Dissertations / Theses on the topic 'Polypropionates'
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Megevand, Sophie. "Etudes sur la synthèse de fragments polypropionates /." [S.l.] : [s.n.], 2000. http://library.epfl.ch/theses/?nr=2271.
Full textCurrie, Russell. "Studies on the total synthesis of non-contiguous polypropionates." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608263.
Full textFranklin, A. S. "Studies towards the total synthesis of marine derived polypropionates." Thesis, University of Cambridge, 1995. https://www.repository.cam.ac.uk/handle/1810/272999.
Full textKernen, Philippe. "Sucres nus de la 2e génération : synthons homochiraux pour les polypropionates /." [S.l.] : [s.n.], 1994. http://library.epfl.ch/theses/?nr=1265.
Full textRuiz, Johal. "Nouvelles synthèses par catalyse de composés organosilicés et leur transformation en fragments de polycétides." Thesis, Rennes 1, 2015. http://www.theses.fr/2015REN1S138/document.
Full textThe aldol reactions is one of the most important and commonly used methods to form C-C bonds. The catalytic tandem isomerization-aldol reaction of allylic alcohols allows to perform this reaction with many synthetic advantages. Thus, we have prepared by this method beta-hydroxyacylsilanes from alpha-hydroxyallylsilanes. First, we have attempted to develop a catalytic asymmetric version of this reaction, and also to synthesize beta-hydroxyacylsilanes by direct aldol reaction. Then, we used alpha-hydroxyallylsilanes to prepare alpha-silyl aldols trough epoxidation reactions. Next, we synthesized aldols from protected beta-hydroxyacylsilanes in a simple and efficient fashion which allowed us to perform iterative aldol reactions. We have illustrated the potential of this method by the synthesis of a fragment of (±)-pironetine. Finally, we have synthesized, from the same protected beta-hydroxyacylsilanes, silyl enol ethers that next have been used successfully as substrates for Mukaiyama aldol reactions
Jeffery, David William, and david jeffery@awri com au. "Total Synthesis of the Putative Structure of Tridachiahydropyrone." Flinders University. Chemistry, Physics and Earth Science, 2005. http://catalogue.flinders.edu.au./local/adt/public/adt-SFU20050603.095257.
Full textLe, Roux Rémi. "Synthèse biomimétique de motifs polypropionates par hydrogénation asymétrique à l'aide de complexes chiraux du ruthénium. Application aux synthèses du Dolabélide A et du (+)-Discodermolide." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2007. http://pastel.archives-ouvertes.fr/pastel-00003946.
Full textLe, Roux Rémi. "Synthèse biomimétique de motifs polypropionates par hydrogénation asymétrique à l'aide de complexes chiraux du ruthénium : application aux synthèses du dolabelide A et du (+)-discodermolide." Paris 6, 2007. https://pastel.archives-ouvertes.fr/pastel-00003946.
Full textRoche, Christophe. "Approches synthétiques du (+)-discodermolide et du dolabélide A par hydrogénation asymétrique à l'aide de complexes chiraux de ruthénium." Phd thesis, Paris 6, 2008. http://pastel.archives-ouvertes.fr/pastel-00004977.
Full textChannon, J. A. "A general aldol approach to polypropionate synthesis." Thesis, University of Cambridge, 1992. https://www.repository.cam.ac.uk/handle/1810/272244.
Full textKasprzyk, Milena, and milena kasprzyk@freehills com. "Synthetic Studies Towards the Tridachione Family of Marine Natural Products." Flinders University. Chemistry, Physics and Earth Sciences, 2008. http://catalogue.flinders.edu.au./local/adt/public/adt-SFU20081107.085933.
Full textChapman, Robert. "Sustainable methodology for the synthesis of amides, esters and polypropionate fragments." Thesis, University of Bath, 2017. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.715298.
Full textEl, Baz Yana [Verfasser]. "Polypropionate und Borrelidin: Vielseitige Anwendung der Bürzeldrüsensekrete von Wasservögeln / Yana El Baz." München : Verlag Dr. Hut, 2010. http://d-nb.info/1009095269/34.
Full textFerret, Haidy. "Obtention de motifs desoxy-polypropionate application à la synthèse de composés biologiquement actifs." Paris 6, 2009. http://www.theses.fr/2009PA066168.
Full textDefosseux, Magali. "Ouvertures électrophiles de cyclopropylcarbinols : synthèse totale de la zincophorine." Paris 6, 2004. http://www.theses.fr/2004PA066079.
Full textLister, Troy, and mike perkins@flinders edu au. "Total Synthesis of Auripyrone A and Related Metabolites." Flinders University. School of Chemistry, Physics and Earth Sciences, 2006. http://catalogue.flinders.edu.au./local/adt/public/adt-SFU20060804.125858.
Full textEustache, Florence. "Réductions énantiocatalytiques de composés dicarbonyles : application à la synthèse du fragment C14-C25 de la bafilomycine A1." Paris 6, 2002. http://www.theses.fr/2002PA066127.
Full textJacolot, Maïwenn. "Vers la synthèse totale du portentol et de la stachybotrine C." Thesis, Rennes 1, 2013. http://www.theses.fr/2013REN1S129/document.
Full textPortentol is a polypropionate with an unusual spirocylic structure. This natural product, which has never been synthesized, has been isolated from the lichen Rocella portentosa. To access the spiranic moiety of the portentol, we have developed a methodology to synthesize spirotetrahydropyranes through a Prins cyclization. Through the study of the scope of this reaction, an usual dynamic kinetic resolution has been highlighted. Stachybotrin C, isolated from the bacteria Stachybotrys parvispora, exhibits interesting neuritogenic and neuroprotective properties. To prepare this natural product, two synthetic routes have been investigated. The first one is based on a gold-catalyzed hydroarylation of a propargyllic ether followed by a regioselective oxidation of the resulting chromene. The second pathway involves as a key step an epoxydation/cyclisation of a phenol prepared via a Claisen rearrangment. We accomplished the synthesis of stachybotrin C, revised its structure and established its absolute configuration
Mould, Katy M. "Studies towards the total synthesis and structure elucidation of leiodolide A." Thesis, University of St Andrews, 2013. http://hdl.handle.net/10023/4113.
Full textMochirian, Philippe. "Nouvelle méthodologie de synthèse de polypropionates dérivés d'un motif anti, anti : synthèses formelles de la zincophorine." Thèse, 2007. http://hdl.handle.net/1866/17998.
Full textBrazeau, Jean-François. "Synthèse stéréosélective de motifs polypropionates via la chimie des radicaux : application à l'élaboration de l'hémisphère ouest de la narasine." Thèse, 2009. http://hdl.handle.net/1866/8837.
Full textThis thesis focuses on a new methodology for the synthesis of polypropionate stereopentads with an application to the synthesis of a natural molecule that possess interesting biological properties. The key steps of our strategy to elaborate those motifs will use radical chemistry previously developped in our group. First, the importance of synthesizing polypropionate motifs is presented. In recent years, polypropionate systems have stimulated extensive interest due to their association with a broad spectrum of biologically active targets with proven or potential use in medicine, including those with antibiotic and anticancer properties. Many of the approaches reported used chiral reagents and took advantage of double asymmetric induction. Not surprisingly, mismatched scenarios were at times noticed and yet, no single strategy has been reported leading directly to all 16 stereopentad diastereoisomers. Thus, the rapid and facile assembly of the polypropionate framework would be very beneficial and is still an active area of research. The second section of this work describes our contribution to this area with the development of a fully substrate-controlled sequence of Mukaiyama aldol reaction followed by a hydrogen transfer reaction on aldehydes having the stereotriad array. The aldol reaction can be performed under Felkin-Anh or Cram-chelate pathway to give either the 3,4-syn or 3,4-anti relationship, respectively. This reaction was optimized using different Lewis acids to give excellent yield and diastereoselectivity. We found that an excess of TiCl3(OiPr) in our Mukaiyama reactions increased the chelating ability of the Lewis acid, thus leading to improved diastereoselectivity. Low temperature 13C NMR was performed to obtain more information on the complexes present in solution. Once the radical precursors were obtained, the hydrogen transfer step was performed. Aluminum-containing Lewis acids led to the exclusive formation of the 2,3- syn isomer under the endocyclic effect while controlling factors described for acyclic molecules were sufficient enough to give the 2,3-anti as a sole diastereoisomer, such as cases in which a boron-containing Lewis acid was added prior to the tin hydride. One limitation was observed with this scenario and resolved using the exocyclic effect to access all 16 polypropionate stereopentad motifs. To further demonstrate the synthethic potential of our methodology, we engaged on the synthesis of the western hemisphere of both salinomycin and narasin. The synthetic challenges related with these molecules are numerous due to the large number of adjacent stereogenic centers. We realized that the 2,3-anti stereochemical relation of salinomycin was not selectively accessible via radical chemistry under the exocyclic effect. Different substrates were tested to understand this limitation and we concluded that the substituents on the ring impose a conformationnal bias unfavorable to good selectivty. Still, we found an alternative employing a chiral crotylsilane to access this 2,3-anti relationship α to the six-membered ring. This situation is different in the case of narasin where the β-methyl substituent blocks efficiently the hydride attack from the upper face. Impressive selectivities were observed and the synthesis of the C1-C9 fragment of narasin was accomplished in an expeditive manner. Finally, the elongation using a second sequence of stereoselective Mukaiyama aldol reaction/radical reduction followed by an aldol coupling led to the construction of the western hemisphere of narasin in 19 synthethic steps with an overall yield of 7 %. Finally, we decided to focus our attention to the chemistry of α-bromo-β- alkoxyketones in hydrogen transfer reactions. We found that their ability to give selective transformations could be beneficial in the context of synthesizing complex polypropionate motifs. The presence of a stereogenic center on the other side of the ketone seemed to have a great impact on the selectivity.
Godin, François. "Synthèse diastéréosélective du fragment C1-C13 de la zincophorine par approche combinée utilisant une séquence d'aldolisation de Mukaiyama suivie d'une réduction radicalaire." Thèse, 2008. http://hdl.handle.net/1866/7814.
Full textBrazeau, Jean-François. "Synthèse diastéréosélective des motifs polypropionate à partir des aldéhydes 2,3-syn via une séquence d'aldolisation de Mukaiyama suivie d'une réduction radicalaire contrôlées à l'aide d'acides de Lewis." Thèse, 2004. http://hdl.handle.net/1866/16750.
Full textChau, Anh. "Diastereoselective palladium-catalyzed formate reduction of allylic carbonates as a route to polypropionate systems." 2004. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=94900&T=F.
Full textFoley, Corinne N. "The Development and Application of a New Approach to the Rapid Synthesis of Polypropionate Stereotriads." Thesis, 2015. https://doi.org/10.7916/D8S18156.
Full text"Proline catalyzed enantioselective retro-aldol reaction." Thesis, 2013. http://hdl.handle.net/10388/ETD-2013-12-1320.
Full text"THE TOTAL SYNTHESIS OF MUAMVATIN." Thesis, 2012. http://hdl.handle.net/10388/ETD-2012-10-724.
Full textTambutet, Guillaume. "Synthèse stéréosélective de centres tertiaires et quaternaires par voie radicalaire et leur application à la synthèse d’analogues de nucléosides et de polypropionate." Thèse, 2017. http://hdl.handle.net/1866/20962.
Full textTownsend, Ian A. "Iridium-catalyzed C-C bond formation : development of crotylation and methallylation reactions through transfer hydrogenation." Thesis, 2012. http://hdl.handle.net/2152/ETD-UT-2012-05-5582.
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