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Showing 1 to 20 of 28 for “"Pyrone"”.
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Towards the total synthesis of Phacelocarpus-2-pyrone A: Novel 2-pyrone chemistry
… synthesis of the natural product phacelocarpus-2-pyrone A and the development of novel synthetic methodology for the synthesis of functionalised 2-pyrones. Initial studies focused on the synthesis of the natural product and the applications of Pd-catalysed cross-coupling reactions using the …
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Synthese von Cyclopenta[c]pyran-3(5H)-on und Cyclopenta[c]pyran-3(7H)-on als Vorstufen von Cyclopenta[c]pyranen
Die bisher unbekannten a-Pyrone Cyclopenta[c]pyran-3(5H)-on und Cyclopenta[c]pyran-3(7H)-on wurden auf zwei unabhängigen Synthesewegen hergestellt. Die Reaktivität der neuen a-Pyrone wurde untersucht. Das Hauptaugenmerk lag dabei auf der Synthese von Cyclopenta[c]pyranen.
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The arylation of 2-pyrones and related heterocycles
2-Pyrones, and related heterocycles such as 2-pyridones, 2-coumarins and 2- quinolones, are useful model substrates to test a novel methodology due to their varied chemical properties. In addition, these moieties possess broad spectrum biological activity. Chapter 1 provides a review of C–H …
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Cyclization modes in type III polyketide synthases and the synthetic compounds used as probes for mechanistic studies.
… with distinct ring structures. The mechanisms of pyrone and resorcinol ring formation in type III PKSs remain unknown, despite many years of research on this family of enzymes. Compounds, thought to be intermediates in these enzyme reactions, have been synthesized and used to probe the enzyme …
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2-Pyranones as Suicide Inhibitors for Alpha-Chymotrypsin: I. A Structure-Activity Study of the 6-Halo-2-Pyranones. Ii. 5-Halomethyl-2-Pyranones as Inhibitors of Chymotrypsin
… series, substitution in the 3- position of the pyrone by either ethyl or n-butyl produced poor binding relative to 3-benzyl-6-chloro-2-pyranone, and no inactivation. Increasing the aromatic area of the binding group by replacing the benzyl group with a naphthylmethyl had a dramatically different …
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Mechanistic and Synthetic Studies of Oxidopyrylium Cycloaddition Reactions
… we describe our examination of 3-hydroxy-4-pyrone-derived oxidopyrylium cycloadditions in both mechanistic considerations as well as the unique synthetic advancements of their corresponding cycloadducts. Chapter 1 is a literature review where we specifically outline the use of oxidopyrylium …
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The development of new synthetic methods for chromone and ergochrome construction
… an intramolecular Diels-Alder reaction to form a pyrone ring or - (b) an intermolecular Diels-Alder reaction and subsequent Friedel-Crafts cyclisation to give a pyrone ring.<br/><br/>For this, a selenium dlene protection, alkylatlon and deprotection methodology was developed. Depending upon the …
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Studies Toward a General Synthesis of Poly-Substituted Alpha-Hydroxytropolones
… <p>Chapter 2: A brief review on β-hydroxy-γ-pyrone based oxidopyrylium cycloadditions will be presented as well as important oxidopyrylium cycloaddition/ring opening procedures to yield natural tropolone products. Research from the Murelli laboratory will be highlighted. This chapter will …
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Direct arylation of 2-pyrones, coumarins, 2-pyridinones and 2-quinolones
… Stille, etc.) coupling reactions. The 2-pyrone, coumarin, 2-pyridinone and 2-quinolone moieties are prevalent in numerous compounds which exhibit biological activity. In addition, due to the varied chemistry that these compounds display, they represent an excellent substrate scope to …
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Developing green processes for the conversion of biobased materials into pyrones
… chapter we developed a methodology to generate -pyrones. This moiety was formed by a [3+3] reaction between a 1,3 dicarbonyl and dihaloacryloyl chloride. Bicyclic -pyrones could be transformed into 5-hydroxychomones by aromatization in good yields.</p> <p>In the third chapter, we found new …
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Total Synthesis of Lasionectrin and Synthetic Studies Towards Pestaloxazine A
… synthesis and structural confirmation of naphthopyrone lasionectrin (13), which was extracted from the fungus Lasionectra sp. and exhibited antimalarial activity (IC50 = 11 μM). Lasionectrin (13) is a naphthalene derivative which contains a fused pyrone-tetrahydrofuran ring system. Several …
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Palladium and manganese catalysis in C-H activation
… in terms of waste, cost and atom economy. 2-Pyrone and 2-coumarin analogues represent privileged biological scaffolds and possess broad spectrum biological activity. Importantly, there have been limited reports of catalytic methods involving the C-H activation of 2-pyrones and 2-coumarins. …
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Exploring hetero-atom derivatization in maltols and flavonols : the effect on reactivity of flavonol dioxygenation.
… natural products containing a 3-hydroxy pyrone core. They have been found to have several desirable properties such as anti-fungal, anti-bacterial, anti-mutagenic and anti-carcinogenic properties and they act as UV filters in plants. Flavonols display dual excitation-emission manifolds …
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The significance of volatile antifungal metabolites produced by trichomerma harzianum biotype Th4, in green-mould disease of commercial mushroom crops /
… indicating that it belongs to a class of pyrone antibiotics characterised from other T. harzianum biotypes. UV absorption spectra indicated this compound was not 6-pentyl-2H-pyran-one (6PAP), the volatile antifungal metabolite widely described in Th1. Furthermore, this compound was not …
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Investigação da atividade espasmolítica do extrato etanólico bruto das partes aéreas de Hyptis macrostachys Benth. (Lamiaceae) e do seu composto isolado HM308.
… extract from H. macrostachys was obtained a pyrone (HM308). Thus, in this work was investigated a possible spasmolytic effect of ethanolic extract of aerial parts from Hyptis macrostachys Benth. (HM-EtOHPA) and its isolated compound, HM308, on smooth muscle models. We observed that on rat …
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SYNTHESIS OF NATURAL PRODUCT NEPETANUDONE THROUGH THERMALLY FORBIDDEN [4Π+4Π] CYCLOADDITION IN THE PRESENCE OF LIGHT
… through the cycloadditon of two Nepetapyrones (5,9-dehydronepetalactone). This precursor pyrone was synthesized in the laboratory through six step reaction pathways as shown in Scheme 4. Once this compound was developed, it was photolyzed at different conditions and the formation of the …
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Design, Chemical Synthesis and Biological Evaluation of Potential New Antiviral Agents
… group present in the structure of some amino-pyrone compounds using the standard method, resulted in the expected N-acylation, but with a C-acyl byproduct. This result has suggested to look further into the study of N,C-acylation selectivity for the ambidentate amino-pyrone moiety, whose …
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Design, synthesis, and evaluation of bioactive molecules; Chiral polyvinylpyrrolidones supported Cu/Au nanoclusters catalyzed cyclization of 5-substituted nona-1,8-dien-5-ols
… the treatment of seizure and epilepsy. Tricyclic pyrone derivatives were reported as anti-Alzheimer lead compounds in previous research done by the Hua group. TP70 and CP2 were synthesized to explore their pharmacokinetics properties. Chapter 4 described chiral-substituted poly-N-vinylpyrrolidones …
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Operation Hot Sandwich: Incorporating pyrones in [4 + 2] cycloaddition reactions to prepare thermorubin
… including a new method for incorporating pyrone moieties into aromatic systems. Based off the Hauser annulation, these conditions were successfully used to insert 15 different pyrones esters and amides into an aromatic system as a dieneophile or a 2-electron component. Modification of the …
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Synthesis and Biological Evaluation of Novel Glycomimetics
… are described. The second chapter explored using pyrone cycloaddition to synthesise pseudodisaccharides as potential Golgi α-mannosidase II inhibitors. The synthesis is performed over seven steps. Further optimisation is needed to increase the overall yield. Also, an enzyme assay has to be …
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