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Dissertations / Theses on the topic 'Lactams'

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Published: 4 June 2021

Last updated: 21 September 2024

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1

Betou, Marie. "Semipinacol rearrangement of cis-fused β-lactam diols into bicyclic lactams." Thesis, University of Birmingham, 2013. http://etheses.bham.ac.uk//id/eprint/4348/.

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The 6-azabicyclo[3.2.1]octane ring system is found in a wide variety of biologically active natural and non-natural products. The aim of this project is to prepare the 7,8-diketo-6-azabicyclo[3.2.1]octane structure via a semipinacol rearrangement of ring-fused β -lactams. Chapter 1 introduces the pinacol and semipinacol rearrangement, including the use of cyclic sulfites and phosphoranes, and ring expansion of β -lactams. Previous work in the Grainger group for the synthesis of lactams via tandem radical cyclisation-dithiocarbamate group transfer is also discussed. Chapter 2 describes the methodology developed for the semipinacol rearrangement of β-lactams. Access to suitable precursors for the semipinacol rearrangement is achieved through a sequence of 4-exo trig radical cyclisation, base-mediated dithiocarbamate group elimination and dihydroxylation. Formation of the 7,8-diketo-6-azabicyclo[3.2.1]octane ring system occurs through semipinacol rearrangement of the corresponding cyclic sulfites and phosphoranes. In Chapter 3, the scope and limitations of the methodology are explored. Different substituents on the nitrogen of the β-lactam, groups on the cyclohexane moiety (methyl and oxygenation) and ring sizes are investigated. An original approach to the total synthesis of peduncularine is described in Chapter 4. Synthesis of a suitably functionalised β-lactam and attempts to further transform it into the desired 7,8-diketo-6- azabicyclo[3.2.1]oct-3-ene structure are reported. Work towards the total synthesis of calyciphylline D, calyciphylline F and caldaphnidine M is described in chapter 5. Reductive amination and stereoselective reduction of piperitone are investigated. Use of a model system for the addition of nucleophiles onto thiolactams is also described.

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2

Warren, H. A. "New routes to sugar lactams, lactim ethers and cyclic amidines." Thesis, Swansea University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.639351.

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Chapter 1 introduces the biological importance of glycosidase inhibitors. The biosynthesis of N-linked glycoproteins is briefly described and the mode of action of glycosidase enzymes is discussed. Some naturally occurring amino-sugar glycosidase inhibitors are detailed. In addition certain sugar lactones, lactams and cyclic amidines which have also been shown to inhibit glycosidase enzymes are reviewed. Chapter 2 introduces the syntheses of various polyhydroxylated piperidine and pyrrolidine alkaloids and sugar lactams. In addition the formation of cyclic sugar amidines and their derivatives is discussed. Chapter 3 involves the syntheses of four novel sugar lactams. The syntheses of 4-amino-4-deoxy-D-allonolactam and 4-amino-4-deoxy-D-talonolactam via novel routes developed by the author are dealt with in detail. The preparations of the corresponding D- and L-ribono compounds by a shortening of the carbon chain are also described. Chapter 4 introduces the syntheses of the novel D-allono-, D-talono- and D-ribono- amidines from the corresponding lactam derivatives. Chapter 4 also reports on literature preparations of sugar tetrazoles and their inhibitory properties towards glycosidase enzymes. Also included is the synthesis of the novel D-talonotetrazole.

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3

Guignard, Guillaume Michel Pablo. "Open-chain building blocks from chiral lactams. Enantioselective synthesis of macrocyclic nitrogen-containing natural products." Doctoral thesis, Universitat de Barcelona, 2016. http://hdl.handle.net/10803/396650.

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1. (R)-Phenylglycinol-derived oxazolopiperidone lactams can be converted to enantiopure open-chain amino ester scaffolds by alkaline hydrolysis of the N-Boc 2-piperidones resulting from the reductive cleavage of the oxazolidine ring. 2. Lithium amidotrihydroborate (LiNH2BH3) reduction of diversely substituted (R)-phenylglycinol-derived oxazolopiperidone lactams brought about the reductive opening of both the oxazolidine and lactam rings, providing general access to structurally diverse enantiopure amino diols A bearing a variety of substitution patterns, substituents (alkyl, benzyl, aryl, protected hydroxy), and stereochemistries. 3. Reductive removal of the phenylethanol moiety present in the amino diols prepared by the above procedure, followed by treatment of the resulting primary amines with (Boc)2O provides a general synthetic entry to enantiopure N-Boc 5-aminopentanols bearing substitutents at the 2-, 3-, 4-, 2,2-, 2,3-, 2,4-, and 3,4- positions. 4. The oxidative removal of the phenylglycinol moiety of amino diols A (previously O-silylated) using the I2/aq NH3 system constitutes an excellent procedure for the straightforward preparation of enantiopure substituted 5-hydroxypentanenitrile derivatives. 5. The m-CPBA-promoted oxidative removal of the phenylglycinol moiety of amino diols A (previously O-silylated) constitutes an excellent procedure for the straightforward preparation of enantiopure substituted 5-hydroxypentanoic acid derivatives. 6. As both enantiomers of phenylglycinol are commercially available, both enantiomers of a target 5-aminopentanol, 5-hydroxypentanoic acid, and 5-hydroxypentanenitrile are accessible through the above methodology. 7. The synthetic value of the open-chain amino diols A has been demonstrated with their use as key scaffolds for the enantioselective synthesis of the Haliclona alkaloids haliclorensin C (first total synthesis), haliclorensin (total), halitulin (formal), and isohaliclorensin (formal). 8. The synthetic value of the open-chain amino diols 5-hydroxypentanoic acids, and 5-hydroxypentanenitriles prepared from (S)-phenylglycinol-derived lactams has been demonstrated with their use as key scaffolds for the synthesis of the natural macrolactam fluvirucinin B1. 9. The approach we have developed significantly expands the potential of phenylglycinol-derived d-lactams, which have been converted for the first time to enantiopure open-chain building blocks.

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4

Sheppard, L. N. "Synthesis of B-lactams." Thesis, University of Oxford, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.354855.

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5

McKenna, Jeffrey M. "Asymmetric synthesis of #beta#-lactams." Thesis, University of Oxford, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240681.

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6

Goh, Kee Chuan. "The biosynthesis of β-lactams." Thesis, University of Oxford, 1993. http://ora.ox.ac.uk/objects/uuid:24b6b29d-87cc-48f2-bd1b-bb64c663604f.

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This thesis reports the work done on two research projects which were carried out independently of each other but converge on the central theme of β-lactam biosynthesis. Chapter 1 provides an overview of biosynthesis in secondary metabolism, with special emphasis on current knowledge about the β-lactams. The first project, covered from Chapters 2 to 5, was part of our group's continuing effort to understand the structure and mechanism of Ring Expandase-Hydroxylase (REXH), an enzyme involved in the biosynthesis of cephalosporin C in Cephalosporium acremonium. REXH is a bifunctional enzyme, converting penicillin N to DAOC and thence to DAC. [diagram omitted from transcription] Chapter 3 discusses the investigation of purification protocols for native REXH and soluble recombinant REXH, as well as an improved refolding method for recombinant REXH expressed as inclusion bodies. Chapter 4 describes two new alternative substrates for REXH, viz. carba-DAOC and DAC, whilst the y-lactam analogue of penicillin N was not found to be a substrate for REXH. Chapter 5 summarises some structural investigations of REXH employing methods such as electrospray mass spectrometry, selective proteolysis and inhibition kinetics. [diagram omitted from transcription] The second project, covered from Chapters 6 to 9, represents the first biosynthetic studies on valclavam, an antifungal produced by Streptomyces antibioticus. Valclavam belongs to the family of clavams which includes clavulanic acid as its most well studied member. [diagram omitted from transcription] Chapter 7 details the development of methods for the bioassay, fermentation and isolation of valclavam. It also describes the isolation of a stable degradation fragment of valclavam which led to the revision of the structures of valclavam and Tü 1718B (another metabolite from the same organism). Chapter 8 gives an account of the whole-cell feeding experiments which strongly suggest that the primary metabolic precursors for valclavam are L-valine, L-arginine, L-methionine and glycerol. Chapter 9 reports the discovery of two enzymic activities, belonging to those of clavaminic acid synthase and proclavaminic acid amidino hydrolase, which are likely to be involved in the biosynthesis of valclavam. Together, the results of Chapters 8 and 9 point to an extensive overlap between the clavulanic acid pathway in Streptomyces clavuligerus and the valclavam pathway in Streptomyces antibioticus.

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7

Welchman, Elizabeth Victoria. "The chemistry of Î² lactams." Thesis, University of Sunderland, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.247775.

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8

Walker, Matthew David. "Diastereoselective reactions of atropisomeric lactams." Thesis, University of Nottingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.247569.

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9

Pearson, C. J. "Synthesis of aza-beta-lactams." Thesis, Imperial College London, 1985. http://hdl.handle.net/10044/1/37815.

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10

Joshi, S. N. "Diastereoselective synthesis of β-lactams." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2000. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/2271.

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11

Jayaraman, M. "Asymmetric synthesis of β-lactams." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 1994. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/2803.

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12

Srirajan, V. "Diastereoselective synthesis of β - lactams." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 1996. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/3378.

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13

Thiagarajan, K. "Studies in β-lactams synthesis." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2002. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/2853.

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14

Pérez, Bosch Maria. "Addicions conjugades a lactames bicícliques derivades del fenilglicinol: síntesi enantioselectiva de piperidines 3,4- i 3,4,5-substituïdes." Doctoral thesis, Universitat de Barcelona, 2002. http://hdl.handle.net/10803/673099.

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La adición conjugada de cianocupratos de orden inferior a las lactamas insaturadas derivadas del fenilglilcinol transcurre con buenos rendimientos y elevada selectividad facial. En aquellas que poseen un sustituyente etilo en posición contigua al carbono electrófilo del doble enlace proporciona estereoselectivamente productos con una relación cis entre el sustituyente carbonado introducido y el grupo etilo. Estos resultados pueden justificarse considerando que la conformación del anillo de piperidina se halla condicionada por la configuración de un estereocentro, independientemente de la presencia de un sustituyente etilo, y que el ataque del cianocuprato tiene lugar bajo control estereoeléctrónico proporcionando el producto de control cinético debido a la irreversibilidad de la reacción. Por otro lado, la adición de aniones estabilizados a una lactama insaturada que posee un sustituyente etilo contiguo al carbono electrófilo del doble proporciona compuestos que guardan una relación trans entre el sustituyente carbonado introducido en la adición y el grupo etilo. La estereoselectividad observada es atribuible a la reversibilidad de la reacción de adición conjugada de aniones estabilizados, lo que conduce al compuesto termodinámicamente más estable. La utilidad sintética de las anteriores reacciones de adición conjugada se ha puesto de manifiesto con la síntesis enantioselectiva de diversas piperidinas cis- y trans-3,4-disustituidas.

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15

Wallace, P. M. "Approaches to synthesis of beta-lactams." Thesis, University of Oxford, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.355808.

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16

Jones, Mark. "The enzyme catalysed formation of lactams." Thesis, University of Huddersfield, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293346.

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17

Nadin, Alan. "Medium ring lactams as peptidic constraints." Thesis, University of Cambridge, 1993. https://www.repository.cam.ac.uk/handle/1810/272640.

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18

Shah, Ajit Jesang. "The analysis of #beta#-lactams and their biosynthetic intermediates in fermentations of #beta#-lactam producing fungi." Thesis, University of Westminster, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358855.

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19

Derrer, Sam. "Medium ring lactams as peptide conformational constraints." Thesis, University of Cambridge, 1998. https://www.repository.cam.ac.uk/handle/1810/251637.

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20

Virden, Jane. "Chemical and enzymatic synthesis of #beta#-lactams." Thesis, University of Oxford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.253475.

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21

Dixon, Rachel Anne. "Asymmetric reduction of meso-imides and lactams." Thesis, University of Newcastle Upon Tyne, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.399101.

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22

Khaled, Arwa M. "Heterometallic complexes with lactams and related ligands." Thesis, Imperial College London, 1991. http://hdl.handle.net/10044/1/46864.

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23

Kenwright, Jayne Louise. "Synthesis of medium ring amines and lactams." Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608700.

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24

Philippe, Jules. "Pneumococcus morphogenesis and resistance to beta-lactams." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENV018/document.

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Streptococcus pneumoniae, le pneumocoque, est une bactérie pathogène qui entraîne le décès de plus d'un million et demi de personnes dans le monde chaque année. Les β-lactamines sont très utilisées pour traiter les infections à pneumocoques. Ces antibiotiques inhibent la synthèse du peptidoglycane, une molécule géante constituant un réseau de chaînes glycopeptidiques qui englobe la cellule, lui confère sa forme et lui permet de maintenir son intégrité face à la pression osmotique. Le mécanisme d'action des β-lactamines est bien connud'un point de vue biochimique. En revanche, la réponse physiologique empêchant la multiplication des bactéries traitées est mal connue. Au cours de ma thèse, j'ai étudié les mécanismes moléculaires de la morphogenèse du pneumocoque par des approches de biochimie et de microbiologie. Un modèle de morphogenèse est proposé intégrant mes résultats à la littérature et permettant de formuler des hypothèses sur la réponse physiologique de S. pneumoniae aux β-lactamines
Streptococcus pneumoniae, the pneumococcus, is a bacterial pathogen that causes more than 1.5 million deaths each year in the world. β-Lactams are widely used to treat patients with pneumococcal infections. These antibiotics inhibit the synthesis of the peptidoglycan, a giant molecule constituting a mesh of aminosugar strands encasing the cell. This main constituent of the cell wall allows cells to maintain their integrity under the turgor pressure, and endows bacteria with their shape. The action of β-lactams is well understood from a biochemical point of view. However, a complete understanding of the physiological response of treated bacteria remains elusive. In this thesis, I investigated the molecular mechanisms of the morphogenesis of S. pneumoniae using methods of biochemistry and microbiology. A morphogenesis model is built based on my results and the literature, which permits to emit hypotheses concerning the response of the pneumococcus to β-lactams

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25

Micheli, Bernard Jean Marie. "NMR studies of dimeric and polymeric lactams." Diss., The University of Arizona, 1990. http://hdl.handle.net/10150/185270.

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The aim of this work was to study the solution conformation of dimeric and polymeric 1actams. In a first part of this work, the synthesis of bicyc1odi1actams as precursors of the polymers was explored. A new preparation for the 2, 5-diazabicyc1o [2,2,2] octa-3, 6-dione was developed. The dimers and polymers were obtained from the N-protected cis- and trans- 3-amino-6-carboxy-2-piperidone for which an improved synthesis was found. Base treatment of the trans activated ester led to the polymer. Using the methods of solution phase peptide synthesis, the four possible dimers were prepared. After transformation to the paranitrophenyl esters, they polymerized to oligomeric species under the same treatment. The solution conformation of the monomeric, dimeric and polymeric species was determined by 1- and 2-dimensional NMR techniques. The 1actam rings have a chair-like conformation in solution. The cis- 1actam is a powerful β-turn- inducer when incorporated in synthetic peptides. The cis- lactam was found, however, to have a very similar conformation in DMSO solution, without hydrogen bonding to stabilize the turn. No evidence was found for the β-turn in the dimers and polymers using 2-dimensional NMR techniques. The dimers were found to exist in an extended conformation in DMSO. The fact that every other amide bond is in the cis configuration, as well as the steric crowding due to the rings may not allow the existence of the β-turn.

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26

Dixit, A. N. "A) Nitroenamines, nitroacetamides and nitrothioacetamides: synthesis, conformation and reactivity B) ring opening reaction of lactams and lactam ethers." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 1995. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/2829.

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27

Westwood, Nicholas James. "Synthetic and mechanistic studies on the inhibition of elastases." Thesis, University of Oxford, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306872.

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28

Shakya, Sagar Raj. "Studies on alpha,alpha-disubstituted bicyclic beta-lactams." Thesis, University of Ottawa (Canada), 1992. http://hdl.handle.net/10393/7571.

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General Organization. This thesis contains a brief introduction to the area of $\beta$-lactam antibiotics and four other Chapters dealing with the syntheses of various 6-methoxy $\beta$-lactams. Due to the tremendous level of activity in this area the introductory literature material is presented in an illustrative approach rather than a comprehensive approach. Literature surveys were carried out using Chemical Abstracts from 1982 to February 1992. Experimental details are given at the end of each Chapter. Compounds in the schemes which did not lead to desired conclusion were not completely characterized; $\sp1$H NMR and other spectral data whenever available are given in the Experimental section. IR was not recorded in most of these cases. Elemental analyses were not performed at all, since the data from such experiments do not always represent the purity of product. Chapter 1. This section describes the development of various $\beta$-lactam antibiotics, major representative structures, mode of action and overall objectives of the research undertaken. Chapter 2. 7-Methoxy-7-ethyl and 7-methoxy-7-hydroxyethylisocephem analogs were prepared from 4-cinnamyl-3-methoxyazetidinone which was prepared in a multigram scale. This precursor can be purified simply by trituration with ether. The transformation of this monocyclic starting material to the cyclization precursor involved introduction of an additional side-chain at C-3 via. generation of anion using lithium diisopropylamide and quenching of the anion with either ethyl iodide or acetaldehyde. In the case of the hydroxyethyl side-chain oxidation with pyridinium chlorochromate, reduction with L-Selectride and silylation with tert-butyldimethylsilyl triflate was required before carrying out further manipulations. The cinnamyl group was converted to a methylene bearing a leaving group and the p-methoxyphenyl moiety on nitrogen was cleaved and a suitable acetate side-chain was introduced. The anionic annulation with CS$\sb2$ gave the desired bicyclic compounds. An optically active isocephem having a thienamycin type side-chain at C-7 and and a racemic isocephem having a methoxy group at C-7 were prepared by similar method. Chapter 3. 7-Ethyl-7-methoxycarbacephem was prepared using a rhodium carbenoid reaction starting from 4-cinnamyl-3-methoxyazetidinone. A similar method was applied to prepare an advanced intermediate for 7-hydroxyethyl-7-methoxycarbacephem. Chapter 4. 6-Methoxy-PS 5 synthesis was attempted which was found to be unstable. The cyclization was carried out applying the rhodium carbenoid methodology. The cyclization precursor was obtained using nitroaldol condensation starting from an aldehyde which was prepared from 4-cinnamyl-3-methoxyazetidinone. Chapter 5. Syntheses of 6-methoxy-1-methyl-PS 5 analogs were attempted starting from 3-ethyl-3-methoxy-4-methylcinnamylazetidinone. The introduction of 1-methyl group involved the reduction of a suitable $\alpha,\beta$-unsaturated ester obtained via. palladium catalyzed carbonylation reaction.

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29

Kang, T. W. "Novel synthesis of #beta#-lactams via radical pathways." Thesis, University of Oxford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379970.

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30

Goswami, Rajesh. "Bicyclic lactams for the synthesis of functionalised heterocycles." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365826.

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31

Gardiner, James. "Conformationally restricted amino acid analogues based on lactams." Thesis, University of Canterbury. Chemistry, 1998. http://hdl.handle.net/10092/8773.

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This thesis describes the synthesis of enamino esters 3(S)-(E)-benzoylamino-3-benzyl- 5-ethoxycarbonylmethylidene-1-methylpyrrolidin-2-one 77, and 3(S)-(E)-benzoylamino-3-benzy 1-5-ethoxycarbonylmethylidene-1-2, 4-dimethoxybenzy lamino-pyrrolidin-2-one 79. These were designed as a new class of conformationally restricted amino acid analogue. Chapter one gives a general introduction to the importance of peptides in nature and the pivotal role peptides play in drug discovery and design. A number of examples are examined to provide an insight into key elements required in peptidomimetic design. Chapter two introduces the process of peptidomimetic design, in particular that of cisamide bond mimics. The synthesis of a new class of conformationally restricted peptidomimetic based on lactams is examined. Chapter 3 discusses the synthesis of succinic acid-derived, and aspartic acid-derived, β-keto esters and amides 23, 24, 28, via a Meldrum's acid procedure. This method provides the basis for the preparation of cyclic enamino esters. The preparation of the β-keto amide methyl-5-(N-ethoxycarbonylmethylcarbamoyl)-4-oxo-pentanoate 24 allowed chain extension in the C-direction in one easy step. Chapter 4 examines the importance of ene-lactams in nature and the synthesis of enamino esters 55, 56, 59, 61, and enamino amides 63 and 64,.via the reaction of a β-keto ester, or amide, with an amine. Compounds 59 and 61 represent examples of 3- substituted cis-amide bond mimics that allow chain extension in both the N and C directions and subsequent incorporation into a peptide sequence. Chapter 5 describes the synthesis of the target phenylalanine-derived 3,3-disubstituted enamino esters 77 and 79, using the methodology established in chapter 4. Reaction of the enolate derived from (2R, 4S)-2-phenyl-3-benzoyl-4-benzyl-1,3-oxazolidin-5-one 65, with tert-butylbromoacetate gave (2R, 4S)-2-phenyl-3-benzoyl-4-benzyl-4-(tertbutyloxycarbonylmethyl)-1,3-oxazolidin-5-one 67. An x-ray crystal structure of 67 revealed that the reaction had proceeded with an inversion of configuration at C4, with the oxazolidinone ring being essentially planar in the solid state. This also revealed that the stereochemistry at C3 could be determined by the stereochemistry of the amino acid from which it was derived. The tert-butyl ester was hydrolyzed and the resulting acid was converted to the β-keto ester 71 upon reaction with meldrum's acid and EtOH. The β-keto ester (2R, 4S)-2-pheny 1-3 -benzoy 1-4-benzy 1-4-(3 -ethoxycarbony 1-2-oxopropyl)-1 ,3-oxazolidin-5-one 71, was reacted with either methylamine, or 2,4- dimethoxybenzylamine (DMBNH₂), and heated at 150°C, under reduced pressure, to give the target 3,3-disubstituted enamino esters 77 and 79. The target enamino ester 77 and 79 allow chain extension in both the N and C-directions and are designed to be incorporated into a peptide sequence to mimic a cis-amide bond and allow investigation into the bio-active conformation of a specific peptide.

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32

Pink, Jennifer Helen. "Synthesis of fused lactams via N-acyliminium ions." Thesis, University of Sheffield, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242373.

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33

Ajavakom, Anawat. "Novel radical based routes to pyrrolidine trans lactams." Thesis, University of Southampton, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288468.

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34

Fontana, Francesco. "Stereoselective synthesis of β-lactams and carpanone derivatives." Paris 6, 2008. http://www.theses.fr/2008PA066441.

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SECTION A Nous décrivons la synthèse de nouveaux dérivés 4-spiro--lactamiques, au moyen de réactions de Staudinger entre des cétènes dérivant des -aminoacides cycliques énantiopurs (dérivés protégés de l’acide 1,3-thiazolidine-2-carboxylique et de la 4-hydroxy-L-proline) et des imines riches en électrons. Nous avons ensuite évalué la réactivité des composés obtenus conduisant à des produits -lactamiques mono- ou polycycliques totalement nouveaux et intéressants. SECTION B La carpanone est un lignane possédant cinq centres stéréogènes contigus qui a été isolée sous forme racémique de l'arbre carpano. A l’heure actuelle, il n’existe qu’une seule stratégie de synthèse de cette molécule limitée quant à la diversité moléculaire. Nous avons mis au point une nouvelle synthèse plus flexible que la seule méthode décrite jusque là et permettant d’obtenir facilement une librairie d’analogues. Nous avons obtenu alors la carpanone en six étapes à partir du sésamol, avec un rendement global de 55%.

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35

Fontana, F. "Stereoselective synthesis of beta-lactams and Carpanone derivatives." Doctoral thesis, Università degli Studi di Milano, 2008. http://hdl.handle.net/2434/61024.

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36

Kale, A. S. "Studies in synthesis and transformations of β-lactams." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2007. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/2613.

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37

Tiwari, D. K. "Diastereoselective synthesis of β - Lactams and their applications." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2011. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/3802.

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38

Naz, Summia. "A calorimetric study of β-sultams and β-lactams." Thesis, University of Huddersfield, 2009. http://eprints.hud.ac.uk/id/eprint/6975/.

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The hydrolytic degradation of a series of β-sultams and β-lactams was investigated using isothermal microcalorimetry (IMC), to determine kinetic and enthalpic data. The importance of these studies was to model the process of hydrolysis as this was a simplification of the mechanism by which β-lactams and β-sultams function as serine protease inhibitors. Calorimetric studies were conducted using a Thermal Activity Monitor (TAM 2277). Three categories of experiments were conducted: in the solid state, varying relative humidity (R/H) and in aqueous solution. Hydrolytic rate constants and enthalpies were determined for the solid state studies and these were related to substituent effects. However, for the experiments relating to the R/H studies no conclusive results were obtained. As expected, for solution state studies the hydrolytic rate constant in all cases changed with temperature (298K, 310K and 323K). Theoretical predictions were then made for a novel β-sultam based on these results with an excellent correlation observed between theoretical calculations and experimental results. Finally, calorimetric experiments were conducted on a series of β-lactams. This was for two reasons firstly; to determine if calorimetry can monitor low reaction rates and secondly; to compare rates of hydrolysis with the β-sultams. For a series of β-lactams, solution state hydrolytic rate constants and enthalpies were determined. An overall comparison of β-lactams and β-sultams appeared to indicate that in all cases β-lactams reacted slower than β-sultams.

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39

Baugh, Simon Peter. "Alkene metathesis in the synthesis of novel #beta#-lactams." Thesis, Imperial College London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.300539.

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40

Bahajaj, Abood Ahmed. "Asymmetric synthesis of spiro lactams via n-acyliminium ions." Thesis, University of York, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241062.

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41

Brown, Giles A. "The azomethine ylide approach to novel bicyclic #beta#-lactams." Thesis, University of Bristol, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302062.

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42

Jackson, Lynn. "Inhibition of elastase and trypsin by novel β-lactams." Thesis, University of Edinburgh, 2002. http://hdl.handle.net/1842/15094.

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Elastase is a serine protease that has been implicated in a number of inflammatory conditions including rheumatoid arthritis and cystic fibrosis. These conditions are thought to result from an increased amount of active elastase in the body, caused by insufficient inhibition by endogenous inhibitors. Elastase has the ability to degrade many tissue components and this excessive tissue damage causes the onset of a variety of conditions. This knowledge has led to an increased interest in the production of elastase inhibitors with the hope of developing an inhibitor, which can be of therapeutic use in vivo. As a result we have synthesised a series of novel β-lactams since β-lactam compounds are known to be mechanism-based inhibitors of serine proteases. Electrospray ionisation mass spectrometry (ESI-MS) identified a novel mode of inhibition, for β-lactams which possess a hydroxyl group present at the C3 position, resulting in the formation of an acyl-enzyme intermediate which was found to be extremely stable. Enzyme kinetic studies demonstrated that the β-lactams had k_ass values ranging from 1000 - 10,000 M^-1 s^-1. The novel β-lactams were also assayed for activity against trypsin. ESI-MS confirmed that they were also inhibitors or trypsin but enzyme kinetic studies revealed that they were more active towards elastase. Therefore the novel β-lactams were found to be stable, potent and specific inhibitors of elastase that may of therapeutic use in the treatment of many inflammatory conditions.

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43

Ghirardi, Elena. "Enantio- and Diastereoselective Cyclocondensation Reactions. Stereocontrolled Access to Azabicycles and Application to Natural Product Synthesis." Doctoral thesis, Universitat de Barcelona, 2016. http://hdl.handle.net/10803/398789.

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The first objective of this Thesis was the study of the preparation of octhydro-1H-cyclopenta[b]pyridines and octahydro-1H-indoles, through the synthesis of (R)-phenylglycinol derived tricyclic lactams. Following the previous reported methodology a carbon substituent would be present at the carbocyclic ring and we planned to find the conditions for controlling its absolute configuration. Unfortunately, the reaction of ketoester 4 and ketoacid 7, provided undesired enamines 8 and 9. On the other hand, the reaction of ketoacid derivatives 16 and 17 with (R)-phenylglycinol led to a mixture of epimeric amides 18. With the aim to extend the methodology, we planned to study the cyclocondensation reaction of (R)-phenylglycinol and (1S, 2R)-aminoindanol with C-3 and C-5 substituted cyclohexanepropionate derivatives. These reactions provided enantiopure tricyclic or pentacyclic lactams: in every run, a major lactam was isolated or identified, and a minor one was detected. The use of (1S, 2R)-aminoindanol resulted in better results. These tricyclic and pentacyclic lactams are precursors of C-8 (and C-6,8) substituted cis-decahydroquinolines. The conversion required the stereoselective reductive cleavage of C-O oxazolidine bond with simultaneous reduction of lactam carbonyl group, and debenzylation. A library of enantiopure cis-decahydroquinolines was obtained. To illustrate the usefulness of our method, we decided to undertake the synthesis of some alkaloids of Myrioneuron nutans family, which contain an 8-substituted cis-decahydroquinoline core. In particular, we prepared the enantiopure alcohol 82, which was described to be a common intermediate in the synthesis of various Mirioneuron nutans alkaloids. Our synthetic procedure greatly improved the previous results reported for the synthesis of this alcohol. The cyclocondensation reaction of (R)-phenylglycinol and (1S,2R)-aminoindanol with 3-alkyl-2-oxo-cyclohexane-1-acetate derivatives was finally considered. Reaction of (R)-phenylglycinol and 3-alkyl-2-oxocyclohexaneacetate derivatives 97-100 and 107 provided with high yield and stereoselectivity tricyclic lactams 110, 112a, 114, 116 and 118, which incorporate an alkyl or aryl substituent at C-10, while (1S,2R)-aminoindanol did not furnish so good outcomes. These reactions stereoselectively provided an additional minor hexahydroindole by-product. The absolute configuration of these compounds 111a, 113a, 115a and 117a was confirmed by X-ray crystallography. In the case of any or aryl substituent at C-10 of the tricyclic lactam, no by products were detected. We demonstrated that these unsaturated products derived from the opening of the oxazolidine ring of the minor lactams, which are epimers at C-10 of the major lactams, in the presence of acids. The stereoselective opening of the oxazolidine ring of the major lactams, in the presence of strong acids provided unsaturated compounds 111b, 113b, 115b and 117b, in which H-7 and H-7a resulted in cis relative disposition. In the case of lactam 118, with an aryl substituent at C-10, provided the unsaturated compound 125, in which H-7 and H-7a are in relative trans disposition. This different relative configuration can be accounted for by considering the structure rigidity of this system. Major tricyclic lactams were converted into C-7 exo substituted cis-octahydroindoles and cis-octahydroindolones, by selection of the appropriate reductive conditions. Hexahydroindolones 111b, 113b, 115b and 117b were converted stereoselectively into the corresponding enantiopure C-7 endo substituted cis-octahydroindolones, by catalytic hydrogenation of the carbon-carbon double bond, followed by elimination of the chiral inductor through reaction with sodium radical. Moreover, these hexahydroindolones and 125 were transformed into the corresponding trans-octahydroindolones 146c-149c and 126b by simultaneous reduction and debenzylation in sodium ammonia. The presence of the amide function allowed the stereoselective insertion of a new substituent by a-alkylation and a-amidoalkylation. Finally, in order to demonstrate the utility of this methodology, (+)-a-Lycorane was synthesized in only four steps, starting from easily available ketone 171, in 35% of overall yield, which resulted an improvement with respect to previously reported synthesis.
El primer objetivo de esta Tesis Doctoral ha sido el estudio de la preparación de octahidro-1H-ciclopentapiridinas y octahidro-1H-indoles, a través de la síntesis de lactamas tricíclicas derivadas del (R)-fenilglicinol. Desafortunadamente, la reacción del ceto-éster 4 y del ceto-ácido 7, proporcionó solamente las eniminas 8 y 9. Por otro lado, la reacción de los derivados de ceto-ácidos 16 y 17 con (R)-fenilglicinol rindió únicamente una mezcla de productos 18, amidas conjugadas epímeras en la posición C-7a. Se ha sido estudiado la reacción de ciclocondensación de derivados de 2-oxociclohexano propionato convenientemente sustituidos en C-3 o en C-3 y C-5 con (R)-fenilglicinol y (1S,2R)-aminoindanol. Esta reacción conduce estereoselectivamente a lactamas tricíclicas o pentacíclicas quirales: se aisló mayoritariamente una lactama y se detectó la presencia de otra minoritaria. Al utilizar (1S,2R)-aminoindanol se obtuvieron mejores resultados. Estas lactamas son precursoras de cis-decahidroquinolinas, con sustituyentes en la posición 8 o en la posición 6 y 8. Las etapas clave de esta transformación son la reducción con alano y la eliminación del inductor quiral. Con esta metodología se ha preparado la decahidroquinolina 82, precursor de numerosos alcaloides de la familia Mirioneuron nutans. Además, presentamos el estudio de las reacciones de ciclocondensación con (R)-fenilglicinol a partir de ciclohexanonas que poseen una cadena de acetato en la posición C-1 y diversos sustituyentes alquilo o arilo en la posición C-3. Esta reacción conduce estereoselectivamente a una sola lactama tricíclica de las ocho posibles. A partir de las cetonas con un sustituyente alquilo en la posición C-3 aislamos una cantidad variable de enamida. Las lactamas mayoritarias, fueron convertidas en cis-octahidroindoles y cis-octahidroindolonas, que presentan un sustituyente en la posición 7 o en las posiciones 7 y 7a del anillo carbocíclico. Además, estudiamos la reactividad de las lactamas tricíclicas en medio ácido: la reacción con TiCl4 en THF, proporciona lactamas insaturadas con elevada estereoselectividad y buen rendimiento. La presencia de la función enamida, nos permitió preparar selectivamente nuevas cis y trans octahidroindolonas. Esta metodología nos permitió sintetizar el (a)-Licorano, un metabolito de la familia de las Amaryllidaceae.

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Karstens, Willem Frederik Johan. "Palladium-catalyzed cyclization reactions of allene- and acetylene-substituted lactams." [S.l. : Amsterdam : s.n.] ; Universiteit van Amsterdam [Host], 2000. http://dare.uva.nl/document/83628.

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45

Houson, I. N. "Ring expansions in the synthesis of di- and tri-lactams." Thesis, University of Oxford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390511.

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46

Rahman, Adrian. "The synthesis of new tricyclic beta lactams based upon quinoline." Thesis, University of Liverpool, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366356.

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47

Thomas, Russell John. "The synthesis of novel #beta#-lactams with potential antifungal activity." Thesis, University of Exeter, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277147.

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48

Skytte, Dorthe. "Antimalarial norneolignans, synthesis and SAR & synthesis of beta-lactams /." Cph. : Danish University of Pharmaceutical Sciences, Department of Medicinal Chemistry, 2005. http://www.dfuni.dk/index.php/Dorthe_Mondrup_Skytte/2238/0/.

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49

Cirillo, Martina <1994&gt. "β-lactams from their structural features to their biological applications." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2022. http://amsdottorato.unibo.it/10378/1/%CE%B2-lactams%20from%20their%20structural%20features%20to%20their%20biological%20applications.pdf.

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β-lactam compounds represent an important class of four-membered cyclic amides (azetidin-2-ones) thanks to their valuable and varied biological activities. The presence of a β-lactam ring in a series of bioactive molecules targeting different proteins, allows us to consider the azetidin-2-one a privileged structure. The constrained four-membered cyclic amide could easily undergo ring-opening reactions by nucleophilic residues in the active sites of enzymes and this is the mechanism suggested for antibacterial activity; moreover, the rigid core structure could favour and actually enhance directional noncovalent bonding for an effective ligand−receptor recognition. Nowadays monocyclic β-lactams are known as anticancer, antidiabetic, anti-tubercular, anti-inflammatory agents and as ligands of integrin receptors. In order to consider different facets of 4-azetidin-2-ones, this theis will be divided into two sections: the first one will be dedicated to the design, synthesis and characterization of biological active β-lactams (new β-lactam based integrin ligands and their different applications and novel N-thio-alkyl substituted azetidinones for the treatment of Tuberculosis); the second one instead, will be based on two projects which consider two different proprieties of β-lactams: stereochemistry, evaluated by biocatalytic methods and reactivity at C-4 position. In the first case we want to obtain enantiomerically pure 4-acetoxy-2-azetidinone, useful for synthesis of stereo-chemically defined bioactive β-lactams, while in the second case we want to study in which conditions the nucleophilic substitutions occur. A final section will be instead dedicated to the research project conducted in Philochem AG, Zurich, under the supervision of Prof. Dario Neri and Dr. Samuele Cazzamalli, based on the study of new cleavable disulfide linkers for small molecule drug conjugates targeting Fibroblast activation protein (FAP).

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Shinkre, B. A. "Stereoselective synthesis of α-hydroxy acid derivatives and β lactams." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2004. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/2901.

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