Download or read book Application of the Prins Cyclization to a Synthesis of the Tetrahydropyran Rings of Lasonolide A written by Ruth Figueroa and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: This thesis describes studies toward the synthesis of the tetrahydropyran-containing marine macrolide lasonolide A.A summary of studies done by Lee and coworkers, that led to a revision of the structure as well as its first total synthesis is presented. This is followed by a literature review of the partial and completed syntheses of lasonolide A reported by other groups. The studies presented are based on the use of a Prins cyclization as the key reaction. The cyclization uses vinylogous carbonates as the source to generate the oxocarbenium ion. Therefore, we first introduce the background that led to the development of this reaction. The Prins cyclizations were promoted using trifluoroacetic acid and the products were immediately hydrolyzed to afford in most of the cases the tetrahydropyran rings as the major product. The cyclization of alkyne derived vinylogous carbonates resulted in instability of the product to the reaction conditions. Also, formation of 5-membered ring was a competing pathway. Vinlogous carbonates derived from Z-alkenes gave the all cis-2,3,4,6-tetrahydropyran in 59-70% yield. The E-alkene derived enol ethers gave the C3 epimeric tetrahydrofuran. Inversion of the secondary alcohol in the tetrahydropyran ring was partially accomplished using a Mitsunobu reaction. This methodology led to the racemic and asymmetric syntheis of the B ring of lasonolide A. The racemic synthesis was accomplished in 8 steps from 3-buten-1-ol. An asymmetric synthesis was also accomplished in 12 steps from (R)-malic acid. The quaternary stereogenic center of the A ring of lasonolide A was constructed via C-H insertion reaction using Doyle's catalyst (Rh2(4R-MEOX)4).
Download or read book The Silyl Enol Ether Prins Cyclization written by Gidget C. Tay and published by . This book was released on 2015 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: A modular synthesis of the reportedly potent molluscicide, cyanolide A, was developed to provide facile access to a series of cyanolide A analogues. The synthesis of strategic derivatives was initiated in order to determine the structural features of cyanolide A required for molluscicidal activity. Cyanolide A was synthesized in twelve steps with an overall 2% yield. After extensive SAR studies, it was found that cyanolide A was not responsible for the reported molluscicidal activity observed in the original studies. A diastereoselective synthesis of cis-2,6-disubstituted tetrahydropyran-4-ones was developed. The key step of this methodology, a silyl enol ether Prins cyclization, was promoted by a condensation reaction between a hydroxy silyl enol ether and an aldehyde to afford substituted tetrahydropyran-4-ones. The cyclization was tolerant of many functional groups, and the modular synthesis of the hydroxy silyl enol ether allowed for the formation of more than thirty new tetrahydropyran-4-ones with up to 97% yield and >95:5 dr. The cyclization step forms new carbon-carbon and carbon-oxygen bonds, as well as a quaternary center with good diastereoselectivity. The method provides a versatile route for the synthesis of substituted tetrahydropyrans. The scope and diastereoselectivity of an intramolecular aza-Diels-Alder reaction starting from a variety of 2-cyano-1-aza-1,3-butadienes was explored. The key reactions involved in synthesizing the Diels-Alder precursors are an imine condensation and a Strecker reaction and subsequent oxidation. The method provides a route for the synthesis of substituted quinolizidine and indolizidine heterocycles containing a cyanoenamine functional group. A visual aid teaching tool, the DanceChemistry video series, has been developed to teach fundamental chemistry concepts through dance. These educational videos portray chemical interactions at the molecular level using dancers to represent chemical species. Students reported that the DanceChemistry videos helped them visualize chemistry ideas in a new and memorable way. Surveying the general laboratory course at the University of California, Irvine (n = 1266), 75% of the students said they wanted to use these videos to learn additional chemistry topics in the future. Data from pre- and post-surveys show an increase in students' average scores after watching a five minute DanceChemistry video. These instructional videos are disseminated broadly through a dedicated YouTube channel, DanceChemistry.
Download or read book Prins Cyclization in Tetrahydropyran Synthesis and a Unified Approach for the Synthesis of Antifungal Polyene Macrolides written by Yueqing Hu and published by . This book was released on 1998 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2005 with total page 858 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Directory of Graduate Research written by American Chemical Society. Committee on Professional Training and published by . This book was released on 2005 with total page 1932 pages. Available in PDF, EPUB and Kindle. Book excerpt: Faculties, publications and doctoral theses in departments or divisions of chemistry, chemical engineering, biochemistry and pharmaceutical and/or medicinal chemistry at universities in the United States and Canada.
Download or read book Current Organic Chemistry written by and published by . This book was released on 2007 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides in depth reviews on current progress in the fields of asymmetric synthesis, organometallic chemistry, bioorganic chemistry, heterocyclic chemistry, natural product chemistry, and analytical methods in organic chemistry. Each issue is edited by an appointed Executive Guest Editor
Download or read book Metal and Nonmetal Assisted Synthesis of Six Membered Heterocycles written by Navjeet Kaur and published by Elsevier. This book was released on 2020-04-25 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal and Nonmetal Assisted Synthesis of Six-Membered Heterocycles provides a useful guide to key approaches being explored in this area. The volume highlights synthetic approaches and catalytic options that facilitate the construction of multiple substituted molecules under mild conditions from easily available starting substrates. Drawing on the experience of its expert author, the book is a useful guide on the key approaches being explored in this area. Following a user-friendly structure based on specific six-membered heterocycle ring groups, this volume highlights synthetic approaches and catalytic options that facilitate the construction of multiple substituted molecules under mild conditions from easily available starting substrates. Highlights new methodologies for the synthesis of different six-membered heterocycles Provides an up-to-date overview of this fast-moving field with an easy-to-use structure Includes novel approaches used in the study and application of catalysts in synthetic organic reactions
Download or read book Hetero Diels Alder Methodology in Organic Synthesis written by and published by Elsevier. This book was released on 2012-12-02 with total page 379 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic Chemistry: A Series of Monographs, Volume 47: Hetero Diels-Alder Methodology in Organic Synthesis focuses on the use of hetero Diels-Alder reactions as pivotal steps in natural product total syntheses. The publication first offers information on N-sulfinyl compounds and sulfur diimides and imino dienophiles. Discussions focus on sulfur dioxide and related compounds, selenium dioxide, sulfur diimide cycloadditions, regiochemical, stereochemical, and mechanistic aspects, iminium salts and neutral imines, oximino compounds, and intramolecular cycloadditions. The text then takes a look at nitroso and thionitroso dienophiles and carbonyl dienophiles. The manuscript elaborates on thiocarbonyl and selenocarbonyl dienophiles and miscellaneous dienophiles. Topics include nitriles, azo compounds, selenoaldehydes, thioketones, thioesters, dithioesters, and related compounds, and thiophosgene and related compounds. The text also ponders on oxabutadienes, thiabutadienes, and azabutadienes. The publication is a valuable reference for chemists and readers interested in the Hetero Diels-Alder methodology.
Download or read book Contemporary Aspects of Boron Chemistry and Biological Applications written by Hijazi Abu Ali and published by Elsevier. This book was released on 2005-09-07 with total page 631 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contemporary Aspects of Boron: Chemistry and Biological Applications highlights the biological activity and applications of boron containing compounds. The authors’ specific approach surveys general features of the subject, while exploring new and novel strategies for preparing certain chemical and natural boron products that are of significant substance in medicinal chemistry. For example, cancer treatment is one of the most important issues related to such products. In addition to contributing to the development of new drugs by addressing biological applications in medicinal and industrial fields, the book provides a comprehensive review of the most relevant components that comprise the pharmaceutical, medicinal and environmental applications of boron containing compounds. * Timely and comprehensive * Provides new insights to active researchers in the field * Presents concepts and methods in simple scientific terms
Download or read book Organic Synthesis written by Douglass F. Taber and published by Oxford University Press. This book was released on 2017 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt: A collection of Douglass Taber's columns originally published between 2013 - 2015 at www.organicchemistry.org
Download or read book Medicinal Plants of South Asia written by Muhammad Asif Hanif and published by Elsevier. This book was released on 2019-09-14 with total page 768 pages. Available in PDF, EPUB and Kindle. Book excerpt: Medicinal Plants of South Asia: Novel Sources for Drug Discovery provides a comprehensive review of medicinal plants of this region, highlighting chemical components of high potential and applying the latest technology to reveal the underlying chemistry and active components of traditionally used medicinal plants. Drawing on the vast experience of its expert editors and authors, the book provides a contemporary guide source on these novel chemical structures, thus making it a useful resource for medicinal chemists, phytochemists, pharmaceutical scientists and everyone involved in the use, sales, discovery and development of drugs from natural sources. Provides comprehensive reviews of 50 medicinal plants and their key properties Examines the background and botany of each source before going on to discuss underlying phytochemistry and chemical compositions Links phytochemical properties with pharmacological activities Supports data with extensive laboratory studies of traditional medicines
Download or read book Practical Medicinal Chemistry with Macrocycles written by Eric Marsault and published by John Wiley & Sons. This book was released on 2017-09-12 with total page 617 pages. Available in PDF, EPUB and Kindle. Book excerpt: Including case studies of macrocyclic marketed drugs and macrocycles in drug development, this book helps medicinal chemists deal with the synthetic and conceptual challenges of macrocycles in drug discovery efforts. Provides needed background to build a program in macrocycle drug discovery –design criteria, macrocycle profiles, applications, and limitations Features chapters contributed from leading international figures involved in macrocyclic drug discovery efforts Covers design criteria, typical profile of current macrocycles, applications, and limitations
Download or read book Synthesis of Heterocycles in Contemporary Medicinal Chemistry written by Zdenko Časar and published by Springer. This book was released on 2016-07-01 with total page 281 pages. Available in PDF, EPUB and Kindle. Book excerpt: The series Topics in Heterocyclic Chemistry presents critical reviews on present and future trends in the research of heterocyclic compounds. Overall the scope is to cover topics dealing with all areas within heterocyclic chemistry, both experimental and theoretical, of interest to the general heterocyclic chemistry community. The series consists of topic related volumes edited by renowned editors with contributions of experts in the field. All chapters from Topics in Heterocyclic Chemistry are published Online First with an individual DOI. In references, Topics in Heterocyclic Chemistry is abbreviated as Top Heterocycl Chem and cited as a journal.
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 Medicinal Natural Products A Disease Focused Approach written by and published by Academic Press. This book was released on 2020-09-21 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt: Medicinal Natural Products: A Disease-Focused Approach, Volume 55 in the Annual Reports in Medicinal Chemistry series, highlights the applications of natural products as medicines or prospective medicinal leads for the treatment of various human ailments. Each chapter covers a particular disease area or medical condition, with chapters in this new release covering Medicinal Natural Products – An Introduction, Anticancer Natural Products, Antimicrobial Natural Products, Antimalarial and Antiparasitic Natural Products, Anti-inflammatory Natural Products, Neuroprotective Natural Products, Hepatoprotective Natural Products, Nephroprotective Natural Products, Cancer Chemopreventive Natural Products, Antipsoriatic Natural Products, Medicinal Natural Products in Osteoporosis, Antidiabetic Natural Products, Anti-obesity Natural Products, and much more. Presents a disease-focused perspective Includes the latest on the medicinal chemistry of natural products Covers natural products in drug delivery
Download or read book Comprehensive Heterocyclic Chemistry III written by and published by Elsevier Science. This book was released on 2008-03-27 with total page 12500 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive Heterocyclic Chemistry III (CHEC-III) is a new 15-volume reference work which provides the first point of entry to the literature for all scientists interested in heterocyclic ring systems. Since publishing in 1984, Comprehensive Heterocyclic Chemistry (CHEC) has become the standard work on the subject, indispensable to all serious readers in the interdisciplinary areas where heterocycles are employed. CHEC-III builds on and complements the material in CHEC and CHEC-II and is designed to be used both alone and in conjunction with these two works. Written by leading scientists who have evaluated and summarized the most important data published over the last decade, Comprehensive Heterocyclic Chemistry III will be an invaluable addition to the reference library of those working with heterocyclic ring systems. Reviews advances in the properties, structure, synthesis, reactivity and applications of the most important heterocyclic ring systems Contains over 250 specialist reviews, logically organized by size and heteroatom content of the heterocyclic ring Saves researchers valuable time and effort through carefully structured critical reviews of the literature by experts
Download or read book Modern Carbonyl Chemistry written by Junzo Otera and published by John Wiley & Sons. This book was released on 2008-11-21 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt: The carbonyl group is undoubtedly one of the most important functional groups in organic chemistry, both in its role as reactive center for synthesis or derivatisation and as crucial feature for special structural or physiological properties. Vast and profound progress has been made in all aspects modern carbonyl chemistry. These achievements are, however, rather dispersed in the literature and it is often not easy for the researcher obtain a comprehensive overview of a relevant topic. Modern Carbonyl Chemistry overcomes this inconvenience by collating the information for appropriate themes. In this work internationally renowned experts and leaders in the field have surveyed recent aspects and modern features in carbonyl chemistry, such as cascade-reactions, one-pot-syntheses, recognition, or site differentiation.
