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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

THERMAL RING OPENING OF CYCLOPROPANES AS INITIATORS FOR POLYMERIZATION

Willis, Terrance James, 1959- January 1987 (has links)
Donor-Acceptor tetramethylenes have been studied by polymerizations. 1,4-Zwitterionic intermediates are indicated when reactive tetramethylenes initiate homopolymerization. Alternately, 1,4-diradical intermediates initiate copolymerization. This basis for studying intermediates has led to an empirical table for predicting the zwitterionic and diradical nature of addition and polymerization reactions of tetramethylenes. Here we attempted to extend this work to trimethalylenes by studying the thermal ring opening of ethyl chrysanthemate, ethyl 1-cyano-2-(4-methoxyphenyl)-cyclopropane-corboxylate, ethyl 1-cyano-2-(2-methoxyphenyl)-cyclopro-panecroboxylate, and diethyl 1,3-dicyano-w,r-di(2-methoxyphenyl)-cyclobutanedicarboxylate. These compounds were found to be thermally stable to 150°C and did not initiate polymerization in styrene, methyl methacrylate, a series of high boiling acrylates, and dimethyl fumarate. Free radicals were trapped in dimethyl fumarate to give oligomers at temperatures above 110°C. Even though the compounds studied did not initiate polymerization at decomposition temperatures of 175°-200°C, dimethyl fumarate may prove useful in these studies in the future.
32

Synthèse totale de trois produits naturels : la curacine A, la curacine B et la cystothiazole A

DeRoy, Patrick L. January 2003 (has links)
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
33

A study of the interaction of Zeise's dimer with cyclopropanes

Cheng, Sheng-San, 1952- January 2011 (has links)
Vita. / Digitized by Kansas Correctional Industries
34

Cobalt(II) catalysts - their use in the enantioselective ring-opening of 1,2-dioxines a thesis submitted for the degree of Doctor of Philosophy in the Faculty of Science

Jenkins, Natalie Faye. January 2003 (has links)
Includes Publications resultant of the thesis research Includes bibliographical references (leaves 180-196). Electronic publication; full text available in PDF format; abstract in HTML format. A series of new cobalt(II) ℓ-keto iminato complexes and cobalt(II) salens have been made and the effect of chirality in the northern, southern and peripheral quadrants of these catalysts, with respect to induced enantiomeric excess, during ring-opening of 1,2-dioxines has been determined. Electronic reproduction.[Australia] :Australian Digital Theses Program,2001. ix, 206 leaves : ill. ; 30 cm.
35

Nouveaux procédés d'électrosynthèse et de synthèse de cyclopropanes, d'époxydes et d'aziridines

Oudeyer, Sylvain Nedelec, Jean-Yves January 2007 (has links)
Thèse doctorat : Chimie : Paris 12 : 2003. / Version électronique uniquement consultable au sein de l'Université Paris 12 (Intranet). Titre provenant de l'écran-titre. Bibliogr. : 193 réf.
36

Calorimetric and structural studies of 1,2,3-trisubstituted cyclopropanes as conformationally constrained peptide mimics /

Davidson, James Prentice, January 2001 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references (leaves 270-290). Available also in a digital version from Dissertation Abstracts.
37

Studies on the Daphniphyllum alkaloids : strategies towards the synthesis of daphnicyclidin alkaloids

Harrington, Ryan Matthew, 1980- 21 September 2012 (has links)
Herein describes our approaches to the Daphniphyllum alkaloids. Specifically targeted are the recently isolated daphnicyclidins. The first chapter describes the structural diversity and biological properties of this class of alkaloids. Chapter 2 discusses some exploratory chemistry towards the daphnicyclidin fused tricycle. Chapter 3 describes the use of cyclopropanes in synthesis and their use in our ring expansion strategy. Preliminary results on the key cyclopropane ring expansion and the stereoselective quaternary center formation are also discussed. The chemistry concerning the diasteroselective cyclopropanation of a key intermediate and further details concerning the cyclopropane ring expansion are delineated. Chapter 4 contains the experimental details and characterization data for all new reported compounds. / text
38

Synthesis and evaluation of conformationally constrained peptide replacements and studies toward the total synthesis of kidamycin

Plake, Hilary Ruth 28 August 2008 (has links)
Not available / text
39

SYNTHESIS AND INITIAL BIOLOGICAL CHARACTERIZATION OF 10,11-METHYLENE-9- NONADECENE

Clark, James Reed, 1939- January 1971 (has links)
No description available.
40

The synthesis and acid-catalyzed rearrangement of the derivatives of 1-methyltricyclo[4400[superscript 2,6]]decan-3-one

Vora, Tushar Tribhuvandas 08 1900 (has links)
No description available.

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