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1
Lau, Shing Hing. "Organic synthesis : taming chemistry using enabling technologies." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/273347.
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This thesis describes the application of flow chemistry to discovery and development of medicinal compound synthesis and new chemical methodologies respectively. It is divided into three distinct sections. The first section addresses a brief introduction to flow chemistry, highlighting the advantages and challenges that have been faced in the past and present and also the outlook to the future. The second section reports the integration of machine-assisted methods with batch processes to produce two medicinal compounds, a precursor to the sacubitril and OZ439 respectively. In the respect to the precursor to sacubritil, a flow-batch integrated synthesis is developed to provide the desired product in 54% yield over 7 steps from commercially available 4-iodophenyl. In particular, a tube-in-tube gas flow reactor was employed in three gas-liquid reactions without the need for installing a costly highpressure autoclave. These gas-lquid reactions were an ethylene Heck coupling reaction, an anti-Markovnikov Wacker oxidation and a rhodium-catalysed stereoselective hydrogenation respectively. In addition, a diastereoselective Reformatsky-type carbethoxyallylation using zinc metal was also highlighted in this synthesis to install an important stereocentre. A new antimalarial agent, OZ439 containing a trioxolane unit as the main structural feature, has the unique property of providing a single-dose cure for malaria in humans and has recently completed phase IIb trials. A machine-enabled process for the preparation of OZ439 was developed in 33% overall yield over 5 steps without the need of column chromatography purification. This preparation features a selective continuous hydrogrenation, Griesbaum ozonlysis and a Zn-catalysed amide reduction in the present of triethoxylsilane. The third section contains the development of two new methodologies of diazo compounds with organoboron compounds. The first methodology involves an in situ generation of transient allylic boronic species by reacting TMSCHN2 and E-vinyl boronic acids in flow, followed by subsequent trapping with a range of aldehydes (15 examples, 55-97% yield) and on a large scale (10 mmol) to provide homoallylic alcohols with high diastereoselectivity (>20:1 dr confirmed by 1H NMR). This multicomponent metal-free reaction could also be applied under batch conditions (20 further examples, 60-82% yield). The second methodology involves the preparation of an organodimetallic compound, α-trimethylsilyl benzylboronic acid pinacol esters, by reacting TMSCHN2 and phenylboronic anhydrides (21 examples, 60-91% yield), and the development of their applications as bifunctional building blocks to complex structures.
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Liu, Zhijian. "Novel aryne chemistry in organic synthesis." [Ames, Iowa : Iowa State University], 2006.
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Pearson, Christopher I. "Lithiated azetidine and azetine chemistry." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:cf3c942f-80de-4092-a38d-11006ccbb9ce.
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This work describes developments in new azetidine and azetine chemistry; specifically, methods developed for the introduction of functionality α- to nitrogen in both ring systems, with additionally in situ formation of the latter system, from azetidine substrates. Chapter 1 discusses the growing importance of azetidines, and the current methods available for making substituted azetidines by ring formation. Further discussion comprises of current sp3 C–H activation approaches α- to nitrogen in heterocyclic compounds as potential methods for sp3 C–H activation on azetidines to give substituted azetidines. Previous work by the Hodgson group in this area is detailed. Chapter 2 describes the advance made towards 2,3-disubstituted azetidines using the thiopivaloyl protecting/activating group, where the latter plays a key role. Optimisation, scope, selectivity and mechanistic insight into the α-deprotonation–electrophile trapping of a 3-hydroxy azetidine system is discussed, which successfully gives access to a range of 3-hydroxy-2-substituted azetidines. Preliminary investigations with 3-alkyl-2-substituted azetidines are also described. Chapter 3 describes the development of a straightforward protocol to make 2-substituted-2- azetines, a rarely studied and difficult to access 4-membered azacycle subclass, from readily accessible azetidine starting materials using α-deprotonation–in situ elimination followed by further α-lithiation–electrophile trapping. Extension of this methodology by transmetallation from the intermediate organolithium to the organocuprate, resulting in greater electrophile scope, is also described.
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Roper, Kimberley Ann. "New flow chemistry methods for organic synthesis." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.607846.
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Short, Robert Paul 1951. "Organoboranes in organic synthesis." Thesis, Massachusetts Institute of Technology, 1989. http://hdl.handle.net/1721.1/14204.
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Coates, Helen Margaret. "Synthetic studies towards stemofoline synthesis." Thesis, University of Southampton, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238730.
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Tilliet, Mélanie. "Synthesis and study of new oxazoline-based ligands." Doctoral thesis, KTH, Organisk kemi, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4858.
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This thesis deals with the study of oxazoline-based ligands in metal-catalyzed asymmetric reactions. The first part describes the synthesis of six new bifunctinal pyridine-bis(oxazoline) ligands and their applications in asymmetric metal-catalysis. These ligands, in addition to a Lewis acid coordination site, are equipped with a Lewis basic part in the 4-position of the oxazoline rings. Dual activation by means of this system was probed in cyanide addition to aldehydes. The second part is concerned with the synthesis of two pyridine-bis(oxazoline) ligands bearing bulky triazole groups in the 4-position of the oxazoline rings and a macrocyclic ligand consisting of a pyridine-bis(oxazoline) moiety and a diaza-18-crown-6 ether. The synthesis of these compounds benefits from the use of “click chemistry”. The ligands thus obtained were tested in different asymmetric catalytic reactions. Complexation studies with different bifunctional molecules that could bind into the cavity of the macrocycle were carried out using NMR spectroscopy. A third chapter is devoted to the synthesis of a supported pyridine-bis(oxazoline) catalyst and its use in catalysis. The pyridine-bis(oxazoline) ligand was efficiently connected to a polystyrene resin via a robust triazole linker. This resin could be employed in different metal-catalyzed asymmetric reactions and good results were obtained in terms of yield and enantioselectivity. Moreover, this polymer-bound ligand could be easily and efficiently recycled. Finally, the last part deals with the use of a hydroxy-containing phosphinooxazoline ligand in the hydrosilylation of imines and in the asymmetric intermolecular Heck reaction. A cationic iridium complex of this ligand was studied by NMR spectroscopy.QC 20100914
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Ince, Julie. "Synthesis and chemistry of methyleneaziridines." Thesis, University of Exeter, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267223.
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Pearson, Jem M. "Hydrogen-bonding motifs for non-covalent synthesis." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:f0630898-35b4-4c74-bc31-dfd252c2ee26.
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This work describes the design and synthesis of a set of four organic molecules that are intended to hydrogen-bond to each other in a pairwise manner. The four hydrogen-bonding units, termed ‘A’, ‘B’, ‘C’ and ‘D’, when placed in solution together, are designed so that A binds only to B, and C binds only to D. Each unit does not bind to itself, nor to either of the other two units to which binding is not intended. For example, A binds to B, but not to A, C, or D. Each unit contains an array of four hydrogen-bonds for strong binding to its partner, is designed to be as rigid as possible, as non-tautomeric as possible, and utilises a staggered non-symmetrical architecture. Of the four intended compounds, three were successfully synthesised (A, B and D). Units B and D were soluble in CDCl3, but Unit A was not. Therefore, the design and synthesis of Unit A was amended, and two variants of Unit A that are both soluble in CDCl3 were successfully synthesised. 1H NMR binding experiments were performed between Unit B and each of the two variants of Unit A. Their binding behaviour was described. A binding constant could not be calculated because the units did not bind in a 1:1 fashion.
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Kang, G. S. "Applications of boron chemistry to organic synthesis." Thesis, Swansea University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.637757.
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Chapter 1 deals with an investigation into the synthesis of α-aminoboronic acids and their attempted incorporation into targeted peptides. This approach, developed by Matteson, is the only methodology for the preparation of α-aminoboronates. Chapter 2 deals with an alternative route, developed by the author, to the synthesis of α-aminoboronates; an approach which is based upon the hydroboration of a nitrogen-substituted carbon-carbon double bond with a range of achiral and chiral dialkylboranes of varying steric requirement. Chapter 3 introduces the subject of boron-stabilised carbanions, with a discussion of structure, stabilisation, methods for their preparation and their application to general organic synthesis. Chapter 4 discusses methods for the production of less bulky boron stabilised carbanions derived from B-alkyl-9-borabicyclo[3.3.1]nonane by utilising a range of hindered bases. In addition, this chapter deals with the development of an alternative route to the generation of boron-stabilised carbanions via the use of gem-dimetallic compounds and their reactions with a range of enolisable and non-enolisable ketones. Chapter 5 reports on the use of alkylditripylhydroborates, a novel class of highly hindered reducing agents and specifically on the use of lithium ethylditripylhydroborate as a reagent for the reduction of a range of organic compounds containing representative functional groups. The catalytic properties of the hydroborate in the reduction of haloalkanes in the presence of metal hydride are also discussed.
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Tuckett, Mark William. "Applications of zirconium chemistry to organic synthesis." Thesis, University of Southampton, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310484.
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Spensley, C. R. C. "Some selective studies in synthetic organic chemistry." Thesis, University of Oxford, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.371583.
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Hetherington, Peter. "Organic synthesis with bromonitromethane." Thesis, Queen's University Belfast, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317552.
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Sarkar, Achintya Kumar. "Allylsilanes in organic synthesis." Thesis, University of Cambridge, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292242.
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Robinson-Surry, Julia M. (Julia Mae). "Pericyclic reactions in organic synthesis." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/65273.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2011.Page 147 missing. Cataloged from PDF version of thesis.
Includes bibliographical references.
Part I of this thesis describes a formal, metal-free, [2 + 2 + 2] cycloaddition strategy based on a cascade of two pericyclic processes. An intramolecular propargylic ene reaction of a 1,6-diyne is used to generate a vinylallene, which then reacts in an inter- or intramolecular Diels-Alder reaction with an alkenyl or alkynyl dienophile. Reactions involving unsymmetrical alkenyl and alkynyl dienophiles proceed with good to excellent regioselectivity, and endo products are formed exclusively. The mechanism of several earlier fully intramolecular related transformations have been shown to involve an analogous process rather than the diradicalmediated pathways proposed previously. Part II of this thesis describes a [4 + 4] annulation strategy involving the intramolecular [4 + 2] cycloaddition of conjugated enynes with activated cyclobutene derivatives to access intermediates containing bicyclo[4.2.0]-2,4-octadiene moieties that then undergo electrocyclic ring opening reactions to provide 1,3,5-cyclooctatrienes. Five novel cyclooctatrienes have been prepared using this method. Part III of this thesis describes the use of supercritical carbon dioxide as an environmentally friendly alternative to conventional solvents for the synthesis of a variety of carboxylic amides. The addition of amines to ketenes generated in situ via the retro-ene reaction of alkynyl ethers provides amides in good yield, in many cases with ethylene as the only byproduct of the reaction. With the exception of primary, unbranched amines, potential side reactions involving addition of the amines to carbon dioxide are not competitive with the desired C-N bond-forming reaction. The amide synthesis is applicable to the preparation of p-hydroxy and P-amino amide derivatives, as well as amides bearing isolated carbon-carbon double bonds.
by Julia M. Robinson-Surry.
Ph.D.
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Guenther, Elizabeth L. "Total Synthesis: A Crowning Achievement in Organic Chemistry." Thesis, Boston College, 2011. http://hdl.handle.net/2345/bc-ir:102073.
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Thesis advisor: Marc SnapperDiscoveries in organic chemistry have had profound impacts in many disciplines of science through the past century. Within the field of organic chemistry, research in total synthesis of natural products has provided a means of developing and advancing the study of different types of chemistry. The discovery of novel chemical transformations, use of total synthesis products in biochemical assay studies and structural studies of natural products are just a few examples of how total synthesis has influenced modern day chemistry. Developments in drug discovery such as the syntheses of penicillin and Taxol have led to applicable use of the science to help the greater global community. Total synthesis provides a means for chemists to use creativity and ingenuity to further develop knowledge of bioorganic compounds and to develop novel chemical transformations useful in medicinal chemistry. Within this paper, total synthesis will be illustrated as the most crowning achievement of modern day organic chemistry based on the earliest total syntheses, modern day total syntheses, the development of novel chemical reactions and its applicability to chemical biology research
Thesis (BS) — Boston College, 2011
Submitted to: Boston College. College of Arts and Sciences
Discipline: College Honors Program
Discipline: Chemistry
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Källström, Jan Eddy Adolf. "Synthesis studies towards daphlongeranine B." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:638685a8-da64-488b-b65d-ba9a2111d4fb.
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This thesis describes the development of a synthetic route towards daphlongeranine B, an alkaloid isolated from the fruits of Daphniphyllum longeracemosum, by utilising an intramolecular Michael addition to form its unique tricyclic core. Chapter 1 gives a general introduction to the family of Daphniphyllum alkaloids together with some recent examples, from the literature, illustrating some synthetic attempts towards structurally similar alkaloids. This chapter also features our retrosynthetic analysis of daphlongeranine B. Chapter 2 details the synthesis of the model spirocyclic enone 72 which was the vital building block needed to investigate the key intramolecular Michael addition. This key reaction was then successfully validated and access to the unique tricyclic core 64 of daphlongeranine B was made possible. Chapter 3 expands the scope of the key intramolecular Michael addition step. This chapter first describes a synthetic route to the Î2-substituted spirocyclic enone 112 and subsequently validates the key intramolecular Michael addition step to give the tricyclic core 138 of daphlongeranine B. Chapter 4 details a synthetic route towards the spirocyclic fragment 141 by utilising a Baker's yeast reduction and a tandem addition/cyclisation reaction.
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Liu, Yifan. "Synthesis of the CDE & EFG ring systems of pectenotoxin-4." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:c531f0b3-4961-43e6-b7aa-c273df89a16f.
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This thesis explores new synthetic routes for the formation of CDE & EFG fragments of pectenotoxin-4. Chapter 1: Introduction and Previous Work: This chapter reviews the discovery and biological activities of members of the pectenotoxin family. Two previous total syntheses are discussed, and previous work regarding the synthesis of ABC, E and FG fragments within the group is introduced. Chapter 2: Synthesis of the E Ring Fragment of Pectenotoxin-4: The synthesis of the E ring fragment is discussed. Key reactions include Negishi coupling and osmium mediated oxidative cyclisation. Chapter 3: First Generation Strategy for the Synthesis of the D ring: A simple model towards the D ring core was completed using alkyne-epoxide opening strategy. The application on a more sophisticated system was tested. Chapter 4: Second Generation Strategy for the Synthesis of the D ring: Sonogashira coupling was successfully tested as key step to unite two coupling partners; and further functionalisation towards the D ring skeleton was studied. Chapter 5: Third Generation Strategy for the Synthesis of the D ring: The new strategy including a Lewis acid assisted coupling and mercury mediated hydration of alkyne sequence was completed on a simple model. The application on a more sophisticated system was tested. Chapter 6: Synthesis of EFG Fragment of Pectenotoxin-4: Key Julia-Kocienski olefination between E ring fragment and FG ring fragment was examined. The further functionalisation of the resulting coupling product towards EFG fragment was finished. Chapter 7: Experimental: Full experimental procedures and characterisation of compounds are reported.
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Arif, Tanzeel. "Studies towards the stereoselective synthesis of alkenes." Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:7c1fffe2-1bf5-4c8c-bfb7-d46dd4a68342.
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The work presented in this thesis mainly describes the development of new reactions of β-lithiooxyphosphonium ylides to access stereodefined substituted alkenes in a highly convergent fashion. Firstly, β-lithiooxy ylides prepared from aldehydes and phosphonium ylides were shown to react with halogen electrophiles to provide a highly stereoselective route to E-alkenyl bromides and iodides. This methodology was successfully applied to the first total synthesis of naturally occurring (5E,9Z)-6-bromohexadeca-5,9-dienoic acid. Secondly, an experimentally straightforward method was developed for the stereocontrolled formation of trisubstituted Z-allylic esters by in situ trapping of β-lithiooxyphosphonium ylides with readily available halomethyl esters. The synthetic utility of this methodology was demonstrated with the synthesis of plaunotol [(2Z,6E)-2-((E)-4,8-dimethylnona-3,7-dien-1-yl)-6-methylocta-2,6-diene-1,8-diol] and the first asymmetric synthesis of the naturally occurring geranylgeraniol-derived diterpene (6S,7R,Z)-7-hydroxy-2-((E)-6-hydroxy-4-methylhex-4-enylidene)-6,10-dimethylundec-9-enyl acetate. Furthermore, the chemistry of β-lithiooxyphosphonium ylides was expanded to access synthetically useful disubstituted Z-allylic esters. The synthetic utility of Z-allylic esters was also demonstrated in a versatile and diastereoselective Ireland-Claisen rearrangement to access γ,δ-unsaturated acids. Finally, the synthesis of the side-chain of the 6,7-dideoxysqualestatin H5 was also investigated. It was demonstrated that the side-chain of 6,7-dideoxysqualestatin H5 could be accessed by a convergent and stereoselective organozinc-based strategy.
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O'Riordan, Timothy Jeremiah Cornelius. "Synthesis of the pyrrolidinone core of oxazolomycin A." Thesis, University of Oxford, 2009. http://ora.ox.ac.uk/objects/uuid:298746d3-69df-47b9-8a83-7949df1c94dc.
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This thesis describes the development of synthetic strategies towards the densely functionalised pyrrolidinone core of the polyene β-lactone-γ-lactam antibiotic oxazolomycin A. Chapter 1 The oxazolomycins The oxazolomycins, a unique class of biologically active molecules containing a spiro-fused β-lactone-γ-lactam ring system are introduced. The isolation, structural elucidation and biological properties of the oxazolomycins as well as those of the structurally related inthomycins are reviewed. Chapter 2 Previous syntheses The two total syntheses of neooxazolomycin and the synthetic approaches to the pyrrolidinone core of oxazolomycin A and KSM-2690 B are evaluated. Chapter 3 Project aims An outline of the synthetic strategy employed in this project and details of the novel retrosynthesis of the pyrrolidinone core of oxazolomycin A are discussed. Chapter 4 Synthetic studies towards the pyrrolidinone core of oxazolomycin A The synthetic studies carried out towards the pyrrolidinone core of oxazolomycin A are described in detail. The preparation of an advanced intermediate containing the five chiral centres, four of which are contiguous, was achieved in twenty steps as a single diastereomer and as a single enantiomer. Chapter 5 Synthetic studies towards the middle fragment of oxazolomycin A A novel synthetic approach to the diene fragment contained in oxazolomycin A is reported. The formal synthesis of a dienyl iodide, in four fewer steps than previously reported was accomplished. Chapter 6 Conclusions and future work A summary of the synthetic work reported in this thesis and proposals for future study are presented. Chapter 7 Experimental Full experimental procedures and characterisation of compounds are reported. Chapter 8 References A complete list of citations employed in the previous seven chapters is provided.
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Nimkar, Sandeep Krishnaji. "Studies in asymmetric synthesis: Development of new synthetic methods for syntheses of natural products." Diss., The University of Arizona, 1993. http://hdl.handle.net/10150/186538.
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The research, to be discussed in three chapters, involves the development of new synthetic methods which are applicable to the total synthesis of many natural products. Chapter 1: As a part of a program to synthesize new auxiliary agents for asymmetric synthesis, we have prepared a structurally rigid acetal from norbornene in three chemical steps. This enantiomerically pure acetal has been used for resolution of racemic α-hydroxy esters and might be applied as a chiral auxiliary for diastereoselective reactions. Chapter 2: The Calicheamicin and Esperamicin antibiotics have shown remarkable biological activity as site-specific cleaving agents of double stranded DNA. The oligosaccharide portion of these molecules plays an important role in the site specificity. We have developed synthetic methodologies that allow synthesis of the deoxyaminosugar components of these antibiotics and can be extended to synthesize unnatural amino sugars for structure-activity studies. Chapter 3: Enantiomerically pure cyclopropyl ketones, which are available via chiral ketals, are very useful for syntheses and diastereoselective manipulations of common and large rings. This method has been extended to introduce up to four contiguous chiral centers in a common ring. This extension could be useful for the syntheses of complex natural products.
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Winberg, Karl Johan. "Carborane Derivatives for Nuclide Therapy and Imaging : Synthesis and Radio-labelling." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ-bibl. [distributör], 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-3561.
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Howard, Joseph. "Exploring mechanochemistry for organic synthesis." Thesis, Cardiff University, 2018. http://orca.cf.ac.uk/116636/.
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This thesis describes an investigation into performing organic synthesis under mechanochemical conditions. Procedures were developed for the selective mono- and difluorination of 1,3-dicarbonyls and the one-pot, two-step synthesis of fluorinated pyrazolones under ball milling. Attempts to perform a two-step mechanochemical synthesis of difluoromethylthioethers led to exciting results demonstrating that ball milling can lead to alternative reactions occurring. Finally, some initial results into the generation and reaction of organomanganese reagents under mechanochemical conditions are reported. Initial investigations into the use of mechanochemistry for organic synthesis focused on the mechanochemical formation of the C-F bond, with a particular focus on differences in selectivities observed under different milling conditions. It was found that electrophilic fluorination of 1,3-dicarbonyls could be achieved under ball milling conditions using Selectfluor. The selectivity of this process could be significantly enhanced using Liquid Assisted Grinding with acetonitrile as an additive. The possible causes of this observed change in selectivity were investigated. Further work developing a one-pot, two-step mechanochemical process was performed. A procedure for the synthesis of fluorinated pyrazolones was developed and some of the key considerations when attempting one-pot mechanochemical procedures were established by a careful optimisation. Conditions compatible with both the heterocycle formation step and the fluorination step were found and a range of fluorinated pyrazolones successfully synthesised by this method. It was observed that mechanochemistry could be used to alter the chemoselectivity of a reaction while attempting the synthesis of difluoromethylthioethers. After detailed study, a hypothesis to the origin of this alteration in selectivity was proposed. Finally, some initial results into the use of mechanochemical methods to activate manganese metal for applications in synthesis are presented.
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Fiumana, Andrea. "Indole radicals in organic synthesis." Thesis, Kingston University, 2002. http://eprints.kingston.ac.uk/20697/.
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The generation and subsequent reactions of radicals formed from aryl halides is now well documented and several natural product syntheses based on aryl radical cyclisation have been reported. However, little work has been published on the generation of radicals in heteroaromatic systems such as indole. Radical reactions, particularly those involving aryl and indole radicals are reviewed. The generation of 2-indolyl radicals and their addition to a variety of radical acceptors to prepare 2-substituted indoles is presented. The addition to aromatic solvent is also reported as an alternative route to the palladium catalysed cross-coupling method for the synthesis of 2-arylindoles. Annulation of indole via indole radicals is also explored. A short synthesis of fused [1,2-a]indoles via radical addition to the benzene ring followed by rearomatisation is described. One example undergoes an unusual radical translocation/addition reaction. The mitomycin skeleton and the mode of biological action of mitomycin are briefly discussed. A new synthetic strategy is described involving a translocation/cyclisation of N-substituted 2-indolyl radicals. An attempted asymmetric synthesis of aziridinomitosenes is described. An investigation of indole C2-C3 radical cyclisation as a route to cyc1opentano[b ]indole alkaloids is described. The effects of substituents on the radical acceptor are explored. Full experimental and spectroscopy data is given for all new and key intermediary compounds.
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Wild, Mark. "Synthetic studies towards the synthesis of spongistatin 1." Thesis, Bangor University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310863.
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Turvill, Michael W. "The synthesis of natural and synthetic colouring materials." Thesis, University of Nottingham, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280103.
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Wang, Shouming. "Synthetic methodology and synthesis using #alpha#,#beta#-epoxyaldehydes." Thesis, University of Salford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328053.
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Thom, Catriona. "Synthetic methods directed towards the synthesis of rapamycin." Thesis, University of Southampton, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241117.
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Kalek, Marcin. "Synthesis of C(sp2)-P bonds by palladium-catalyzed reactions : Mechanistic investigations and synthetic studies." Doctoral thesis, Stockholms universitet, Institutionen för organisk kemi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-56467.
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This thesis focuses on synthetic and mechanistic aspects of palladium-catalyzed C(sp2)-P bond-forming reactions, with the aim to develop mild and efficient methods for the synthesis of biologically active phosphorus compounds, e.g. DNA analogs. The first part of the thesis is devoted to detailed mechanistic investigations of the palladium-catalyzed C-P cross-coupling reaction, in order to fully understand the underlying chemistry and by rational design of the reaction conditions, improve the overall efficiency of the process and broaden its applicability. In particular influence of palladium coordination by different anions on the rate of ligand substitution and reductive elimination steps of the reaction was studied. It was found that coordination of acetate ion results in unprecedented acceleration of both of the mechanistic steps, what leads to remarkable shortening of the overall reaction times. In-depth kinetic investigations enabled to ascribe the observed effects to ability of the acetate ion to act as a bidentate ligand for palladium. This causes considerable alternation of the reaction mechanism, comparing to the reaction involving halide-containing complexes, and results in significant rate increase. Based on the above mechanistic studies an efficient method for the synthesis of arylphosphonates, using substoichiometric amounts of inorganic acetate additive and reduced amount of catalyst, was developed. In the next part of the thesis, efforts to further enhance the palladium-catalyzed cross-coupling efficiency by using a microwave-assisted synthesis are described. These explorations resulted in a successful development of two protocols, one for a cross-coupling of H-phosphonates and the other for H,H-phosphinates, under the microwave heating conditions. Application of this energy source resulted in extremely short reaction times, measured in minutes. The final chapter of this thesis deals with studies on palladium-catalyzed SN2’ propargylic substitution reaction with phosphorus nucleophiles, which leads to allene products. Efficient procedure for the synthesis of allenylphosphonates and related compounds was developed. The method enables full control of stereochemistry in the allene moiety and at the asymmetric phosphorus center. Some conclusions on the mechanism of the reaction were also drawn.At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 7: In press.
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Gooneratne, Samantha Indira. "Polymer supports for solid-phase organic chemistry reactors." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609539.
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Ibbett, Ashley James. "Synthesis and host-guest chemistry of organic polycations." Thesis, University College London (University of London), 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264211.
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Jackson, Catherine Mary. "Analysis and synthesis in nineteenth-century organic chemistry." Thesis, University College London (University of London), 2009. http://discovery.ucl.ac.uk/10048633/.
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This dissertation examines the development of synthetic organic chemistry in academic laboratories in nineteenth-century Germany. By studying the laboratory practice of chemists including Justus Liebig, August Hofmann and Albert Ladenburg, I show that early synthetical experiments were undertaken with primarily analytical goals, and that construction did not become the dominant purpose of organic synthesis until around 1880. I argue that successful constructive synthesis depended on a new glassware based practice whose unprecedented scale and intrinsic danger drove the construction of purpose-built chemical laboratories from the 1860s onwards. I therefore propose both a revised historiography of nineteenth-century organic chemistry, and a reinterpretation of the institutional revolution in late-nineteenth century physical sciences. I re-examine Liebig's motives for tackling the analysis of alkaloids, using his 1830 laboratory notebook to reconstruct Liebig's experimental approach to this technically demanding task, including his development of a new apparatus for the determination of carbon — the Kaliapparat. I show that incorporating analysis using the Kaliapparat into a reliable, pedagogically stable method involved the labour of the entire Giessen research school. Liebig, his students and assistants produced new chemical knowledge from indeterminate analytical data by a combination of theoretical and practical expertise acquired through disciplined laboratory training, and I argue that a similar philosophy of practice was equally essential in synthetic organic chemistry. Synthesis made chemical identity a focus of chemists' practical concern and I demonstrate that purity, transformation and identity were central to Hofmann's constitutional analysis and Ladenburg's eventual synthesis of the hemlock alkaloid coniine. I explore the origins of what I term the glassware revolution, and its role in resolving the question of chemical identity. Finally, I show how Ladenburg's synthesis depended on glass and glassblowing, and I argue that this new chemical practice both produced and depended on highly organised, specialised laboratory spaces.
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Kimani, Flora, and Flora Kimani. "Triazabutadiene Chemistry in Organic Synthesis and Chemical Biology." Diss., The University of Arizona, 2016. http://hdl.handle.net/10150/620986.
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Triazabutadienes are nitrogen containing compounds with interesting acid-responsive behavior. These compounds are relatively stable, but once activated by an electrophile, for example through protonation, fall apart to yield diazonium and imine compounds. In general, diazonium compounds are unstable and require harsh methods of synthesis. Therefore, the use of triazabutadiene compounds as precursors to diazonium compounds, allows for a mild and more controlled access to this reactive moiety. This opens up diazonium chemistry to more complex chemical biology applications, as well as in the development of applications in organic synthesis. In an effort to design triazabutadiene systems that release diazonium compounds in physiological conditions, water-soluble imidazolium-based triazabutadienes were synthesized by coupling N-heterocycle imidazolium carbenes to aryl azides. These compounds were shown to have pH-dependent reactivity, generating aryl diazonium salts in buffered solutions ranging from pH 4-7. This reactivity made these compounds one of the mildest ways of generating aryl diazonium salts in aqueous solutions. Initial stability and reactivity studies were performed by NMR, and by altering the sterics of the imidazolium core and the electronics of the phenyl group. It was determined that the rate and stability were influenced by the sterics and electronics of the scaffold. Electron withdrawing substituents on the phenyl and steric bulk on the imidazole core resulted in stable triazabutadienes, with the opposite being observed for the electron donating substituents on the phenyl and small substituents on the imidazole. Water-soluble triazabutadienes were synthesized to be further utilized as chemical biology probes. In organic solvents, the triazabutadienes reacted with resorcinol, an electron-rich phenyl group to form stable azo compounds. In more physiologically relevant conditions, the triazabutadiene compound was stirred in a pH 6 phosphate/citric buffer solution with a tyrosine analogue and an azo adduct was isolated. This indicated it was possible to target tyrosine residues with a triazabutadiene delivered aryl diazonium through the formation of azo bonds that could be cleaved under mild reducing conditions using sodium dithionite. In addition, the triazabutadiene compounds were found to undergo light-induced isomerism generating the Z isomer in solution upon irradiation. The Z isomer was observed to be more reactive, and would degrade even in basic solutions when irradiated with 350 nm light. This light responsiveness was utilized to enhance the reactivity of triazabutadiene attached onto protein and viral surfaces, allowing the generation and capture of aryl diazonium salts by electron rich aryl-fluorophore conjugates as well as antibody proteins in the case of the virus. Alkyl triazabutadiene compounds were synthesized by coupling N-heterocycle carbenes onto alkyl azides. These compounds were then shown to be capable of delivering alkyl diazonium compounds to carboxylic acids for esterification. This method diversifies esterification from only methyl substituents, as is the case with diazomethane and TMS-diazomethane, to larger more diverse alkyl groups. In conclusion, this work shows that the triazabutadiene compounds have interesting activity that will be vital in the development of novel probes for the study of biological process, as well as the development of reagents for chemical synthesis.
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Patel, Hasmitta. "Organochromium complexes in organic synthesis." Thesis, Heriot-Watt University, 1988. http://hdl.handle.net/10399/995.
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Morris, M. D. "Organoiron complexes in organic synthesis." Thesis, University of Southampton, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370348.
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Rutherford, David Thomas. "Heterobimetallic complexes in organic synthesis." Thesis, Loughborough University, 2001. https://dspace.lboro.ac.uk/2134/35604.
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Heterobimetallic cobalt-molybdenum-cyclo-penta-dienyl-alkynyl-penta-carbonyl complexes have been demonstrated to act as efficient substrates for the Pauson-Khand cycloaddition under appropriate conditions. The inherent chirality present in the heterobimetallic core has been shown to efficiently promote a stereoselective variant of the Pauson-Khand reaction. The unique mode of stereoinduction in contrast to existing methodology has enabled the first stereospecific Pauson-Khand reaction to be realised in the absence of an external source of chirality. The scope of heterobimetallic alkyne complexes for more general asymmetric organic synthetic transformations has been briefly addressed. The heterobimetallic core has been shown to promote moderate to high levels of stereocontrol on addition of nucleophiles to remote centres of complexed propargylic aldehydes. In light of the potential use of heterobimetallic complexes in organic synthesis a new robust and experimentally facile route for complex generation has been developed. Employing this route heterobimetallic complexes cim be rapidly and routinely generated avoiding specialist techniques or apparatus. Chapter 1 provides a brief overview of the Pauson-Khand reaction and developments in this field. Chapter 2 highlights our work utilising hereobimetallic alkyne complexes as substrates in the Pauson-Khand reaction, their use in more general synthetic transformations and the development of a facile but robust route for their synthesis. Chapter 3 provides experimental data for our studies.
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Castle, Grant Hilliard. "Functionalised dispiroketals in organic synthesis." Thesis, University of Cambridge, 1994. https://www.repository.cam.ac.uk/handle/1810/272782.
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Kim, Byeongmoon 1957. "Asymmetric organic synthesis using organoboron compounds." Thesis, Massachusetts Institute of Technology, 1987. http://hdl.handle.net/1721.1/14679.
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Esfandiarfard, Keyhan. "Novel Organophosphorus Compounds for Materials and Organic Synthesis." Doctoral thesis, Uppsala universitet, Molekylär biomimetik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-328295.
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This thesis is devoted to the development of new organophosphorus compounds for potential uses in material science and as reagents in Organic Chemistry. Organophosphorus compounds in a single molecule or organic electronics context are appealing as the phosphorous centers perturb the electronic properties of the π-conjugated systems while at the same time provide synthetic handles for subsequent synthetic modifications. As such, new synthetic methodology to such compounds and the exploration of new building blocks is of considerable interest. In a different study, novel organophosphorus compounds are synthesized and shown to promote a reaction in Organic Chemistry that has previously not been possible, i.e. the stereoselective reductive coupling of aldehydes to alkenes. Such developments enlarge the toolkit of reactions that are available to Organic Chemists, and may impact the synthetic routes to pharmaceuticals and other important commodity chemicals. A general introduction of the key structural unit of this thesis, phosphaalkenes, is given in the first chapter. The synthesis, reactivity, properties and applications of these P=C double bond containing compounds are highlighted. The Wittig reaction and its variations as well as the phosphorus analogues that produce phosphaalkenes are outlined in detail. The second chapter is dedicated to the synthesis of a precursor that is used for the preparation of novel π-conjugated, organophosphorus compounds. C,C-Dibromophosphaalkenes are prepared and the halide substituents are used for the selective introduction of acetylene units. Besides the phosphaalkenes, the successful syntheses of two new diphosphenes is presented, indicating a broad applicability of the precursors. The third chapter is dedicated to the isolation of a metal-free phosphanylphosphonate that transforms aldehydes quantitatively to their corresponding E-phosphaalkenes in a transition metal-free phospha-HWE (Horner-Wadsworth-Emmons) reaction. The reaction benefits from mild conditions, high E-stereoselectivity, and a broad substrate scope. In the last chapter, a novel method for the reductive coupling of aldehydes to olefins is introduced. The reaction, which is a vast improvement over the McMurry coupling, allows for the selective synthesis of symmetrical and most importantly unsymmetrical E-alkenes. The phosphanylphosphonate mentioned above is the reagent that facilitates the coupling of the aldehydes via a phosphaalkene intermediate. This one-pot reaction benefits from mild conditions, good conversions, and high E-stereoselectivity. In summary, the thesis presents novel aspects of organophosphorus chemistry. These include the preparations and exploration of interesting precursors for the construction of π-conjugated organophosphorus compounds, and the use of organophosphorus reagents for unprecedented transformations in Organic Chemistry.
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Brown, David Alexander. "Synthesis and derivative chemistry of icosahedral carboranes." Thesis, Durham University, 1985. http://etheses.dur.ac.uk/7140/.
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A series of icosahedral carboranes including, ortho-1-methyl-ortho- and 1-phenyl-ortho-carborane were prepared from decaborane and the appropriately substituted acetylenes. An investigation of the preparative route to ortho-carborane showed that improvements could be made to the literature method employed. Meta-carborane was obtained in high yields by the thermal isomerization of ortho-carborane. The structurally-characterised compounds Li(C(_2)B(_10)H(_10)Me) (PMDETA) and Mg(C(_2)B(_10)H(_10)Me)(_2)(C(_4)H(_8)O(_2))(_2). C(_2) H(_8) contain unprecedented examples of group I and II metals covalently bonded to six-co-ordinate carbon atoms. Features of the structures are compared with those of other organolithium and organo-magnesiura compounds and used to calculate the cone angles and steric requirements of icosahedral carboranyl and methyl-carboranyl ligands attached to metal atoms of various sizes. Series of, carboranyl ketones of formulae RθCOR' and (Rθ)(-2)CO (where R = H, Me, Ph and R' = Ph), carboranyl amides of formulae RNHCOθCONHR and RNHCOθ'CONHR (where R = Ph, Me,(^t) Bu) and boranyl-carboranes of formulae RθBR'(_2) and (Rθ')(_2)BR'(where R = H, Me and R' = Ph), were synthesized and an investigation carried out to assess their relative stabilities to hydrolytic degradation. These studies revealed interesting trends within each series. A series of C-hydroxy-derivatives including MeθOH, PhθOH, HθOH, Hθ'OH and H0θ0H were successfully prepared by the reactions of the mono- or dilithio-carboranes with oxygen or with benzoyl peroxide. All of the hydroxy- carboranes with the exception of H0θ0H were crystalline solids. A number of tertiary ammonium salts of the ortho-carboranyl-C-hydroxy derivatives were prepared in high yields. No salts of the meta-derivative, Hθ’OH were obtained. All of the salts were white crystalline solids, their infra-red, (^1)H, (^11)B and COSY n.m.r. spectra showing interesting and significant differences to those of their corresponding hydroxy-derivatives, many of these differences, presumably attributable to increases in the C-0 bond order and an increase in electron density within the cage.The previously unreported MeθOSiMe(_3) was prepared by the reaction of MeθOHNEt. with Me(_3)SiCl and isolated as a stable, crystalline solid.
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Ewin, Richard Andrew. "Applications of radical chemistry to alkaloid synthesis." Thesis, King's College London (University of London), 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261811.
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Smith, N. M. "Synthesis and chemistry of novel bridged polyamines." Thesis, University of Southampton, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.373183.
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Williamson, Emily R. "Organic Synthesis of Kaurenoic Acid." Kent State University Honors College / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ksuhonors158832460424579.
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Bodé, Nicholas. "Exploring Undergraduate Organic Chemistry Students’ Strategies and Reasoning when Solving Organic Synthesis Problems." Thesis, Université d'Ottawa / University of Ottawa, 2018. http://hdl.handle.net/10393/38182.
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Organic synthesis problems are a common assessment tool in organic chemistry courses, as they give instructors the opportunity to determine students’ ability to integrate and apply their knowledge of reactions and skills learned in the course. However, students often tend to be unsuccessful in solving them, even if they appear to have a strong grasp on other course material. We hypothesized that part of the reasoning behind this issue is because it can be challenging to integrate learning activities into the curriculum that give students the opportunity to apply their knowledge to synthetic problem solving, while still giving students the opportunity to master the underlying concepts (knowledge of organic reactions and reaction mechanisms). In addition, there is a gap in our understanding of the mental models students construct while solving these problems, as there is no evidence that they approach these problems in the same manner that experts do (i.e., retrosynthetic analysis). The research described in this thesis was performed to address these issues in two ways. First, we designed learning activities for students that were meant to help them develop more systematic approaches (whose benefits are supported by evidence) to solving synthesis problems, and determining if those learning activities could produce significant learning gains. The learning activities we designed were made available to students through out-of-class learning workshops, where learning gains were primarily measured through the analysis of students’ synthetic problem-solving abilities, assessed immediately before and after the workshops. Second, we sought to obtain a better understanding of students’ mental models when solving synthesis problems; specifically, we wanted to see if they had well-defined strategies for approaching these problems, and if they had a canonical understanding of how these strategies were meant to be applied. To do so, we invited students to participate in semi-structured think-aloud interviews, where participants were asked to solve synthesis problems. We investigated both of these topics using a constructivist paradigm for learning, which states that knowledge is constructed in the mind of the learner rather than passively imparted. The process of knowledge construction is heavily influenced by the prior knowledge and experiences of the learner, and meaningful understanding of new knowledge is unlikely to occur if new knowledge cannot be accommodated by existing knowledge structures. Results from these studies indicated that the workshop-style intervention did not have any effect on students’ ability to successfully solve synthesis problems, but we did observe proficiency in the ability to use expert-like strategies, suggesting that more practice over time could lead to the ability to solve synthesis problems more effectively. Our analysis of the interview data showed that some students can proficiently use strategies in situations that are familiar to them, but do not appear to be able to apply those strategies to predict outcomes in unfamiliar situations; further, we observed a strong reliance on the use of reasoning that was based on memorized rules. Future work could further explore the mental models that students construct for solving synthesis problems; we recommend the incorporation of specific instruction on the use of synthesis problem-solving strategies, and research could explore the relationship between students’ abilities, and how synthesis is taught, practiced, and assessed in the organic chemistry curriculum.
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Pearson, David James. "Synthetic studies towards the total synthesis of popolohuanone E." Thesis, University of Sheffield, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267117.
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Connolly, Matthew James. "Selective routes to substituted dihydropyridones." Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:2e670c3f-e928-46c5-a1db-28bc1a6609e6.
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Introduction: The introduction provides a survey of the natural product and pharmaceutical targets accessible from dihydropyridines and dihydropyridones as well as an overview of previous work carried out towards the synthesis of these valuable intermediates. The mechanism, scope and limitations of the various approaches are covered, along with the goals of this project. Results and Discussion: A Regioselective Route to Dihydropyridones. The regioselective addition of nucleophiles to a range of disubstituted pyridinium salts has been achieved, with selectivity determined by hard/soft factors. Certain nucleophiles can be added with complete regioselectivity to either C-2 or C-6 of these salts, depending on the conditions employed. Addition at C-2 allows the generation of a quaternary centre in high yield. The conditions discovered can be applied to pyridinium salts with different substitution patterns and an effective procedure has been developed for the removal of the nitrogen protecting group post reduction. The Preparation of Enantiopure Dihydropyridones.After unsuccessful attempts to find a reagent-controlled asymmetric synthesis of dihydropyridones, a highly diastereoselective and non-chiral auxiliary based substrate-controlled procedure has been developed. By prompting an intramolecular hydride migration from a secondary silyl ether onto the pyridinium core, the corresponding dihydropyridones are available in high yield, with the diastereoselectivity being controlled by the minimization of 1,3-allylic strain between the N-allyl group and the hydride-bearing side chain. Thus, an enantiopure pyridyl alcohol may be converted to the corresponding dihydropyridone without loss of enantiomeric purity. Furthermore, the dihydropyridones can be easily converted to complex bicyclic systems via a ring closing metathesis reaction. Experimental: Full experimental procedures and spectroscopic characterization of compounds are provided.
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Nguyen, Thi-Ngoc Dieu. "Allylsilanes in organic synthesis homoallylic alcohol synthesis and electrophilic alkylation." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=60726.
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The chelating effect on regio- and stereochemical control of the homoallyl alcohol synthesis and electrophilic substitution of allylsilane was studied, using 2,2-dimethyl-1-$ {$1- ((S)-2-(2-methoxyethoxy)methyl) pyrrolidinyl$ }$-2-sila-4-pentene (S1) and 2,2-Dimethyl-1-$ {$1- ((S)-2-hydroxymethyl) pyrrolidinyl$ !$-2-sila-4-pentene (S2), with S1 synthesized from L-Prolinol.The synthesis of homoallyl alcohol was carried out by allyl transformation from S1 and S2 to a Lewis acid activated aldehyde. Chelation between the allylsilyl ligand and the Lewis acid:aldehyde complex was found to favor the cyclic syn-clinal over the acyclic anti-periplanar transition state, in the asymmetric synthesis of the alcohol 1-dodecen-4-ol (P1). The bulky, remote and weak chelating ligand resulted in only modest selectivity and average chemical yield.
Regio- and stereochemical control of the electrophilic alkylation of allylsilanes S1 were achieved due to chelating effect that favored $ alpha$-alkylation. The chiral chelating ligand also resulted in enhanced stereochemical control electrophilic alkylation. Steric effect, due to a large electrophile, and solvent effect that causes disruption of the chelated complex, decrease $ alpha$-selectivity.
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Wu, Boshen. "Synthesis of taurospongin A and other biologically active natural products." Thesis, University of Oxford, 2017. http://ora.ox.ac.uk/objects/uuid:37a34bc4-efb4-4a6b-9d44-a3ad1c8ae0be.
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This thesis firstly describes a synthesis of the natural product taurospongin A, a potent DNA polymerase beta inhibitor. Sharpless asymmetric dihydroxylation on olefin E-1.60 followed by selective deoxygenation at C(2) via Barton‒McCombie reaction delivers the desired C(1)–C(10) carboxylic acid core. Subsequent esterification of the C(1)–C(10) fragment with C(1′)–C(25′) fatty acid furnishes the natural product in 13.5% yield. The structure of an unnamed natural product 2.14 isolated in 1974 is proven to be misassigned by previous studies within the Robertson group. As described in this thesis, two proposed structures A and B are obtained via total synthesis in order to reveal the identity of the natural product. A synthesis of key intermediate spirocycles 2.148 and 2.158 with desired trans- diol moiety is described by a dihydroxylation reaction on an electron deficient gamma-keto unsaturated acid with subsequent spirocyclisation reaction. Finally, methodology for generating high-value synthetic intermediates by an asymmetric, one-pot enzymatic di/polycarbonyl reduction is described. The concept of such methodology is first proven by the synthesis of (3R)-hydroxybutyl (3R)-hydroxybutanoate 3.20. This thesis then describes substrate scope studies and corresponding stereochemical proof to provide more information about this methodology.
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Hawkins, Alison. "Studies towards the total synthesis of manzamine A." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:0ca64b5d-bc7c-4624-b9c2-4b5f7b6967e3.
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This thesis describes studies towards the total synthesis of manzamine A (9), a marine alkaloid. Two routes are presented. The first route applied a novel palladium-catalysed arylative allene spirocyclisation cascade to the synthesis of manzamine A (9). In the first generation, a short route was developed to access the tricyclic ACE core 263a in only nine steps. The second generation applied the palladium-catalysed cascade to a similar system which utilised non-terminal allene pro-nucleophile 450 in an attempt to access a homologated derivative of the ACE core. The second route relied on a diastereoselective Michael addition between nitro-olefin 473 and 8,5-fused ring system 146 comprising rings C and E of manzamine A (9). Further elaboration of the Michael addition product enabled the synthesis of tetracyclic ABCE core precursor 464 to be carried out and preliminary investigations into ring B formation were investigated.
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Swali, Vinay. "Synthesis of lantibiotic based templates for solid phase synthesis and combinatorial chemistry." Thesis, University of Southampton, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326748.
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