Download or read book Synthesis of Alkoxy Heterocyclic and Fused Rings Derivatives of S Nicotine from Natural Nicotine Progress Towards the Total Synthesis of S Macrostomine written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ONDACHI, PAULINE WANJIKU. Synthesis of Alkoxy, Heterocyclic and Fused-Rings Derivatives of (S)-Nicotine from Natural Nicotine, Progress towards the total synthesis of (S)-Macrostomine. (Under the direction of Dr. Daniel Lee Comins). (S)-Nicotine and its derivatives have drawn a lot of interest due to their potential pharmacological role in the treatment of Parkinsonâ€TMs disease, Alzheimerâ€TMs disease, and other central nervous system related disorders. Current synthetics efforts are directed towards the development of analogs that are more selective to specific subtypes of nicotinic acetylcholine receptors. Towards this goal, alkoxy, heterocyclic and fused-rings derivatives of (S)-nicotine were synthesized from natural nicotine as will be described herein. Methodologies were developed for the synthesis and regioselective substitution of enantiomerically pure alkoxy nicotine derivatives. Introduction of heteroaromatic rings at the C-4, C-5, and C-6 positions of the pyridine ring of nicotine and nicotine derivatives was achieved through the use of metal-catalyzed cross-coupling reactions. In addition, a variety of novel small molecules, cyclized ethers and fused-rings derivatives, were synthesized. Bicyclic dioxino, dihydrofuro and dihydropyranol nicotine derivatives, as well as tricylic benzofused-rings derivatives were synthesized as detailed in the third chapter of this document. Finally, a study directed towards the total synthesis of a plant alkaloid (S)-macrostomine was carried out. Efforts were centered on an attempt to utilize the Diels-Alder reaction to achieve a key intermediate in the synthesis.

Download or read book Synthesis of Alkoxy Heterocyclic and Fused rings Derivatives of s nicotine from Natural Nicotine Progress Towards the Total Synthesis of s macrostomine written by Pauline Wanjiku Ondachi and published by . This book was released on 2008 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: cyclic nicotine derivatives, alkoxynicotines, nicotine chemistry, ring-fused nicotine derivatives, (S)-Macrostomine, heterocycles.

Download or read book Progress Toward the Total Synthesis of the Epoxyquinoid Family of Natural Products written by and published by . This book was released on 2007 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: Enyne metathesis is a powerful C-C bond forming reaction that combines an alkene and an alkyne and forms a conjugated 1,3-diene. The scope of enyne metathesis was expanded by combining various alkynes with vinyl ethers. Typically vinyl ethers are poor metathesis substrates, but a method was developed for the synthesis of dienol ethers utilizing ruthenium carbenes. The products of these reactions were subjected to [4+2] cycloaddition conditions to give substituted cyclohexene rings. The epoxyquinoid family is a highly targeted series of natural products. A general method for the synthesis of the core structure of these natural products has been explored. An enyne cross metathesis/ring closing metathesis step was designed as the key reaction to this synthesis. A Darzen's condensation between a chiral [alpha]-alkoxy aldehyde and a chloroacyl oxazolidinone was successfully employed to join two fragments of the molecule as well as to install an epoxide. A highly diastereoselective cuprate addition set the stereochemistry of the first stereogenic center. The early intermediates were prepared via easily scalable organic syntheses procedures including utilizing a carbohydrate as the source of chirality. Ring closing enyne metathesis to form the epoxyquinoid core was evaluated in two epimeric series.

Download or read book Applied Cross Coupling Reactions written by Yasushi Nishihara and published by Springer Science & Business Media. This book was released on 2012-12-14 with total page 247 pages. Available in PDF, EPUB and Kindle. Book excerpt: “Applied Cross-Coupling Reactions” provides students and teachers of advanced organic chemistry with an overview of the history, mechanisms and applications of cross-coupling reactions. Since the discovery of the transition-metal-catalyzed cross-coupling reactions in 1972, numerous synthetic uses and industrial applications have been developed. The mechanistic studies of the cross-coupling reactions have disclosed that three fundamental reactions: oxidative addition, transmetalation, and reductive elimination, are involved in a catalytic cycle. Cross-coupling reactions have allowed us to produce a variety of compounds for industrial purposes, such as natural products, pharmaceuticals, liquid crystals and conjugate polymers for use in electronic devices. Indeed, the Nobel Prize for Chemistry in 2010 was awarded for work on cross-coupling reactions. In this book, the recent trends in cross-coupling reactions are also introduced from the point of view of synthesis design and catalytic activities of transition-metal catalysts.

Download or read book Development of Methodology to Synthesize S nicotine Derivatives written by Laura Stuart King and published by . This book was released on 2002 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: nicotine-N-oxide, nicotine, n-acylpyridinium salt, dihydronictines.

Download or read book Application of Inverse Electron Demand Diels Alder Reactions in Total Synthesis of Nothapodytine B mappicine Phomazazarin and Ent roseophilin written by Jiyong Hong and published by . This book was released on 2001 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concise total syntheses of naturally occurring nothapodytine B (mappicine ketone) and ( - )-mappicine are detailed. The approach was based on the implementation of a room-temperature, inverse electron demand Diels-Alder reaction of an N-sulfonyl-1-aza-1,3-butadiene for assemblage of a pyridone D-ring precursor central to the structure. A Friedlander condensation was utilized for constructing the AB-ring system of nothapodytine B and ( - )-mappicine. An acid-catalyzed reaction sequence was used to accomplish a deprotection with subsequent ring-closure for introduction of the C-ring in a single step. A concise total synthesis of phomazarin is detailed enlisting a heterocyclic azadiene inverse electron demand Diels-Alder reaction (1,2,4-triazine [arrow right] pyridine) for preparation of the fully substituted and appropriately functionalized pyridine C-ring. Thus, [4+2] cycloaddition of triethyl 1,2,4-triazine-3,5,6-tricarboxylate with 1,1,2-trimethoxyethylene followed by conversion of the cycloadduct to the cyclic anhydride provided the phomazarin C-ring with the three carboxylates suitably differentiated. Linkage of the A- and C-rings through selective nucleophilic addition of an aryl lithium reagent to the least hindered carbonyl of the cyclic anhydride followed by Friedel-Crafts closure of the B-ring provided the fully functionalized phomazarin skeleton. The successful structural correlation of synthetic phomazarin with natural material and its derivatives confirmed the latest structural assignment for the natural product. An asymmetric total synthesis of ent-( - )-roseophilin, the unnatural enantiomer of a novel antitumor antibiotic, was accomplished based on an approach enlisting a room temperature heterocyclic azadiene inverse electron demand Diels-Alder reaction of dimethyl 1,2,4,5-tetrazine-3,6-dicarboxylate with an optically active enol ether bearing the C23 chiral center, followed by a reductive ring contraction reaction for formation of an appropriately functionalized pyrrole ring in a key 1,2,4,5-tetrazine [arrow right] 1,2-diazine [arrow right] pyrrole reaction sequence. A Grubbs' ring closing metathesis reaction was utilized to close the unusual 13-membered macrocycle prior to a subsequent 5- exo - trig acyl radical-alkene cyclization that was used to introduce the fused cyclopentanone and complete the preparation of the tricylic ansa-bridged azafulvene core. Condensation of the tricyclic core with the heterocyclic side chain followed by final deprotection provided (22S,23S)-roseophilin. Comparison of synthetic (22S,23S)-roseophilin ([[alpha]] [superscript]25 [subscript]D, CD) with natural roseophilin established that they were enantiomers and enabled the assignment of the absolute stereochemistry of the natural product as 22R,23R. Surprisingly, ent-( - )-roseophilin was found to be 2-10-fold more potent than natural (+)-roseophilin in cytotoxic activity.

Download or read book Application of Iminium Activation Technologies to Natural Product Synthesis Total Syntheses of the Spiculisporic Acids Progress Towards the Total Synthesis of Cylindrocyclophane F and Formal Synthesis of Cylindrocyclophane A written by Nicole Cathleen Goodwin and published by . This book was released on 2007 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first enantioselective, catalytic vinylogous Mukaiyama-Michael reaction of siloxyfurans with simple alpha,beta-unsaturated aldehydes has been reported using chiral imidazolidinones. This methodology provides access to enantioenriched gamma-butenolides, a privileged motif in organic synthesis. The utility of this organocatalytic Mukaiyama-Michael reaction was highlighted by the total syntheses of (-)-spiculisporic acid and (-)-5- epi-spiculisporic acid.

Download or read book PROGRESS TOWARD THE TOTAL SYNTHESIS OF 14 ISOAZACAMPTOTHECIN AND SYNTHESIS OF SUBSTITUTED QUINOLINES written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: BORI, IBRAHIM DANLAMI. Progress Toward the Total Synthesis of 14-Isoazacamptothecin, and Synthesis of Substituted Quinolines. (Under the direction of Professor Daniel Lee Comins.) Studies were conducted with the purpose of completing the first total synthesis of 14-isoazacamptothecin. During the courses of this endeavor, new insights into pyridine chemistry were uncovered. It was demonstrated for the first time that C-4 substitution of 2,5-dibromopyridine via C-4 lithiation is indeed possible. New reactions in heterocyclic chemistry, namely (a) “Halogen Dance-Lithium Migration-Halogen Dance†or “Lithium Migration-Halogen Dance†and (b) Double Halogen Dance†were discovered to have taken place as explanations for the observation of unexpected products. Synthetic methods toward the synthesis of new quinoline analogs using readily available and inexpensive starting materials were developed. Although the initial inspirational target of the project was the AB ring fragment of CPT analogs, new techniques and methods were developed that would be useful in far reaching applications such as in the synthesis of clinically useful compounds and natural products containing a quinoline ring in the parent structure.

Download or read book Asymmetric Organocatalysis in Complex Target Synthesis written by Robert R. Knowles and published by . This book was released on 2009 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Alkaloids written by S. William Pelletier and published by . This book was released on 1983 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Pyridines From Lab to Production written by Eric F.V. Scriven and published by Academic Press. This book was released on 2013-01-08 with total page 583 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pyridines: From Lab to Production provides a synthetic armory of tools to aid the practicing chemist by reviewing the most reliable historical methods alongside new methods/ Written by scientists who have actually used these in synthesis. By emphasizing tricks and tips to optimize reactions for the best yields and purity, which are often missing from the primary literature, this book provides another dimension for the synthetic chemist. A combined academic and industrial approach evaluates the best methods for different scales of reaction and discusses practical tips (e.g. when to stop a reaction early to maximize purity or when to re-use side products). Chapters also assess whether to make or source starting materials, how to connect them and what are the best synthetic routes. The book is designed to be a stand-alone reference, but also provides cross references to leading reviews and the Comprehensive Heterocyclic Chemistry reference works for those who want to learn more. Reviews tried and tested practical methods to help the reader select the best method for their research Includes tips, tricks and hints to enable the reader to get the best yield or cleanest product out of their reaction for synthesising or transforming a pyridine derivative Written by both academic researchers and industry leaders this provides a unique view of how to get the most out of a reaction no matter what scale you are running this on

Download or read book Arene Chemistry written by Jacques Mortier and published by John Wiley & Sons. This book was released on 2015-11-30 with total page 992 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organized to enable students and synthetic chemists to understand and expand on aromatic reactions covered in foundation courses, the book offers a thorough and accessible mechanistic explanation of aromatic reactions involving arene compounds. • Surveys methods used for preparing arene compounds and their transformations • Connects reactivity and methodology with mechanism • Helps readers apply aromatic reactions in a practical context by designing syntheses • Provides essential information about techniques used to determine reaction mechanisms

Download or read book Bioactive Heterocyclic Compound Classes written by Clemens Lamberth and published by John Wiley & Sons. This book was released on 2012-08-16 with total page 367 pages. Available in PDF, EPUB and Kindle. Book excerpt: The chemistry of heterocycles is an important branch of organic chemistry. This is due to the fact that a large number of natural products, e. g. hormones, antibiotics, vitamins, etc. are composed of heterocyclic structures. Often, these compounds show beneficial properties and are therefore applied as pharmaceuticals to treat diseases or as insecticides, herbicides or fungicides in crop protection. This volume presents important pharmaceuticals. Each of the 20 chapters covers in a concise manner one class of heterocycles, clearly structuredas follows: * Structural formulas of most important examples (market products) * Short background of history or discovery * Typical syntheses of important examples * Mode of action * Characteristic biological activity * Structure-activity relationship * Additional chemistry information (e.g. further transformations, alternative syntheses, metabolic pathways, etc.) * References. A valuable one-stop reference source for researchers in academia and industry as well as for graduate students with career aspirations in the pharmaceutical chemistry.

Download or read book Modified Nucleosides written by Piet Herdewijn and published by John Wiley & Sons. This book was released on 2008-09-08 with total page 684 pages. Available in PDF, EPUB and Kindle. Book excerpt: Edited by one of the main driving forces behind the field's momentous rise in recent years, this one-stop reference is the first comprehensive resource to integrate recent advances. The first part addresses biochemical aspects and applications, the second and third parts are devoted to compounds with therapeutic potential, with the third part focusing on newly introduced anticancer nucleoside drugs. Essential reading for every scientist working in this area.

Download or read book Palladium in Organic Synthesis written by Jiro Tsuji and published by Springer Science & Business Media. This book was released on 2005-07-06 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: with contributions by numerous experts

Download or read book Modern Aryne Chemistry written by Akkattu T. Biju and published by John Wiley & Sons. This book was released on 2021-08-23 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt: A groundbreaking book to offer a a comprehensive account of important reactions involving arynes Modern Aryne Chemistry is the first book on the market to offer a conceptual framework to the reactions related to arynes. It also provides a systematic introduction to the cycloaddition reactions, insertion reactions and transition-metal-catalyzed transformations of arynes. The author, a noted expert on the topic, highlights a novel strategy for carbon-carbon and carbon-heteroatom bond construction using arynes. The book reveiws the recent use of aryne chemistry for the development of new multicomponent reactions. New advances in this area has shown rapid emergence of a new class of reactions classified under rearrangement reactions. The author also includes information on aryne methods that have been employed for the synthesis of several natural products. The simplicity and sophistication of the synthetic strategy using arynes can serve as a springboard for organic chemists to explore new possibilities and imagine applications of the concept of arynes. This important book: Presents a one-of-kind comprehensive guide to arynes reactions Offers a proven approach to the synthesis of natural product and polymers Reviews the most recent developments in the carbon-carbon and carbon-heteroatom bond-forming reactions involving arynes Written for organic, pharmaceutical, medicinal, natural products, and catalytic Chemists, Modern Aryne Chemistry offers a comprehensive review of the fundamentals of reactions related to arynes and the most recent developments in the field.

Download or read book Isoquinoline Alkaloids Research 1972 1977 written by Maurice Shamma and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt: