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Dissertations / Theses on the topic 'Absolute configuration'

Author: Grafiati

Published: 4 June 2021

Last updated: 26 July 2025

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1

Perticarari, Sofia. "Atropisomeric xanthines: Synthesis, stereodynamics and absolute configuration." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amslaurea.unibo.it/9025/.

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During the thesis period a new class of atropisomeric xanthine derivatives has been studied. We decided to focus our attention on these purine bases because of their various biological activities, that could play an important role in the discovery of new bioactive atropisomers. The synthesized compounds bear an Aryl-N chiral axis in position 1 of the xanthine scaffold, around which the rotation is prevented by the presence of bulky ortho substituents. Through a retro synthetic analysis we synthesized three atropisomeric structures bearing in position 1 of the purine scaffold respectively an o-

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2

Marchesi, Chiara. "Conformational analysis and absolute configuration of Spiropyrazolones." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/13968/.

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The relative configuration of the four stereocenters of spiropyrazolones 1, epi-1 and 2 was determined by NMR-NOE analysis. It turned out that while compound 1 has the 1R*, 2S*, 3R*, 4S* relative configuration, epi-1 is the diastereoisomer at the C-4 (1R*, 2S*, 3R*, 4R* relative configuration). A full conformational analysis was performed by Molecular Mechanics (MMFF field) scan of the potential energy surface, and the best conformations were optimized by DFT calculations, including the effect of the solvent in the calculations. The absolute configuration of the three compounds was then deter

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3

Hoshi, Yuichiro. "Absolute anabelian cuspidalizations of configuration spaces of proper hyperbolic curves over finite fields." 京都大学 (Kyoto University), 2009. http://hdl.handle.net/2433/126568.

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Kyoto University (京都大学)<br>0048<br>新制・論文博士<br>博士(理学)<br>乙第12377号<br>論理博第1509号<br>新制||理||1507(附属図書館)<br>27312<br>UT51-2009-K686<br>京都大学大学院理学研究科数学・数理解析専攻<br>(主査)教授望月新一, 教授玉川安騎男, 教授向井茂<br>学位規則第4条第2項該当

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4

Romero, Adriano Lopes. "Contribuição ao conhecimento quimico do oleo-resina de copaiba : configuração absoluta de terpenos." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/249068.

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Orientador: Paulo Mitsuo Imamura<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica<br>Made available in DSpace on 2018-08-09T04:10:33Z (GMT). No. of bitstreams: 1 Romero_AdrianoLopes_M.pdf: 3449725 bytes, checksum: efe9788675287ceea4663671f084ad15 (MD5) Previous issue date: 2007<br>Resumo: óleo-resina de copaíba comercial é um exudado do tronco de diversas espécies do gênero Copaifera (Caesalpinoideae, Leguminosae). Esse óleo é utilizado na medicina popular como cicatrizante, antiinflamatório, no tratamento de bronquites e doenças de pele, assim como na ind

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5

Elsässer, Brigitta. "Investigation on structure-bioactivity relationship and determination of the absolute configuration of natural products." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=974404187.

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6

Pomini, Armando Mateus. "Acil-homosserina lactonas produzidas pelas bacterias fitopatogenicas Pantoea ananatis e Methylobacterium mesophilicum e defesa quimica no opilião Hoplobunus mexicanus." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/249296.

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Orientador: Anita Jocelyne Marsaioli<br>Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica<br>Made available in DSpace on 2018-08-13T13:06:45Z (GMT). No. of bitstreams: 1 Pomini_ArmandoMateus_D.pdf: 4501241 bytes, checksum: 249f7514962993874b22ddcad9831cc8 (MD5) Previous issue date: 2009<br>As bactérias Gram-positivas e Gram-negativas possuem um mecanismo de comunicação química intra-específico conhecido como ¿quorum-sensing¿, regulando a expressão de uma vasta gama de atividades biológicas. As bactérias Gram-negativas utilizam acil-homosserina lactonas (acil-HSLs) co

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7

Kato, Massuo Jorge. "A distribuição de lignóides e policetídeos nos frutos de Virola elongata (Benth.) Warb. (Myristicaceae)." Universidade de São Paulo, 1989. http://www.teses.usp.br/teses/disponiveis/46/46135/tde-02032011-154234/.

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Este trabalho descreve os isolamentos e as determinações estruturais dos metabólitos secundários das diferentes partes dos frutos (pericarpos, arilos, tegumentos e amêndoas) de Virola elongata. 0 material foi coletado em Humaitá (AM) e no Km 96 da Rodovia Santarém-Cuiabá (PA). Os constituíntes químicos foram isolados por cromatografias de adsorção e tiveram suas estruturas identificadas ou determinadas por técnicas espectrométricas usuais (IV, UV, RMN e EM). As configurações absolutas dos metabólitos foram deduzidas a partir de medidas espectropolarimétricas, ou auxiliadas pela obtenção de der

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8

Adams, Angela Dee. "Synthesis of guest molecules for studies of urea inclusion compounds." Thesis, Kansas State University, 2011. http://hdl.handle.net/2097/10724.

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Master of Science<br>Department of Chemistry<br>Mark D. Hollingsworth<br>Most urea inclusion compounds (UICs) are known to share a common packing arrangement in which the urea host forms helical ribbons held together by hydrogen bonds to form a series of linear, hexagonal tunnels. Because UICs can encapsulate a wide variety of linear guest molecules, they serve as useful model systems for probing mechanisms of crystal growth and molecular recognition. In this thesis, the syntheses (or attempts thereof) of six compounds that will serve as consequential guest molecules in studies of UICs are p

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9

Liu, Li. "Absolute Configuration and Biosynthesis of Pahayokolide A from Lyngbya sp. Strain 15-2 of the Florida Everglades." FIU Digital Commons, 2009. http://digitalcommons.fiu.edu/etd/134.

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Pahayokolides A-D are cytotoxic cyclic polypeptides produced by the freshwater cyanobacterium Lyngbya sp. strain 15-2 that possess an unusual β-amino acid, 3-amino-2,5,7,8-tetrahydroxy-10-methylundecanoic acid (Athmu). The absolute configuration of pahayokolides A-D was determined using advanced Marfey’s method. It was also confirmed that a pendant N-acetyl-N-methyl leucine moiety in pahayokolide A was absent in pahayokolides B and pahayokolides C-D were conformers of pahayokolide A. Feeding experiments indicated that the biosynthesis of the Athmu sidechain arises from leucine or α-ketoisovale

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10

Wai, Hung Tsang M. "The synthesis of chiral carboxylic acids and the determination of absolute configuration using [sup]1H NMR spectroscopy." Thesis, Kingston University, 1997. http://eprints.kingston.ac.uk/20611/.

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11

Higashiyama, Kazumi. "The semi-absolute anabelian geometry of geometrically pro-p arithmetic fundamental groups of associated low-dimensional configuration spaces." Kyoto University, 2019. http://hdl.handle.net/2433/242582.

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12

Husain, Philip Anwar. "Investigative enzymology of selected monooxygenases and development of (S)-N-Succinimidyl-a-Methoxyphenylacetate as a novel tool for assignment of absolute configuration." Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/27579.

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13

Sun, Han. "Stereochemistry of Challenging Natural Products Studied by NMR-based Methods." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2012. http://hdl.handle.net/11858/00-1735-0000-000D-FD1A-F.

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14

Romano, Angela. "Synthesis and characterization of new chiral molecules: 1,2,5,8-dithiadiazecine-6,7(5H,8H)-dione derivatives." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/13365/.

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The synthesis of ten-membered rings is not obvious. During this project, a new synthetic pathway was developed, which involves reaction of a benzothiazolium salt with a base and subsequent oxidation to air. The resulting ten-membered ring (1,2,5,8-dithiadiazecine-6,7(5H,8H)-dione 1) is inherently chiral because of constrained rotation about its interdependent stereogenic axes, and two enantiomers were detected and resolved by HPLC. The chiral properties of these enantiomers were studied by polarimetry, ECD spectrometry and X-ray and absolute configuration was assigned by DFT calculations. It w

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15

Mercanti, Elia. "Synthesis and dynamic study of atropisomeric compounds containing boron-carbon bond." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/10067/.

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In this thesis we studied the stereodynamic behavior of 1,2-azaborines variously substituted on boron (7a, 7b, 13). Depending on the hindrance of the asymmetric aryl substituent the resulting conformations could be stereolabile or configurationally stable. Through dynamic NMR and lineshape simulation, the energy rotational barriers of the different conformers are obtained. When the barrier is higher than 22-23 kcal/mol stable atropisomers that are fisically separable could be obtained (case of compound 13) and the free activation energy barrier is determinable by kinetic analysis. Absolute con

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16

Underwood, Brian Saxton. "Synthesis and determination of the absolute configuration of Armatol A through a polyepoxide cyclization cascade : revision of the proposed structures of Armatols A-F." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/62729.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2011.<br>Vita. Cataloged from PDF version of thesis.<br>Includes bibliographical references.<br>Cyclization Cascades Leading to the Tricyclic Fragment of Armatol A The synthesis of the fused 6,7,7-tricycle of armatol A was investigated. Fragments containing both a ketone and an aldehyde for subsequent fragment coupling were generated via a triepoxide cascade. Elimination of the secondary alcohol in the oxepane ring proved challenging; however, employing the Shapiro reaction successfully provided the desired oxepene. Ke

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17

Meyer, Luc. "Auxiliaires chiraux à centre d'aiguillage : nouveaux outils en synthèse asymétrique. Application à la synthèse d'α-aminoacides de configuration (R) ou (S)". Rouen, 1997. http://www.theses.fr/1997ROUES063.

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De nouveaux outils pour la synthèse asymétrique sont proposés : des auxiliaires chiraux à centre d'aiguillage (R,S). Le passage du (1R,2S,5R)-2-diméthylphénylméthyl-5-méthylcyclohexyl carbaldéhyde à l'imine correspondante du glycinate de méthyle, suivi de la déprotonation (diisopropylamidure de lithium), puis de l'alkylation par des halogénures d'alkyles conduit après hydrolyse à des α-aminoacides de configuration (R) avec des e. E. >98%. Il a été montré que pour obtenir les α-aminoacides de configuration (S), il n'était pas nécessaire d'inverser la totalité des centres stéréogéniques de l'ald

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18

Miquet, Stéphanie. "Synthèse énantiosélective de terpènes naturels : kopéoline, kopéolone et siphonellinol D." Thesis, Aix-Marseille, 2014. http://www.theses.fr/2014AIXM4343.

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Ce travail développe différentes stratégies pour la synthèse énantiosélective de sesquiterpènes naturels à partir de chirons obtenus par biocatalyse. La première partie est consacrée aux premières synthèses énantiosélectives de la kopéoline, et de la kopéolone. La synthèse de la structure décrite de la kopéoline est réalisée, les composés ont été entièrement caractérisés. Les résultats montrent que les structures reportées n'ont pas été correctement assignées, et suggèrent une mauvaise attribution des stéréocentres au cours de l'isolement des produits naturels. Ainsi, deux nouvelles structures

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19

Miquet, Stéphanie. "Synthèse énantiosélective de terpènes naturels : kopéoline, kopéolone et siphonellinol D." Electronic Thesis or Diss., Aix-Marseille, 2014. http://www.theses.fr/2014AIXM4343.

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Ce travail développe différentes stratégies pour la synthèse énantiosélective de sesquiterpènes naturels à partir de chirons obtenus par biocatalyse. La première partie est consacrée aux premières synthèses énantiosélectives de la kopéoline, et de la kopéolone. La synthèse de la structure décrite de la kopéoline est réalisée, les composés ont été entièrement caractérisés. Les résultats montrent que les structures reportées n'ont pas été correctement assignées, et suggèrent une mauvaise attribution des stéréocentres au cours de l'isolement des produits naturels. Ainsi, deux nouvelles structures

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20

Schmidt, Manuel. "Synthese chiraler Alignmentmedien zur Enantiomerenunterscheidung via anisotroper NMR-Parameter & Bestimmung der absoluten Konfiguration von (–)-erythro-Mefloquin HCl." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2013. http://hdl.handle.net/11858/00-1735-0000-0022-5F4D-E.

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Im Rahmen dieses Promotionsprojektes wurde ein neues, chirales Orientierungsmedium zur Enantiomerenunterscheidung chiraler Amine vorgestellt. Ausgehend von dem enantiomerenreinen (R)- oder (S)-konfigurierten beta-Aminoalkohol, wurde in einer fünfstufigen Synthese (R)- respektive (S)-2-Acrylamido-2-phenylethansulfonsäure ((R)- / (S)-APhES), das zugrundeliegende chirale Monomer dieses neuen Polymergel-basierten Orientierungsmediums, hergestellt. Die daraus resultierenden chiralen Polymergele sind somit in beiden enantiomeren Formen zugänglich. Während die bisher existenten chiralen Orientierungs

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21

Escudero, Adán Eduardo Carmelo. "High resolution X-ray single crystal diffraction." Doctoral thesis, Universitat Rovira i Virgili, 2018. http://hdl.handle.net/10803/586278.

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Aquesta tesi doctoral descriu l'ús de dades d'alta resolució de difracció de raigs X de monocristall per a la obtenció de mapes experimentals detallats de distribució de densitat de càrrega. Aquests mapes serveixen per evidenciar experimentalment l'existència d'interaccions intra- i inter-moleculars febles dins de l'estructura del vidre. Els mapes de densitat de càrrega s'obtenen mitjançant un refinament multipolar de l'estructura cristal·lina. En concret, aquest treball se centra en evidenciar experimentalment les interaccions atractives no covalent recentment descrites teòricament i que

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22

Cedrón, Juan Carlos. "Métodos para determinar la configuración absoluta de una molécula." Revista de Química, 2012. http://repositorio.pucp.edu.pe/index/handle/123456789/99434.

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Determinar la configuración absoluta de las moléculas quirales representa un gran reto para los químicos orgánicos. Para conseguir este objetivo existen diversas técnicas, las cuales se describen en el presente trabajo, así como ejemplos de cómo han sido utilizadas para la determinación de la configuración absoluta de productos naturales.<br>Methods for the assignment of the absolute configuration of an organic molecule: The assignment of the absolute configuration of chiral molecules represents a great challenge for organic chemists. There are several techniques in order to establish it, and

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23

Gruner, Konstanze K., Thomas Hopfmann, Kazuhiro Matsumoto, Anne Jäger, Tsutomu Katsuki, and Hans-Joachim Knölker. "Efficient iron-mediated approach to pyrano[3,2-a]carbazole alkaloids - first total syntheses of O-methylmurrayamine A and 7-methoxymurrayacine, first asymmetric synthesis and assignment of the absolute configuration of (−)-trans-dihydroxygirinimbine." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-138748.

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Iron-mediated oxidative cyclisation provides an efficient approach to pyrano[3,2-a]carbazole alkaloids. Thus, improved routes to girinimbine and murrayacine as well as the first total syntheses of O-methylmurrayamine A and 7-methoxymurrayacine are reported. Asymmetric epoxidation of girinimbine led to (−)-trans-dihydroxygirinimbine and the assignment of its absolute configuration<br>Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich

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24

Gruner, Konstanze K., Thomas Hopfmann, Kazuhiro Matsumoto, Anne Jäger, Tsutomu Katsuki, and Hans-Joachim Knölker. "Efficient iron-mediated approach to pyrano[3,2-a]carbazole alkaloids - first total syntheses of O-methylmurrayamine A and 7-methoxymurrayacine, first asymmetric synthesis and assignment of the absolute configuration of (−)-trans-dihydroxygirinimbine." Royal Society of Chemistry, 2011. https://tud.qucosa.de/id/qucosa%3A27777.

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Iron-mediated oxidative cyclisation provides an efficient approach to pyrano[3,2-a]carbazole alkaloids. Thus, improved routes to girinimbine and murrayacine as well as the first total syntheses of O-methylmurrayamine A and 7-methoxymurrayacine are reported. Asymmetric epoxidation of girinimbine led to (−)-trans-dihydroxygirinimbine and the assignment of its absolute configuration.<br>Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

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25

Braconnier, Marie-France. "L'harmonine alcaloïde défensif de Coccinellidae. Etude structurale. Configuration absolue - Synthèse totale." Doctoral thesis, Universite Libre de Bruxelles, 1986. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/213534.

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26

Leclercq, Sabine. "Les alcaloides défensifs de fourmis du genre Solenopsis: configuration absolue et biosynthèse." Doctoral thesis, Universite Libre de Bruxelles, 1996. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/212361.

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27

Thirionet, Isabelle. "Les alcaloïdes défensifs de fourmis du genre solenopsis :synthèse asymétrique et configuration absolue." Doctoral thesis, Universite Libre de Bruxelles, 1993. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/212788.

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28

Merlin, Patrick. "Les alcaloïdes défensifs de la fourmi Tetraponera Sp. Synthèse stéréosélective, configuration absolue et biosynthèse." Doctoral thesis, Universite Libre de Bruxelles, 1990. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/213152.

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29

Börger, Carsten, Micha P. Krahl, Margit Gruner, Olga Kataeva, and Hans-Joachim Knölker. "First total synthesis of the biscarbazole alkaloid oxydimurrayafoline." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-139201.

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We report the first total synthesis of oxydimurrayafoline via nucleophilic substitution at the benzylic position at C-3 of the carbazole framework<br>Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich

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30

Katele, Zongwe Felix. "Chemical profiling of cultivated and wild African ginger and absolute configurations of compounds from mangroves and Ancistrocladus species." Diss., University of Pretoria, 2015. http://hdl.handle.net/2263/53504.

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Medicinal plants and natural products have played a pivotal role as a source of drug leads that has led to improving health conditions and have provided humankind with numerous pharmacologically active drugs. Other than the biological screening and chemical profiling of plant extracts, the isolation, purification and elucidation of the full absolute structures of natural compounds are some of the key areas required in the time-consuming process of drug discovery based on natural products. Elucidation of the absolute configuration (AC) of chiral natural products represents one of the most

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31

Macours, Pascale. "Synthèse asymétrique et détermination de la configuration absolue de tétraponérines, alcaloïdes défensifs de la fourmi tétraponera sp." Doctoral thesis, Universite Libre de Bruxelles, 1995. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/212610.

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32

Crassous, Jeanne. "Synthèse des énantiomères du bromochlorofluorométhane et détermination de leur configuration absolue par modélisation moléculaire et activité optique Raman." Lyon, École normale supérieure (sciences), 1996. http://www.theses.fr/1996ENSL0036.

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Les enantiomeres (+) et (-) du bromochlorofluoromethane (chfclbr) ont ete synthetises par decarboxylation des enantiomeres de meme signe de l'acide bromochlorofluoroacetique (brclfcco#2h). Cet acide a lui meme ete dedouble par cristallisation de ses sels diastereoisomeres avec la strychnine, et sa configuration absolue s-(+) a ete etablie par rayons x. Puis la question de la configuration absolue de chfclbr a ete etudiee a l'aide des spectres d'activite optique raman (theoriques et experimentaux) et par modelisation moleculaire. La configuration absolue s-(+) de cet haloforme a ainsi ete etabl

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33

Börger, Carsten, Micha P. Krahl, Margit Gruner, Olga Kataeva, and Hans-Joachim Knölker. "First total synthesis of the biscarbazole alkaloid oxydimurrayafoline." Royal Society of Chemistry, 2012. https://tud.qucosa.de/id/qucosa%3A27812.

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We report the first total synthesis of oxydimurrayafoline via nucleophilic substitution at the benzylic position at C-3 of the carbazole framework.<br>Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

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SILVA, ALEXANDRE F. P. da. "Calibração da potência do reator IPEN/MB-01 na configuração cilíndrica de menor excesso de reatividade obtida a partir da medida absoluta do fluxo médio de nêutrons." reponame:Repositório Institucional do IPEN, 2014. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11792.

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Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2014-11-10T10:53:10Z No. of bitstreams: 0<br>Made available in DSpace on 2014-11-10T10:53:10Z (GMT). No. of bitstreams: 0<br>Dissertação (Mestrado em Tecnologia Nuclear)<br>IPEN/D<br>Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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Faghih, Ramine. "Synthèse d'azido-sucres fluores et d'hydrates de carbone branchés : détermination de la configuration absolue d'alcools secondaires chiraux : structure de la virustomycine-A." Paris 11, 1985. http://www.theses.fr/1985PA112021.

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Nous présentons dans le premier chapitre de cette thèse la préparation d’azido-fluoro-sucres précurseurs d’acides α-aminés β-fluorés et d’acides β-aminés α-fluorés. Dans le deuxième chapitre nous rapportons la synthèse d’un composé apparenté à la daunomycine. Le troisième chapitre traite de la synthèse de sucres branchés et d’une tentative d’introduction stéréospécifique d’un centre asymétrique en C-6 des hydrates de carbone. Les deux derniers chapitres de cette thèse sont consacrés à l’application de la R. M. N. à deux problèmes différents : - nous proposons une nouvelle méthode de déterminat

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Khudr, Hussein. "Applications en chimie structurale de la résonnance magnétique nucléaire dans les milieux orientés chiraux." Paris 11, 2008. http://www.theses.fr/2008PA112052.

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La RMN dans les milieux orientés chiraux est actuellement la technique d'analyse des molécules chirales la plus générale. Dans ces phases cristallliquides deux énantiomères s'orientent différemment sous l'effet des interactions entre les molécules chirales et les fibres polypeptidiques. Par conséquent toutes les interactions magnétiques sensibles à l'ordre sont différentes pour deux énantiomères. Dans une première partie, nous avons synthétisé les quatre isomères de chiralité isotopique du [1-2Hl]-glycérol avec d'excellentes puretés énantiomériques. Nous avons mis au point une méthode analytiq

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37

Ziani, Latifa. "Développement de diverses méthodologies RMN en milieu cristal liquide chiral." Paris 11, 2008. http://www.theses.fr/2008PA112036.

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Le travail de cette thèse porte sur des développements de la RMN en milieu cristal liquide chiral. Dans un premier temps, de nouvelles méthodologies RMN 2D en milieu cristal liquide chiral ont été développées afin de simplifier l’analyse spectrale des spectres proton et carbone-13 permettant de mesurer simplement des couplages dipolaires et de visualiser la différenciation énantiomérique. Ensuite, nous avons étudié l’effet de la température, du champ magnétique, du degré de polymérisation et de la concentration en polymère sur la différenciation énantiomérique. Nous avons montré que ces paramè

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38

Dutot, Laurence. "Architectures β-peptidiques hélicoïdales de dérivés éthers couronnes du résidu (S)-β[puissance 3]-HDOPA : chiralité axiale induite du noyau biphényle : une nouvelle méthode d'attribution de configuration absolue d'α- et β-amino acides". Versailles-St Quentin en Yvelines, 2006. http://www.theses.fr/2006VERS0028.

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Les β-peptides, du fait de leur grande capacité à résister aux dégradations enzymatiques et à adopter des structures secondaires stables et variées, font l'objet d'un intérêt grandissant. Dans cette optique, un nouveau résidu β-amino acide dérivé du (L)-DOPA, (S)-β3-HDOPA, a été synthétisé. Des chaînes β-peptidiques incorporant des résidus porteurs d'éthers couronnes dérivés du (S)-β3-HDOPA associés à des résidus (1S,2S)-ACHC inducteurs d'hélice 314, ont été préparées et analysées par RMN 1H, dichroïsme circulaire (DC) et FT/IR afin de déterminer leur structure secondaire. Par ailleurs, le tra

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39

Köppen, Robert. "Hexabromcyclododecan in Biota." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2008. http://dx.doi.org/10.18452/15787.

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Ziel dieser Arbeit war es, ein enantiomerenspezifisches Analysenverfahren für die Bestimmung von Hexabromcyclododecan (HBCD) in Biota-Proben zu entwickeln und die bei erhöhten Temperaturen auftretende Isomerisierung der HBCD-Stereoisomere zu untersuchen. Als erstes wurden die sechs HBCD-Enantiomere isoliert, mittels Einkristallstrukturanalyse, NMR- und IR-Spektroskopie charakterisiert und erstmals die spezifischen Drehwinkel der reinen Enantiomere mit den absoluten Konfigurationen und der Elutionsreihenfolge auf einer chiralen beta-PM-Cyclodextrin-Phase korreliert. Die Untersuchungen der HBC

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40

Srikirin, Yupayao. "Partial absolute configuration of the antibiotic nystatin." Phd thesis, 1986. http://hdl.handle.net/1885/138911.

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41

Tennant, Shaun. "Chiral biaryls : the absolute configuration of streptonigrin." Phd thesis, 1992. http://hdl.handle.net/1885/140167.

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42

Maksimenka, Katsiaryna (Katja). "Absolute Configuration by Circular Dichroism: Quantum Chemical CD Calculations." Doctoral thesis, 2010. https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-56552.

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Quantum chemical calculations of circular dichroism (CD) spectra in combination with experimental CD studies are one of the most efficient analytical tools for the elucidation of the three-dimensional structure of a chiral molecule. In the present work 18 chiral compounds of most different molecular structures and origins were investigated using various theoretical methods (the semiempirical CIS methods, the time-dependent DFT and DFT/MRCI approaches). The advantages and limitations of the applied methods were discussed in the context of the studied compounds. Furthermore, the last part of thi

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43

Yong, Shyh-Parn, and 楊士磐. "Studies on the Resolution and Absolute Configuration of cis-2- Phenylcycloheptanol." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/00821715541970085652.

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碩士<br>高雄醫學院<br>藥學研究所<br>84<br>The N-carbobenzoxy-L-phenylalanine (N-CBZ-L-Phe) and N- carbobenzoxy-D-phenylalanine (N-CBZ-D-Phe) were applied to the optical resolution of (±)-cis-2-phenylcycloheptanol. The resolution of (+)- and (-)-diastereomeric esters was obtained with high optical purity (>98 % e.e.) by simplerecrystallization. The target esters were hydrolysis to (-)-cis-2-phenyl-cycloheptanol with [α] -93.7 and (+)-cis-2- phenylcycloheptanol with [α] +94.4. The absolute

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44

Maksimenka, Katsiaryna [Verfasser]. "Absolute configuration by circular dichroism : quantum chemical CD calculations / vorgelegt von Katja Maksimenka." 2010. http://d-nb.info/1012765938/34.

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45

Zlatopolski, Boris. "Final Elucidation of the Absolute Configuration of Hormaomycin - Total Synthesis of Hormaomycin and Analogs." Doctoral thesis, 2003. http://hdl.handle.net/11858/00-1735-0000-0006-B0AE-2.

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46

Elsässer, Brigitta [Verfasser]. "Investigation on structure-bioactivity relationship and determination of the absolute configuration of natural products / von Brigitta Elsässer." 2004. http://d-nb.info/974404187/34.

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47

Zlatopolski, Boris [Verfasser]. "Final elucidation of the absolute configuration of hormaomycin : total synthesis of hormaomycin and analogs / vorgelegt von Boris Zlatopolski." 2004. http://d-nb.info/972653597/34.

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48

Fraley, Mark E. "Synthesis of (+)-dynemicin A and analogs of wide structural variability. Establishment of the absolute configuration of natural dynemicin A." Thesis, 1995. https://thesis.library.caltech.edu/3870/1/Fraley_me_1995.pdf.

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A highly convergent synthetic route to the potent natural antitumor agent (+)-dynemicin A (1) is described. Key features of the synthesis include: (1) the condensation of the potassium enolate of menthyl acetoacetate with trans-ethyl crotonate, providing the optically pure trans-disubstituted 1,3-cyclohexanedione 38; (2) the palladium-catalyzed coupling of the enol triflate 37 with t-butyl 2-borono-4-methoxycarbanilate to furnish 35, followed by the thermolysis of the latter to afford the quinolone 34; (3) the stereoselective acetylide addition of the (Z)-enediyne bridge to an acylquinolinium

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49

Gutala, Phaneendra. "Enantiospecific Total Synthesis of Phomopsolide B, Macrosphelides A & E and Total Synthesis & Determination of Absolute Configuration of Synargentolide B." Thesis, 2013. http://etd.iisc.ac.in/handle/2005/3302.

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Section I of the thesis deals with the enantiospecific total synthesis of phomopsolide B. Phomopsolide B was isolated from a strain of Phomopsis Oblonga. Enantiospecific total synthesis of phomopsolide B was accomplished in 13 overall yield in 12 linear steps using (S)-lactic acid and L-tartaric acid as chiral pool precursors. Present approach involves the efficient use of -keto phosphonate derived from commercially available (S)-ethyl lactate. Horner-Wadsworth-Emmons reaction and Still-Gennari olefination were employed as key reactions in the synthesis (scheme 1). Scheme 1: Total synthesis

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50

Gutala, Phaneendra. "Enantiospecific Total Synthesis of Phomopsolide B, Macrosphelides A & E and Total Synthesis & Determination of Absolute Configuration of Synargentolide B." Thesis, 2013. http://etd.iisc.ernet.in/2005/3302.

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Section I of the thesis deals with the enantiospecific total synthesis of phomopsolide B. Phomopsolide B was isolated from a strain of Phomopsis Oblonga. Enantiospecific total synthesis of phomopsolide B was accomplished in 13 overall yield in 12 linear steps using (S)-lactic acid and L-tartaric acid as chiral pool precursors. Present approach involves the efficient use of -keto phosphonate derived from commercially available (S)-ethyl lactate. Horner-Wadsworth-Emmons reaction and Still-Gennari olefination were employed as key reactions in the synthesis (scheme 1). Scheme 1: Total synthesis

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