Dissertations / Theses: 'Rearrangement'

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Mohamed, Mustafa Abdi. "Synthesis of [alpha]-allynyl and [alpha]-allylsilane amino acids by the Claisen rearrangement /." *McMaster only, 2001.

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2

Christie, David Alan. "Genome rearrangement problems." Thesis, University of Glasgow, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284780.

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Yoon, Tehshik Peter MacMillan David W. C. "The acyl-Claisen rearrangement development of a novel metal-catalyzed Claisen rearrangement and enantioselective variants of the acyl-Claisen rearrangement /." Diss., Pasadena, Calif. : California Institute of Technology, 2002. http://resolver.caltech.edu/CaltechTHESIS:01282010-153053761.

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Thesis (Ph. D.)--California Institute of Technology, 2002. PQ #3052855.
Advisor names found in the Acknowledgments pages of the thesis. Title from home page. Viewed 02/11/2010. Includes bibliographical references.

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Mountford, David Mark. "Novel Claisen rearrangement reactions." Thesis, Imperial College London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.415168.

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Copeland, Fiona B. M. "Low energy rearrangement collisions." Thesis, Queen's University Belfast, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318881.

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Lang, Stuart. "Rearrangement of organic azides." Thesis, University of Strathclyde, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.415093.

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7

Alabdullah, Basil. "Stereoselective organoborate rearrangement reactions." Thesis, Cardiff University, 2015. http://orca.cf.ac.uk/75961/.

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This thesis describes the use of organoborate rearrangement reactions to generate quaternary carbon centres, with the ultimate goal of exploring new procedures for the asymmetric synthesis of chiral quaternary carbon centres. Chapter One: this chapter contains a historical review of the use of organoboranes in organic synthesis, focusing mainly on the use of boronic esters in asymmetric organic synthesis. Chapter Two: this chapter focuses on attempts at developing a catalytic method for the generation of quaternary stereocentres using migration reactions of boronic esters with n-butyllithium in the presence of chiral catalysts. This study showed that the reaction is stoichiometric in the absence of the Lewis acid. However, there were strong indications of catalytic turn over in some experiments. Chapters Three and Four: these chapters focus on attempts at designing a chiral version of the DCME reaction using sulfur compounds. Chapter Three focuses on attempts at evaluating a heterocyclic system, specifically a dithiane, as a stereocontrol agent in its reaction with trialkylboranes. The study showed that using 2-methoxy-1,3-dithiane-oxide achieved formation of the double and triple migration product but in poor yield. Chapter Four contains a detailed investigation into the synthesis and evaluation of non-cyclic sulfur compounds such as sulfoxides, sulfoximines, sulfilimines and sulfones for generation of chiral tertiary alcohols. The study of the reaction of dichloromethyl phenyl sulfoxide with trialkylboranes showed a new type of aldol-like reaction. This reaction was utilised to synthesise a series of new compounds. Also, the study of the reaction of dichloromethyl-p-tolyl sulfone with trialkylboranes showed a new type of reaction by replacing the hydrogen with the alkyl group from the trialkylborane. Finally, the study of the reaction of N-methyl-S-(dichloromethyl)-S-phenylsulfoximine with trialkylboranes showed production of the desired triple migration product in moderate to very good yield.

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Hester, Alison J. "The anionic thia-fries rearrangement." Thesis, University of Bristol, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.430204.

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Sollogoub, Matthieu. "Le triisobutylaluminium (tibal) et les sucres : rearrangements et debenzylation le ti(iv) un autre agent de rearrangement." Paris 6, 1999. http://www.theses.fr/1999PA066480.

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Le triisobutylaluminium (tibal) est le reactif de choix pour effectuer la transposition du carbone et de l'oxygene dans un ether d'enol dont l'ether possede un groupement electro-donneur en. Dans le domaine des sucres ce rearrangement permet la transformation, unique, d'un glycoside en carbocycle avec conservation de l'aglycone. Cette reaction est aussi effectuee par cl 3tioipr. Nous avons exploite cette reaction en l'appliquant a des disaccharides dans le but de synthetiser de facon directe des carba-disaccharides. Nous avons aussi reussi a transformer des composes dont l'aglycone n'est pas oxygenee (s-, se-, c-glycosides). Finalement nous avons mis en evidence une autre action remarquable du tibal sur les sucres : la de-o-benzylation regioselective des composes -methyl perbenzyles.

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10

Yang, Yanbo. "Pd0-Catalyzed Formal 1,3-Diaza-Claisen Rearrangement. Design And Development Of Cationic 1,3-Diaza-Claisen Rearrangement." ScholarWorks @ UVM, 2014. http://scholarworks.uvm.edu/graddis/261.

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The dissertation describes Pd0-catalyzed formal 1,3-diaza-Claisen rearrangement and the design and development of cationic 1,3-diaza-Claisen rearrangement. Our previous work has shown that isocyanates react with azanorbornenes and azabicyclo[2.2.2]octenes under thermal conditions to afford zwitterionic intermediates that undergo a thermal 1,3-diaza-Claisen rearrangement to give both ureas and isoureas. However, some azanorbornenes and azabicyclooctenes failed to rearrange or proceeded in low yields. To address these challenging substrates for the thermal 1,3-diaza-Claisen rearrangement, we have developed a Pd0-catalyzed formal 1,3-diaza-Claisen rearrangement. Interestingly, under Pd0-catalyzed condition, both isocyanates with electron-withdrawing groups and isocyanates without electron-withdrawing groups react with azanorbornenes and azabicyclo[2.2.2]octenes to provide ureas as the only products in high yields. More importantly, the reactions that failed under thermal conditions were all successful under Pd0-catalysis. In addition to azanorbornenes and azabicyclo[2.2.2]octenes, other ring systems were also investigated. Pd0 catalysis has broadened the scope of tertiary allylic amines that react with isocyanates to afford 1,3-diaza-Claisen rearrangement products. In the presence of p-TsCl and NEt3, allylaminopropyl benzyl ureas were initially dehydrated to form protonated carbodiimides whose presence was confirmed by the infrared absorption frequency at 2100 cm-1 which is the characteristic band of -N=C=N-; then the in situ generated protonated carbodiimides were poised for further cationic 1,3-diaza-Claisen rearrangement to afford synthetically challenging guanidines. The effect of acid on the rearrangement was ascertained by the fact that no rearrangement product was observed by simply heating free base carbodiimide 3.10 in benzene at reflux. Other dehydration reagents, such as Tf2O, Ts2O, MsCl were also investigated, and none of them provide satisfactory results. A selection of allyamino benzyl ureas with different tether length, substituents, or in varied ring systems, were synthesized to explore the scope of this methodology. This methodology works best at allylaminopropyl benzyl ureas, and the substituents on the benzyl group does not seem to affect the reaction rate in a significant way.

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Silvary, Sunil Raj. "StereoElectronic Controls in the Preparation of 1-Benzyl-l, 2, 4, 5-Tetrahydro-(3H)-2-Benzazepin-3-ones Via Beckmann Rearrangement." Fogler Library, University of Maine, 2007. http://www.library.umaine.edu/theses/pdf/SilvarySR2007.pdf.

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Pocock, Ian. "Novel cascade aryne-capture/rearrangement reactions." Thesis, University of Huddersfield, 2014. http://eprints.hud.ac.uk/id/eprint/23743/.

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Arynes are reactive intermediates that have been an academic curiosity for over a century. A recent renaissance of interest in the chemistry of these intermediates can be traced back to the development of ortho-(silyl)aryl triflates as aryne precursors. The application of aryne chemistry outside academia has been precluded by the expense and laborious preparation of these precursors. Diphenyliodonium-2-carboxylate has been shown to be a stable and inexpensive benzyne precursor, however application has been limited due to the high temperature (>160 ºC) and long reaction times required to generate benzyne by this protocol. Described within is an investigation whereby diphenyliodonium-2-carboxylate is successfully decomposed using microwave irradiation to generate benzyne. This proof of concept investigation shows diphenyliodonium-2-carboxylate can be applied as an off-the-shelf benzyne precursor; by using microwave radiation, significantly reduced reaction times and lower b.p. solvents can facilitate a more universal application of this protocol than previously described. The investigation into the reactions of allylamino malonates with arynes is also described. Simple allylamino malonates are shown to perform a novel cascade aryne capture/ring-closure/[2,3]-rearrangement to generate indolin-3-one products. The influence of substitution of the indolin-3-one products on the photophysical properties is probed. Tetrahydropyridine derived aminomalonates result in a ring contraction by [2,3]-rearrangement to N-phenyl pyrrolidine products. Further investigations show N-allyl proline methyl esters also generate indolin-3-one products by this novel cascade mechanism. The photophysical properties of these products are also probed. N-diallylalanine methyl ester is shown to generate indolin-3-one with benzyne however N-allyl sarcosine ethyl ester generates the N-phenyl -allylated amino esters product by aryne capture/[2,3]-rearrangement.

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Komsta, Zofia Aleksandra. "1,2-metallate rearrangement of carbohydrate derivatives." Thesis, University of Leeds, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.534826.

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Hickford, Paul J. "Novel rearrangement reactions of oxetane systems." Thesis, University of Bristol, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.492838.

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15

Chung, Hunsuk. "Stereocontrolled synthesis and rearrangement of epoxides." Thesis, Imperial College London, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.502474.

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Challinor, Lee. "Allylic amine synthesis via sulfimide rearrangement." Thesis, Imperial College London, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.485415.

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This thesis reports the development of a novel asymmetric route towards a variety of NBoc protected allylic amines. This was achieved by creating an organocatalytic asymmetric transformation of aldehydes into a diverse range of allylic sulfides, and then applying a [2,3]-sigmatropic rearrangement with chirality transfer to afford five target motifs that will be discussed in individual chapters. Chapter One. introduces the general topi:along with supporting references. Chapter Two focuses on allylic amines and a [2,3]-sigmatropic rearrangement as a method ofasymmetric C-N bond construction via sulfimidation. The use of an oxaziridine reagent as an electrophilic source ofNBoc to induce rearrangement of prochiral allylic sulfides is then discussed prior to optimisation of a chemoselective version utilising chiral substrates..The chirality transfer is addressed in light of contradictory evidence, and confirmed as complete with simple aliphatic allylic sulfides and several unexplored substrates. Chapter Three highlights vinyl glycines and the development of an organocatalytic preparation of chiral substrates which had previously only been available from a limited chiral pool. Both (E) and (2) allylic sulfides were selectively prepared and the creation of a one-pot amination-rearrangement/N-S- bond cleavage sequence afforded both optical isomers of the target compounds with a variety of y-substituents. Chapter Four focuses on quaternary substituted vinyl glycines which were prepared with an array of a- and y-substituents by optimising the asymmetric organocatalytic preparation of geometrically enriched tri-substituted allylic sulfides through variation ofthe aldehyde and olefinating reagent respectively. Chapter Five discuses allylic afluoro aminoacids and their inherent instability. Chapter Six covers allylic a-aminophosphonates where the organocatalytic preparation of chiral vinylic phosphonates was achieved along with their amination-rearrangement, but the chirality transfer remains to be examined. Chapter Seven concludes our findings and outlines future research. Chapter Eight provides experimental details with spectroscopic and physical data for new compounds.

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Noble, Lynda. "Photochemical rearrangement and dehalogenation of polyhalogenodiazines." Thesis, University of Sunderland, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329818.

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Topiwala, Upendra P. "Biomimetic radical spirocyclisation and rearrangement chemistry." Thesis, University of Nottingham, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338494.

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Button, Martin Andrew Colin. "Development of the amino-cope rearrangement." Thesis, University of Huddersfield, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285613.

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O'Mahony, Donogh John Roger. "Rearrangement and trapping of organozinc carbenoids." Thesis, University College London (University of London), 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308938.

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21

Yang, Yuxing. "Synthesis and rearrangement of silsesquioxane cages." Thesis, Open University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.393194.

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22

Tomlin, Paula Margaret. "Studies towards an asymmetric Favorskii rearrangement." Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.612918.

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23

King, Jennifer E. "Robust Rearrangement Planning Using Nonprehensile Interaction." Research Showcase @ CMU, 2016. http://repository.cmu.edu/dissertations/933.

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As we work to move robots out of factories and into human environments, we must empower robots to interact freely in unstructured, cluttered spaces. Humans do this easily, using diverse, whole-arm, nonprehensile actions such as pushing or pulling in everyday tasks. These interaction strategies make difficult tasks easier and impossible tasks possible. In this thesis, we aim to enable robots with similar capabilities. In particular, we formulate methods for planning robust open-loop trajectories that solve the rearrangement planning problem using nonprehensile interactions. In these problems, a robot must plan in a cluttered environment, reasoning about moving multiple objects in order to achieve a goal. The problem is difficult because we must plan in continuous, high-dimensional state and action spaces. Additionally, during planning we must respect the physical constraints induced by the nonprehensile interaction between the robot and the objects in the scene. Our key insight is that by embedding physics models directly into our planners we can naturally produce solutions that use nonprehensile interactions such as pushing. This also allows us to easily generate plans that exhibit full arm manipulation and simultaneous object interaction without the need for programmer defined high-level primitives that specifically encode this interaction. We show that by generating these diverse actions, we are able to find solutions for motion planning problems in highly cluttered, unstructured environments. In the first part of this thesis we formulate the rearrangement planning problem as a classical motion planning problem. We show that we can embed physics simulators into randomized planners. We propose methods for reducing the search space and speeding planning time in order to make the planners useful in real-world scenarios. The second part of the thesis tackles the imperfect and imprecise worlds that reflect the true reality for robots working in human environments. We pose the rearrangement planning under uncertainty problem as an instance of conformant probabilistic planning and offer methods for solving the problem. We demonstrate the effectiveness of our algorithms on two platforms: the home care robot HERB and the NASA rover K-Rex. We demonstrate expanded autonomous capability on HERB, allowing him to work better in high clutter, completing previously infeasible tasks and speeding feasible task execution. In addition, we show these planners increase autonomy for the NASA rover K-Rex by allowing the rover to actively interact with the environment.

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O'Brien, Alexander. "Acyclic stereocontrol in the Claisen rearrangement." Thesis, Imperial College London, 2010. http://hdl.handle.net/10044/1/5560.

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This thesis examines the issues of acyclic stereocontrol in the Claisen rearrangement, with particular emphasis on the effects of exopericyclic stereocentres – i.e. those adjacent to the array of atoms directly involved in the sigmatropic process. It is divided into three main parts: The first section provides a review of the field of acyclic stereocontrol. The models used to explain the development of relationships between stereocenters in systems lacking well-defined conformational constraints are discussed. This is an established field and particular emphasis is given to recent developments in the modelling of such systems. The second section discusses the results of our studies. Previous examples of exopericyclic stereocontrol in sigmatropic rearrangements are shown. Studies are presented that explore the importance of heteroatom-bearing stereocenters and effects of olefin substitution pattern on the manner and extent of stereoselectivity. Our efforts to exploit these stereochemical effects in the synthesis of small molecules are then presented. A novel reaction sequence is presented in which equilibrating mixtures of allylic azides undergo stereoselective Claisen rearrangements and further chemistry of the products of this transformation is then explored. These studies, and attempts to deploy them in synthesis allow us to draw conclusions on the nature of acyclic stereocontrol in the Claisen rearrangement. The third section contains experimental procedures and characterisation data for all compounds prepared.

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Farran, Daniel. "Le rearrangement transannulaire de Lactames actives." Montpellier 2, 2007. http://www.theses.fr/2007MON20132.

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Chanda, Swapan Kumar. "Molecular rearrangement and transformation in triterpenes." Thesis, University of North Bengal, 2002. http://hdl.handle.net/123456789/701.

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Zheng, Chunfang. "Genome rearrangement algorithms applied to comparative maps." Thesis, University of Ottawa (Canada), 2006. http://hdl.handle.net/10393/27313.

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The Hannenhalli-Pevzner algorithm for computing the evolutionary distance between two genomes is very efficient when the genomes are signed and totally ordered. But in real comparative maps, the data suffer from problems such as coarseness, missing data, no signs, paralogy, order conflicts and mapping noise. In this thesis we have developed a suite of algorithms for genome rearrangement analysis in the presence of noise and incomplete information. For coarseness and missing data, we represent each chromosome as a partial order, summarized by a directed acyclic graph (DAG). We augment each DAG to a directed graph (DG) in which all possible linearizations are embedded. The chromosomal DGs representing two genomes are combined to produce a single bicoloured graph. The major contribution of the thesis is an algorithm for extracting a maximal decomposition of some subgraph into alternating coloured cycles, determining an optimal sequence of rearrangements, and hence the genomic distance. Also based on this framework, we have proposed an algorithm to solve all the above problems of comparative maps simultaneously by adding heuristic preprocessing to the exact algorithm approach. We have applied this to the comparison of maize and sorghum genomic maps on the GRAMENE database. A further contribution treats the inflation of genome distance by high levels of noise due to incorrectly resolved paralogy and error at the mapping, sequencing and alignment levels. We have developed an algorithm to remove the noise by maximizing strips and tested its robustness as noise levels increase.

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Pfeifer, Patrick F. "Dynamic decomposition| A creative rearrangement of "waste"." Thesis, Northern Arizona University, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=1537801.

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This thesis dissects the category of "waste," examining conventional modes of response to the people, places, and things considered waste, and challenging the patterns of both linear disposal and cyclical recycling. I argue that both ways of thinking about "waste" actually share the same problematic roots and reproduce the same problematic logics, and that both oversimplify the diverse spectrum of potentials and histories contained within "waste."

Using a methodology that links personal narrative with historical analysis, I decompose the very idea of waste to understand the constellation of factors and processes that actively produce "waste" in contrast with "value," discussing histories of recycling and disposal in tandem with histories of capitalism, colonialism, and industrialization. With recent composting work at Northern Arizona University serving as both metaphor and example throughout this thesis, I build an alternative to the existing paradigm of waste, offering a more complex, diverse, dynamic, and interconnected framework for relating to and redefining "waste."

To do this, I explore not only theoretical and conceptual strategies for revealing and amplifying the hidden diversity of alternate values, benefits, and relationships around (non)waste, but also transition theory to practice by mapping out ways to physically implement these ideas through specific projects and actions that actively shift the ways people think about and interact with "waste" on a daily basis. By mapping out the theory and action involved in re-shaping human interactions with the things considered "waste," this thesis hopes to inspire others to keep working with these ideas and to continue developing projects that transition from a state of waste to (non)waste by creating a more socially and ecologically ethical paradigm of relationships beyond "waste."

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Lee, Gary Peter. "Enantioselective #alpha#-deprotonation/rearrangement of meso-epoxides." Thesis, University of Oxford, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298271.

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Renny, Joseph S. "The Newman-Kwart Rearrangement : Molecularity and Catalysis." Thesis, University of Bristol, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.525440.

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Owens, Jonathan. "The rearrangement of some substituted cyclopropylcarbinyl radicals." Thesis, University of Strathclyde, 1991. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21502.

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The ring-opening of cyclopropylcarbinyl radicals has been postulated to proceed via a dipolar transition state. In this thesis it was hoped to delineate some of the factors that influence the rate of ring-opening of some substituted cyclopropylcarbinyl radicals and hence estimate their relative importance. This would allow the involvement of the dipolar transition state in the ring-opening process to be assessed. In order to achieve the above objective it was necessary to synthesise methylcyclopropanes with substituents at both the a-position and the 2-position. Such compounds should readily react with t-butoxyl radicals to give a series of cyclopropylcarbinyl radicals. The bulk of the synthetic work was in two parts, the first involved synthesis of 2,2-difluoro substituted cyclopropanes, to determine the influence of fluorine substituents in the cyclopropane ring. The second section involved cyclopropanations using carboethoxycarbene. Radicals were generated, from successfully synthesised precursors, and their electron spin resonance spectra recorded. The data obtained provided evidence for the involvement of a dipolar transition state in some of the ring-opening rearrangements. However, in several of the radicals other factors are clearly influencing the observed ring-opening. In another section of the work the effect of phenyl and ferrocenyl substituents on the ring-opening of cyclopropylcarbinyl radicals was assessed.

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32

Davies, Elizabeth Anne. "Arranging an enantioselective aza-[2,3]-Wittig rearrangement." Thesis, University of Nottingham, 2009. http://eprints.nottingham.ac.uk/10701/.

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The use of the aza-[2,3]-Wittig sigmatropic rearrangement in the synthesis of α,α-disubstituted α-amino acids has been investigated with the emphasis on obtaining enantioenriched rearrangement products. It was hoped that an enantioenriched precursor could form an axially chiral enolate which would impart chiral information on the product. To access an axially chiral enolate, the rearrangement conditions of a known precursor 66 have been studied. Varying temperature had no effect on the enantioselectivity. Different bases were investigated with only KHMDS instigating rearrangement. Upon treatment with KHMDS, 66 rearranged to form the desired product as well as pyrrolidine 119. The temperature of the rearrangement was varied; at lower temperatures only 119 was isolated. A range of precursors with potential chelating groups has been synthesised. The effect of temperature on aza-[2,3]-Wittig rearrangement of these precursors was investigated; however, rearrangement did not occur at below temperatures of around - 40 ºC and this temperature was not low enough to provide an axially chiral enolate intermediate, as evidenced by the racemic nature of the rearrangement products. The aza-[2,3]-Wittig rearrangement of amide precursor 63 was also investigated. The only product isolated upon treatment with KH and 18-crown -6 was pyrrolidine 158. Precursors 150 (derived from tert-leucine), and oxazoline 159 were subjected to rearrangement conditions. Deuterium quench studies showed that, in both cases, deprotonation had not occurred, possibly due to the sterically encumbered enolate that would form upon deprotonation. Further investigations into the cyclisation of 66 showed that the probable mechanism was aza-[2,3]-Wittig rearrangement, followed by cyclisation. The resulting pyrrolidine was formed as a single diastereomer. Precursors 65, 67 and 175 also underwent cyclisation in a similar manner. The relative stereochemistry of these pyrrolidines was determined by nOe experiments. Studies of the mechanism of cyclisation of 63 were inconclusive. It is unknown whether pyrrolidine 158 is formed by an incomplete rearrangement or a fast rearrangement-cyclisation sequence. The utility of the cyclisation was further demonstrated by Fleming oxidation of the dimethylphenylsilyl group and protiodesilylation of 119.

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Smyth, Donald. "Acid induced rearrangement to form cyclohexadienyliron complexes." Thesis, University of East Anglia, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386100.

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Hoppe, Anne. "Investigation of E4 Orf3-mediated ND10 rearrangement." Thesis, University of Warwick, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.479289.

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Carbery, David Ross. "Development of a cobalt mediated rearrangement reaction." Thesis, University of Sheffield, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.274952.

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Mould, Roger James. "Aza-Wittig rearrangement of aziridines to piperidines." Thesis, University of Exeter, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296237.

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Provan, Andrew. "Antigen receptor rearrangement in the lymphoid malignancies." Thesis, University of Southampton, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242480.

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Baker, M. G. "Investigations on the type-III rearrangement problem." Thesis, University of Cambridge, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372877.

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Coulson, Bethan. "Sigmatropic rearrangement-metathesis based approaches to cyclopentadienes." Thesis, Imperial College London, 2017. http://hdl.handle.net/10044/1/59037.

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This thesis is divided into four chapters. Chapter one is a review of cyclopentadienes (Cps), and is split by sub-classification of applications in organometallics, applications in organic methodology, synthesis of complex Cps from post carbocycle modification and de novo synthesis of Cp. Chapter two introduces the decarboxylative Claisen rearrangement (dCr) and details investigations of the application of this reaction towards Cp synthesis using three different activating groups. Chapter three focuses on the decarboxylative Claisen rearrangement (dCr) from a computational aspect. It begins with a brief review of the mechanism of the [3,3]-sigmatropic rearrangement and examples of density functional theory (DFT) to rationalise Ireland-Claisen rearrangements. The kinetic data of [3,3]-sigmatropic rearrangement of tosyl malonates is studied and compared to DFT calculations. The method devised is tested on literature dCr reactions and then used predictively to interpret synthetic outcomes. Chapter four provides experimental procedures and characterisation data.

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40

Harling, John David. "Preparative radical rearrangement reactions for organic synthesis." Thesis, Imperial College London, 1989. http://hdl.handle.net/10044/1/47464.

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41

Clelland, Iain C. "Solid-state rearrangement reactions of acylated aminopyrazoles." Thesis, University of Edinburgh, 1999. http://hdl.handle.net/1842/14565.

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The thermally induced solid-state rearrangement reactions of acylated aminopyrazoles were investigated. The precursors were generally formed by mono-acylating 3-aminopyrazole with an acid chloride in solution, and obtaining an isolated individual isomer by dry fresh chromatography. The rearrangements proceed under remarkably mild conditions (at room temperature or below), at temperatures of up to 100°C below the melting point. The reaction can still occur in the melt but not to any extent in solution. The reaction proceeds in all cases from the 1 (r) 3-isomer and from the 2 (r) 3-isomer and for many acyl substituents the rearrangements occur in tandem with the 2-isomer rearranging to the 1- and 3-isomers concurrently. However the migration of the acyl group from the 1 (r) 2-isomer has not been seen as might have be expected. The solid-state rearrangements work for a wide range of acyl substituents, even occurring when the structure of the pyrazole ring is altered or when different ring systems are used (e.g. indazoles). The half-lives of reaction for individual acyl substituents and isomers vary from hours to years. The tendency is for the rearrangement of the 2 (r) 3-isomer to be faster than its counterpart 1 (r) 3, though there are exceptions to this. The overall conclusion is that, having investigated a wide range of migrating acyl substituents, neither steric, nor electronic, nor melting point factors, are responsible for controlling the rate of this solid-state rearrangement. A study of the crystal structures of a range of structurally diverse 1- and 2-acyl-3-aminoipyrazoles reveals that a non-Topochemical mechanism is operating and so the reactions are thought to take place at crystal defects. The reaction is observed not to occur throughout the bulk of the crystal when observed under a microscope and in addition the integrity of the crystal is not maintained throughout the reaction.

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42

Ekman, Diana. "Domain rearrangement and creation in protein evolution /." Stockholm : Department of Biochemistry and Biophysics, Stockholm university, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-8295.

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43

Čiuladaitė, Živilė. "Chromosomų struktūros persitvarkymų įvairovė Lietuvoje ir genetinė jų reikšmė." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2008~D_20110709_152250-31963.

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Chromosomų struktūros persitvarkymai gali lemti įvairius žmogaus sveikatos sutrikimus. Netgi chromosominės ligos, pvz., Dauno ar Ternerio sindromai, gali būti nulemtos ne chromosomų skaičiaus, bet chromosomų struktūros persitvarkymų. Chromosomų trūkiai gali vykti bet kurioje chromosomos dalyje, tai lemia įvairius chromosomų struktūros pokyčius, tačiau tik dalis jų yra suderinami su gyvybinėmis funkcijomis ir yra nustatomi postnataliai. Chromosomų struktūros persitvarkymai, priklausomai nuo to, subalansuoti ar nesubalansuoti, lemia įvairias dismorfines anomalijas arba vaisingumo problemas. Jų nustatymas yra svarbus genetiniam konsultavimui. Šio drabo tikslas- įvertinti chromosomų struktūros persitvarkymų, nustatytų VUL SK MGC 2002 – 2008 m., įvairovę ir genetinę jų reikšmę. Tam, kad būtų įvertinta chromosomų struktūros persitvarkymų įvairovę, buvo analizuojami 2002-2008 metais atlikti kariotipo tyrimai. Remiantis rezultatais galima teigti, kad dažniausias chromosomų struktūros pakitimas yra reciprokinė translokacija, kuri dažniausiai lemia nevaisingumą bei savaiminius persileidimus. Didžiausia chromosomų struktūros pakitimų įvairovė nustatyta X chromosomoje.Rutininė citogenetinė kariotipo analizė yra svarbi ir tais atvejais, kai atliekamas FISH tyrimas naudojant tam tikrai genetinei sričiai specifinį žymenį, kadangi skirtingi chromosomų struktūros persitvarkymai gali lemti panašų fenotipą.
Chromosome structural rearrangements could cause various human health problems. Even Down’s or Turner’s syndromes, which are usually determined by chromosome number change, in some cases could be caused by chromosome structure abnormalities. Structure rerrangements of autosomes, depending on whether it is balanced origin or not, are responsible for various dysmorphic abnormalities or fertility problems. Chromosome breakpoints can occur in any part of chromosome and form any type of rearrangement, but only part of them could be compatible with vital functions and detected postnatally. Chromosome structural rearrangements in many cases are unique and only particular ones are more common. The objective of this work was to assess the diversity of chromosome structural rearrangements and their implication to the human genetic. Cytogenetic analysis of karyotype was performed using G-banding and FISH techniques. Cytogenetic analyses of 76 patients using routine cytogenetic analysis and 20 patients using FISH method have been performed. In order to assess the variety of chromosome structural rearrangements, the results of karyotype analyses performed in Department of Human and Medical Genetics, Faculty of Medicine, Vilnius University during the period of 2002–2008 were reviewed. On the basis of obtained results a conclusion can be drawn that translocation is the most frequent chromosome structure rearrangement type, comprising 44,3% of all our cases. X chromosome is the most... [to full text]

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44

Law, Chunyin Marshall. "Novel Catalytic Reactions Enabled by Metal-Induced Boronate Rearrangement:." Thesis, Boston College, 2020. http://hdl.handle.net/2345/bc-ir:108761.

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Thesis advisor: James P. Morken
This dissertation will discuss the development of three methodologies that take advantage of the intrinsic reactivity of organoboron “ate” complex to undergo boronate rearrangement. The first chapter will describe a nickel-catalyzed conjunctive cross-coupling reaction between 9-BBN boranes and aryl halides. This process provides secondary organoboranes enantioselectively from readily available alkenyl starting materials. The second chapter will describe the development of conjunctive cross-coupling between 9-BBN boranes and acyl electrophiles. We will highlight its unique value in the syntheses of β-hydroxyl carbonyls and show that this reaction is complementary to the aldol reaction. In the third and last chapter of this manuscript, we report the conjunctive crosscoupling reaction of simple achiral borylenynes towards the enantio- and diastereoselective synthesis of α-borylallenes, which provides α-allenols upon oxidative workup
Thesis (PhD) — Boston College, 2020
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry

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45

Garcia-Torres, Jason. "Development of a dual Fries-Claisen rearrangement strategy." Thesis, Loughborough University, 2012. https://dspace.lboro.ac.uk/2134/11002.

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Synthetic approaches towards linear fused carbon rings have been developed over the last decades due to their high interest as compounds with potential antibiotic activity and as organic electronics. The application of a novel iterative route towards linear fused carbon ring systems could provide a versatile new mode of access to complex substituted ring systems. Studies have previously demonstrated the use of an allylation-double Claisen-RCM sequence to build fused carbon rings (C). In this thesis we described our work to expand the use of this methodology by developing milder reaction conditions that could be applied to a wider range of compounds. This novel methodology was applied towards the synthesis of benzodifuran compounds (D). Our work was extended by developing, for the first time, a mixed Fries-Claisen rearrangement strategy which furnishes template (F), a key intermediate in the synthesis of pyranonaphthoquinones (G). Our work culminated in a new approach to the pyranonaphthoquinone natural products eleutherin (H) and isoeleutherin (I). [Figures missing from abstract].

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46

Hsieh, Yihhuang. "Reexamination of a putative (1s,4s) sigmatropic rearrangement." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/mq24160.pdf.

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Blid, Jan. "Asymmetric [2,3]-Sigmatropic Rearrangement of Allylic Ammonium Ylides." Doctoral thesis, Stockholm, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-430.

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Burchard, Almut. "Cases of equality in the riesz rearrangement inequality." Diss., Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/29194.

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49

Cameron, Iain Donald. "Rearrangement and electrophilic trapping of chiral lithiated epoxides." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.393354.

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Al-Shamali, M. A. "Heterogeneous catalytic procedures for rearrangement of epoxide compounds." Thesis, Swansea University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.635724.

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The third chapter summarizes the investigation of acid-catalyzed reactions of epoxides to form carbonyl compounds using different acidic zeolites. Initial reaction involved styrene oxide as a model example, which had been reported to be converted to phenylacetaldeyhyde over HZSM-5 zeolite at 90°C, under nitrogen, in the presence of toluene as solvent. The investigation began with changing the reaction conditions for this reaction, such as temperature, solvent, and silica to alumina ratio of the zeolite, in order to show the effect of each factor on the percentage yield of phenylacetaldehyde obtained, and the conclusion of this study was to define the optimum conditions for rearrangement of styrene oxide by H-zeolite catalysts. The methodology was then tested on a number of para-subtituted styrene oxides to show the effect of different groups on the rearrangement process. The effect of re-using the HZSM-5 catalyst, after calcination, was tested in the rearrangement of styrene oxide, and provided excellent results. Secondly, the methodology was tested on aliphhatic epoxides, such as 1,2-epoxyoctane, and cycloepoxides such as cyclohexene oxide. Finally the effects of large pore zolites such as zeolite beta on disubtituted epoxides such as trans and cis-stilbene oxides and diphenylethene oxide were tested. Chapter four summarizes studies of the base-catalyzed reaction of epoxides to form allylic alcohols as main products using different catalysts. First, solid supports such as γ-alumina were used to support the reagent such as KNO₃ or NaOH/Na in order to get solid catalyst which has high basic strength (H. higher then 26.5). These prepared catalysts were tested as superbases for the rearrangement of epoxides to give the corresponding allylic alcohols, but from this piece of work the results were unsuccessful under various conditions. According to the literature the conversion of epoxides to allylic alcohols can be achieved with lithium amide reagents. In this study lithium amide reagents attached to Merrifield's resin were produced and then reacted with epoxides in solvents such as terahydrofuran (THF). The reactions of such lithium amide polymers with epoxides in THF provided excellent results.

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