymerization reaction to stop after a short period of time due to a time-dependent decrease in initiator concentration.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1977.170151017
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Preparation of triblock styrene-tert-butylstyrene-styrene copolymers by living radical polymerization with a heterogeneous polymeric initiator (1978)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 16 (1978), S. 469-474 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Triblock copolymers containing the sequence styrene, p-tert-butylstyrene, styrene were prepared in an emulsion system by using isotactic polypropylene hydroperoxide as the initiator together with triethylenetetramine as an activator, according to the method of Mikulasova and co-workers. Polymerization of styrene continued after removal of the initiator from the emulsion by filtration and eventually reached 100% conversion after 4 hr at 35°C. tert-Butylstyrene at 80°C and styrene at 35°C were added successively to the system, with each polymerization reaction carried to 100% conversion before the next monomer was added. Thin-layer chromatography was used to separate the homopolymers and block copolymers in order to determine the purity of the product. Monomer compositions of the block copolymers was verified by infrared analysis. The existence of two separate phases in the extracted block copolymer was indicated by the observation of two distinct glass transition temperatures.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1978.170160217
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...