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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.
51

Methylene addition to some 7-norbornadienyl derivatives

Haywood-Farmer, John S. January 1965 (has links)
The synthesis of exo-antl-tricyclo [3,2,1,02,4] octan-8-ol (V) and exo-anti-8-methoxy-tricyclo [3,2,1,02,4] octane (VI) was carried out by the cuprous chloride catalysed reaction of diazoraethane with anti-7-norbornenol (IV). The methyl ether (VI) was previously thought to be the endo isomer of (V). Methylene addition to the syn double bond of 7-norbornadienyl acetate (III) was accomplished using the above method to give a 5 to 1 mixture of exo-syn-tricyclo [3,2,1,02,4] oct-6-ene-8- acetate (VII) and endo-syn-tricyclo [3,2,1,02,4] oct-6-ene-8- acetate (VIII). These two acetates were inseparable but the corresponding alcohols exo-syn-tricyclo [3,2,1,02,4] oct-6-ene-8-ol (X) and endo-syn-tricyclo [3,2,1,02,4] oct-6-ene-8-ol (XI), formed by reduction of the acetate mixture with lithium aluminum hydride, could be separated by gas-liquid partition chromatography. The stereochemistry of these two products was determined by the multiplicity and by the chemical shift of the olefinic proton signals in their proton nuclear magnetic resonance spectra. Catalytic reduction of these two alcohols gave exo-syn-tricyclo [3,2,1,02,4] octan-8-ol (XIII) and endo-syn-trlcyclo [3,2,1,02,4] octan-8-ol (XIV). From the diazomethane-7-norbornadienyl acetate reaction a diadduct acetate, tetracyclo [3,3,1,02,4,06,8]nonan-9-acetate (IX), was also obtained which reduced to the alcohol tetracyclo [3,3,1,02,4,06,8] nonan-9-ol (XII). The stereochemistry of these diadducts was not determined. Acetolysis studies on the p-bromobenzene- sulfonyl (brosylate) derivative of exo-anti-tricyclo [3,2,1,02,4]octan-8-ol (V) at 200° indicate that the reaction proceeds by formation of a carbonium ion at C8, which then rearranges, destroying the cyclopropyl group. Although unchanged (V) could be obtained by lithium aluminum hydride reduction of about 80% solvolysed brosylate at 200°, none of the products of complete solvolysis could be identified. / Science, Faculty of / Chemistry, Department of / Graduate
52

Étude mécanistique sur la formation de thiazolines via l'activation d'amides. Application de l'oléfination de S. Julia à la préparation de diènes. Élaboration vers la synthèse de la curacine A

Berthelette, Carl January 1999 (has links)
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
53

Studies Related to the Synthesis of Chroman- And Quinoline-Based Heterocycles

Stokes, Sean L Robert 15 December 2012 (has links)
Chromans and quinolines can be found in the core structures of many biologically active natural products. Recognizing new and efficient ways to synthesize these useful compounds is vital to modern drug design. Calyxin I, Calyxin J and Epicalyxin J are three natural products that have been shown to have antiproliferative activity against two cancer cell lines. The core tetrahydropyranochromene ring system that is common among all three compounds was synthesized. The preferred diastereomer in this synthesis was the syn conformer, which was confirmed by a 2-D NOESY experiment. Theoretical MP2 calculations showed that a favorable pi-pi stacking interaction could be responsible for the diastereoselectivity. A two-step synthesis of tetrahydro-2Hurochromenones was achieved. This synthesis involved the cyclopropanation of 2H-chromenes using diazo compounds or iodonium ylides and a rhodium catalyst. In the presence of a Lewis acid, the cyclopropane intermediate underwent acid-catalyzed rearrangement to a gamma-lactone. The stereochemistry of the lactones was based on X-ray crystallography. Lactonization of 2H-chromenes could be important in the construction of larger flavonoids or biflavonoids in the future. 4-Arylquinolines and 2,4-diarylquinolines were produced using a [4+2] cycloaddition reaction as the key step in their synthesis. An array of N-aryl and N-protected 1-azadienes were constructed from their corresponding cinnamaldehydes or chalcones. A 1,4-dihydroquinoline cycloadduct was prepared from a [4+2] cycloaddition reaction of a 1-azadiene with benzyne. Among the N-protected cycloadducts, the N-tosyl derivatives were used to generate various quinolines. Also, a short synthesis of 3-O-methylviridicatin from one of the N-tosyl cycloadducts is presented.
54

I. Studies of synthesis of phenanthreno [9,10-2',3']cyclopropenes. II. The chemistry of substituted nitrocyclobutanes /

Ranganathan, Subramania January 1962 (has links)
No description available.
55

Approaches to 9,10-phenanthrocyclopropenyl systems /

Roberts, T. D. January 1967 (has links)
No description available.
56

Reactions of halocyclopropanes /

Houser, Charles W. January 1968 (has links)
No description available.
57

Kinetics and mechanism of phenylcyclopropane cleavage with palladium(II) chloride /

Levin, Charles January 1970 (has links)
No description available.
58

Conjugative and homoconjugative interactions of cyclopropane rings in neutral and cationic systems /

Detty, Michael Ray January 1977 (has links)
No description available.
59

Synthesis of precursors of a highly pyramidalized alkene and ab initio calculations on methylenecyclopropane, cyclopropene, and 1,3-diradicals /

Johnson, William T. G. January 1999 (has links)
Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (leaves 84-88).
60

Reactions of alkenes with nitrogen containing reagents

Hewlins, Stuart A. January 1995 (has links)
No description available.

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