Download or read book Towards the Enantioselective Synthesis of Lycoricidine Alkaloids written by Ruowei Mo and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies Toward the Enantioselective Total Synthesis of the Martinella Alkaloids written by Vivek Badarinarayana and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation consists of two parts. The first part describes the enantioselective total synthesis of martinellic acid. The Martinella alkaloids have attracted considerable attention in the synthetic community over the past few years. This interest is due in large part to their unique structure and useful biological activity (bradykinin receptor antagonist). In model systems we have successfully used the [3+2] azomethine ylide-alkene cycloaddition to construct the heterocyclic core of these alkaloids. The enantioselective approach described herein also involves the azomethine ylide-alkene cycloaddition as a key step in the total synthesis. The pyrrolo[3,2-c]quinoline core of this alkaloid was constructed in an enantioselective fashion by the elaboration of an N-aryl pyrrolidinone, which was obtained via Pd-catalyzed aryl amination reaction using a non-racemic lactam. Pirkle's chiral solvating agent was successfully used to demonstrate the stereochemical integrity of not only the N-aryl lactam (obtained by Pd-catalyzed cross-coupling) but also the cycloaddition precursor and the cycloaddition product (tetracyclic pyrroloquinoline core). The tetracyclic compound obtained via the azomethine ylide-alkene cycloaddition was elaborated to ( - )-martinellic acid in 11 steps and 6% overall yield. The second part of this dissertation describes application of several novel organometallic complexes for carrying out various organic transformations. A fluorinated tris(pyrazolyl)borato silver(I) complex catalyzes the addition of ethyl diazoacetate to benzene rings, providing norcaradienes, which undergo electrocyclization to provide the corresponding cycloheptatriene (the Bu & huml;chner reaction). These reactions are surprisingly selective for addition to the aromatic moiety rather than C-H insertion. A copper complex containing a fluorinated triazapentadienyl ligand has been used to catalyze some carbene and nitrene addition and insertion chemistry. Nitrene addition occurs rapidly and with both aryl and alkyl substituted olefins providing the corresponding aziridine. The carbene transfer reactions that were attempted include C-H insertion, O-H insertion and N-H insertion, of which the latter two were very efficient.
Download or read book Studies toward the synthesis of natural products written by Terrance Lee Clayton and published by . This book was released on 1993 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Recent Applications of Selected Name Reactions in the Total Synthesis of Alkaloids written by Majid M. Heravi and published by Elsevier. This book was released on 2021-06-12 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent Applications of Selected Name Reactions in the Total Synthesis of Alkaloids includes comprehensive coverage of name reactions in the synthesis of alkaloids. This book highlights the synthesis of various alkaloids using special name reactions including the Diels-Alder, Friedel-Crafts, Heck, Mannich, Pauson-Khand, Pictet-Spengler, Sonogashira and Suzuki reactions. In this book, some selected name reactions in the total synthesis of alkaloids are covered, as they can be used as the key step/steps in the synthesis of different alkaloids exhibiting various biological activities. All chapters include an introduction, history and mechanism of the name reaction, and present the origin of the natural product and its known biological activities. The pathway to total synthesis is visually illustrated, and the focus is on the step in which a name reaction is applied. Chemists working in the area of synthetic organic chemistry will find this reference useful, as well as those working to develop novel methodologies for the synthesis of natural products in both academia and industry. This book is also beneficial to biologists, pharmacists and botanists. Includes an introduction of alkaloids, their origins and biological properties Features the applications of special name reactions as the key step in the total synthesis of featured alkaloids Covers the pathway for the synthesis of alkaloids from commercially available or easily accessible starting materials by using at least one name reaction to achieve the desired target products
Download or read book Alkaloid Synthesis written by Hans-Joachim Knölker and published by Springer Science & Business Media. This book was released on 2012-01-10 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lycopodium Alkaloids: Isolation and Asymmetric Synthesis, by Mariko Kitajima and Hiromitsu Takayama.- Synthesis of Morphine Alkaloids and Derivatives, by Uwe Rinner and Tomas Hudlicky.- Indole Prenylation in Alkaloid Synthesis, by Thomas Lindel, Nils Marsch and Santosh Kumar Adla.- Marine Pyrroloiminoquinone Alkaloids, by Yasuyuki Kita and Hiromichi Fujioka.- Synthetic Studies on Amaryllidaceae and Other Terrestrially Derived Alkaloids, by Martin G. Banwell, Nadia Yuqian Gao, Brett D. Schwartz and Lorenzo V. White.- Synthesis of Pyrrole and Carbazole Alkaloids, by Ingmar Bauer and Hans-Joachim Knölker.-
Download or read book Studies Towards an Enantioselective Synthesis of Methyllycaconitine Analogues written by Christopher Ritchie and published by . This book was released on 2005 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Enantioselective Approach to Securinega Alkaloids written by David González Gálvez and published by . This book was released on 2009 with total page 221 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies Toward the Enantioselective Synthesis of the Gelsemium Alkaloids written by Christopher Matthew Harrington and published by . This book was released on 2019 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: Developments in catalysis using late transition metals, such as gold and platinum, have provided an abundance of transformations that are useful to the organic chemist. The unique alkynophilic properties of these metal catalysts is a consequence of relativistic effects, which allows these metals to function in reactions as more than just a Lewis acid. Herein, we sought to discover new modes of reactive nucleophilic partners fot ß-unsaturated platinum carbenes, in particular, nucleophiles which also contained a heteroatom. In addition, we were interested in converting our previous racemic synthesis of gelsenicine into an enantioselective synthesis by utilizing a chirality transfer approach. Two generations of substrates were created in order to see if such a strategy would prove successful.
Download or read book Indole Alkaloids written by Maliha Uroos and published by Elsevier. This book was released on 2022-01-30 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Indole Alkaloids: Spirooxindole details the multistep synthesis of natural products using schematic diagrams, providing a quick-and-easy way to review and understand new and novel synthetic strategies to construct structural frameworks of natural products. As a volume in the Visual Guides to Natural Product Synthesis series, this book presents the schematic total syntheses of natural products containing a “spirooxindole” core structure. It covers spirooxindole molecules through visual diagrams, highlighting key steps involved in total, formal and semi-syntheses. Sections cover Brevianamide A and B, Citrinadin A and B, Coerulescine and Horsfiline, Elacomine and Isoelacomine, Gelsemine, Paraherquamide A and B, Rynchophylline, Isorynchophylline, and more. Visual layouts provide quick-and- easy access to developed synthetic routes towards the targeted spirooxindoles. Outlines synthetic strategies for natural products bearing a spirooxindole core structure Includes schematic diagrams of multistep synthetic routes, highlighting key steps along the way Describes all routes for the formal synthesis, semi-synthesis and total synthesis of spirooxindole alkaloids
Download or read book Chemoenzymatic Enantioselective Synthesis of Alkaloids written by Michael Dickman and published by . This book was released on 1996 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Part I The Enantioselective Synthesis of Adaline and Related Alkaloids Part II The Synthesis of Specifically Labeled Dihydrouracils written by Louis Allan Renbaum and published by . This book was released on 1981 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemoenzymatic Enantioselective Synthesis of Alkaloids microform written by Michael Dickman and published by National Library of Canada = Bibliothèque nationale du Canada. This book was released on 1996 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Total Synthesis of Dimeric Pyrrole imidazole Alkaloids written by Daniel Patrick O'Malley and published by ProQuest. This book was released on 2008 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes the synthesis of the dimeric pyrrole-imidazole alkaloids sceptrin, ageliferin, nagelamide E, oxysceptrin, nakamuric acid, nakamuric acid methyl ester, axineallamine A, and axinellamine B. The total synthesis of racemic sceptrin was accomplished by the fragmentation of an oxaquadricyclane to establish the cyclobutane core, followed by attachment of the pyrrole sidechains and elaboration of the 2-aminoimidazole units. Microwave irradiation of sceptrin yielded the natural products ageliferin and nagelamide E. An enantioselective synthesis of sceptrin was effected by means of an enzymatic desymmetrization and careful modification of the oxaquadricyclane fragmentation conditions. The absolute configuration of ageliferin was determined by synthesis from enantiopure sceptrin, highlighting the possibility that sceptrin may be the biosynthetic precursor of ageliferin. A computational study of the formation of ageliferin indicates that this reaction likely proceeds via a radical fragmentation mechanism. Biosynthetic considerations led to the synthesis of oxysceptrin, nakamuric acid, and nakamuric acid methyl ester from sceptrin. Attempts to obtain the cyclopentyl core of the axinellamines, massadines, and palau'amines culminated in the development of a ring contraction of ageliferin. However, the stereochemistry of the spiro ring junction formed in this reaction was opposite that found in the natural products. Finally, the total synthesis of axinellamines A and B by closure of a linear intermediate and studies on oxidation of intermediates formed in this route are discussed.
Download or read book Pyrrolizidine Alkaloids microform Enantioselective Synthesis of Necine Bases and a Study of the Alkaloids of Senecio Triangularis Hook written by Heinrich Ernst Rüeger and published by National Library of Canada. This book was released on 1983 with total page 670 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Enantioselective Synthesis of Indole Alkaloids written by Timothy Edward Wilson and published by . This book was released on 1993 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies Directed Towards the Enantioselective Total Synthesis of Trans Dihydrolycorcidine written by William L. Brown and published by . This book was released on 1989 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Part I The Enantioselective Synthesis of Pyrrolizidine Alkaloids Using acylamino Radical Cyclizations Part II The Enantioselective Synthesis of the Indolizidine Alkaloid swainsonine Using an acylamino Radical Cyclization written by Jeffrey Mark Dener and published by . This book was released on 1988 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:
