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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.
1

Synthetic approaches to the asymmetric synthesis of #alpha#-keto and #beta#-hydroxy esters

Milsom, Greig January 1999 (has links)
No description available.
2

Biosynthesis of fungal polyketides : compactin and 6-methylsalicylic acid

Oldfield, Mark F. January 1995 (has links)
No description available.
3

Diastereoselective reactions of atropisomeric lactams

Walker, Matthew David January 2000 (has links)
No description available.
4

New reagents in asymmetric synthesis and studies on the Heck reaction

Fergus, Julie Anne January 1998 (has links)
No description available.
5

Toward Macromolecular Shape And Size Control: Novel Enantioselective Nitrations And Iterative Exponential Growth Methods For Polymer Synthesis

Campbell, Joseph Patrick 01 January 2019 (has links)
Chirality is a key principle in organic chemistry. All chiral compounds are non-superimposable mirror images of each other and therefore lack an improper axis of rotation (Sn). These mirror images often have identical properties in an achiral environment, however when two chiral molecules interact, they produce different shapes and properties. Nature, to this extent takes advantage of this aspect through unique formation of shape defined biological macromolecules that are tailored to carry out various life processes. This level of shape control is only made possible because of natural chiral monomers such as amino acids or glycosides that make up such macromolecules. Under new methods such as Chirality Assisted Synthesis (CAS), shape and size-controlled polymers and macromolecules can be realized through the use of chiral monomers to make well defined macromolecules. Because chirality dictates shape, and shape defines function in reference to macromolecules, controlling the chirality of monomers, while concurrently dictating shape and size can lead to the potential of biomimetic methodologies and cage like structures. Accessing shape defined monomers can be difficult especially when in reference to chiral compounds. The unique structure of enantiopure tribenzotriquinacenes show promise in the formation of well-defined cage like structures through utilization of CAS methodology. Synthesis of functionalized tribenzotriquinacenes along with development of an enantioselective electrophilic aromatic nitration method was attempted. Further exploration into the effectiveness of through-space enantioselective nitrations found a dependence on solvent temperature, and the auxiliary that is used. Synthetic difficulties, results, modifications and processes toward a generalized method are presented herein. In addition, controlling the size of polymers has always been a difficult synthetic challenge. Overall selectivity toward one product over another is determined via a variety of chemical properties. However, the formation of sequence and size defined polymers are a prominent aspect of natural polymers. The size selective synthesis, of unique ABAB sequenced polymers was attempted using an iterative exponential growth method. The ability to scale up these processes and create monodisperse oligoethers is also presented and described herein.
6

Bile Acid-Based Chiral Auxiliaries In Asymmetric Synthesis

Bandyopadhyaya, Achintya K 12 1900 (has links) (PDF)
No description available.
7

Synthesis of original fluorinated cyclopropylcarboxylates

Ivashkin, Pavel 22 November 2013 (has links) (PDF)
Organofluorine compounds constitute a large part of all the drugs, crop protection agents and advanced materials produced nowadays. Therefore, there is a great interest in developing the new methods of synthesis of organofluorine compounds. In this thesis we report a novel method of synthesis of monofluorinated cyclopropanes based on the Michael-initiating ring closure (MIRC) reaction. Our method allows obtaining polysubstituted monofluorinated cyclopropanes from ethyl dibromofluoroacetate and various Michael acceptors. We have also implemented the asymetric version of cyclopropanation using a novel oxazolodinone-derived chiral fluorinated reagent. In the final part of this thesis we report the synthesis of a fluorinated analog of L-FAP4, a potent agonist of group II metabotropic glutamate receptors (mGluR II). Incorporation of a fluorine atom is expected to increase the biological activity and bioavailabiblity of this compound.
8

Adição de nucleofilos a ions N-aciliminios quirais e reações de ciclização promovidas por Pd(0) / Nucleophilic addition to chiral N-acyliminium ions and palladium(0)-mediated cyclization reactions

Robello, Luis Gustavo, 1975- 14 December 2006 (has links)
Orientador: Ronaldo Aloise Pilli / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-08T04:04:52Z (GMT). No. of bitstreams: 1 Robello_LuisGustavo_D.pdf: 7203530 bytes, checksum: a92a57231d7587b04ebb16da51b52419 (MD5) Previous issue date: 2006 / Doutorado / Quimica Organica / Doutor em Ciências
9

Synthesis of original fluorinated cyclopropylcarboxylates / Synthèse des cyclopropylcarboxylates fluorés originaux

Ivashkin, Pavel 22 November 2013 (has links)
Les composés organofluorés constituent une grande partie de produits pharmaceutiques, ainsi que pesticides, herbicides et matériaux fabriqués actuellement. Développement des méthodes sélectives de la synthèse des composés organofluorés est donc d'intérêt principal pour la chimie. Dans cette thèse, nous décrivons la nouvelle méthode de synthèse des cyclopropanes monofluorés basé sur la cyclisation initiée par la réaction de Michaël (MIRC). Notre méthode permet d'obtenir les cyclopropanes monofluorés polysubstitués à partir de dibromofluorocetate d'éthyle et différents accpteurs de Michaël. Nous avons aussi réalisé la cyclopropanation asymétrique en utilisant le nouveau réactif fluoré chiral à base d'oxazolidinone. Dans la partie finale de cette thèse nous décrivons la synthèse de l'analogue fluoré de L-FAP4, l'agoniste puissant des récepteurs métabotropiques de glutamate groupe II(mGluR II), afin d'augmenter l'activité biologique et la biodisponibilité de ce composé. / Organofluorine compounds constitute a large part of all the drugs, crop protection agents and advanced materials produced nowadays. Therefore, there is a great interest in developing the new methods of synthesis of organofluorine compounds. In this thesis we report a novel method of synthesis of monofluorinated cyclopropanes based on the Michael-initiating ring closure (MIRC) reaction. Our method allows obtaining polysubstituted monofluorinated cyclopropanes from ethyl dibromofluoroacetate and various Michael acceptors. We have also implemented the asymetric version of cyclopropanation using a novel oxazolodinone-derived chiral fluorinated reagent. In the final part of this thesis we report the synthesis of a fluorinated analog of L-FAP4, a potent agonist of group II metabotropic glutamate receptors (mGluR II). Incorporation of a fluorine atom is expected to increase the biological activity and bioavailabiblity of this compound.

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