Download or read book Synthesis of Spirocyclic Scaffolds by Aminoallylation RCM Sequence and Approach Toward the Total Synthesis of the Macrolide Dictyostatin written by Evgeny V. Prusov and published by . This book was released on 2008 with total page 253 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis of Benzomorphan Scaffolds by Intramolecular Buchwald Hartwig Arylation and Approach Towards the Total Synthesis of the Macrolide Queenslandon written by Anton S. Khartulyari and published by . This book was released on 2007 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis of Benzomorphan Scaffolds by Intramolecular Buchwald Hartwig Arylation and Approach Towards the Total Synthesis of the Macrolide Queenslandon written by Anton S. Khartulyari and published by . This book was released on 2007 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Studies Directed Toward the Total Synthesis of Aphidicolin written by Stacey Shepard and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Study of Heteroatomic Spirocyclic Scaffolds written by David George Hilmey and published by . This book was released on 2006 with total page 351 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Work presented in this thesis will demonstrate the synthetic progress made toward, and study of, various natural and unnatural products that can be utilized in a supramolecular capacity through ionic or biomacromolecular coordination. We have developed trispirocyclic tetrahydrofuranyl systems anchored onto inositol scaffolds and covalently linked them to various systems. Drug conjugates with a tamoxifen unit spaced by an acetylene linker to the trispirotetrahydrofuranyl Li+ ionophores were made with potential to increase drug bioavailability. Also, long alkyl and acyl chains were synthetically linked to these ionophores and could be elaborated into lipid mimics. Finally, trispiro ethers were coupled to transition metal cationic binders containing bi- and terpyridine subunits resulting in heterocationic lithium and transition metal chelation in predictable and distinct regions of the same molecular structure. The second area of spirocyclic research presented pertains to the synthesis and elaboration of 6-azaspiro[4.5]decane-1,7-dione into advanced intermediates of the natural products halichlorine and pinnaic acid. The spirocyclic core of these compounds imparts rigidity to their three-dimensional structures and thus provides for specific and potent supramolecular interactions in a biological setting. For example, these natural products demonstrate potential as anticancer agents through their inhibition of specific enzymes found in the inflammatory pathway. Utilization of a stereocontrolled, acid-promoted Beckmann rearrangement was key to the successful synthesis of 6-azaspiro[4.5]decane-1,7-dione. This ketone was then functionalized in a variety of ways including nucleophilic addition followed by reduction or acid induced rearrangement. Finally, stereoisomeric groups of straight-chained spirocyclic substituted ligands were synthesized with consecutively installed tetrahydrofuranyl rings of varying chain length. With varying stereochemistry at each carbon atom of a carbon backbone, many isomers are possible. We have successfully completed the full set of bis- and tris-(THF) structures as well as a small sampling of twelve hexa-(THF) compounds, which provide an excellent cross section of all possible isomers. A number of these polyethers were then analyzed through X-ray crystallography and computational methods to reveal their relative stereochemistry as well as some very unique conformational arrangements. Through this study, we have demonstrated the interdependence of acyclic polyspiro-substituted stereochemistry on conformational adoption as well as deformation from expected gauche interactions.

Download or read book The Development of a Four Component Reaction and Its Application to the Synthesis of Diverse Heterocyclic Scaffolds and the Total Synthesis of Alkaloid Natural Products written by James Dennis Sunderhaus and published by . This book was released on 2009 with total page 868 pages. Available in PDF, EPUB and Kindle. Book excerpt: A four component reaction involving the coupling of functionalized aldehydes, amines, acid chlorides, and [pi]- and organometallic nucleophiles has been developed to prepare multifunctional substrates that may be employed in subsequent ring-forming reactions to generate diverse arrays of functionalized heterocyclic scaffolds. Allyl metals, Grignard reagents, silyl ketene acetals, silyl enol ethers, and silyloxy furans have been utilized as the nucleophile in the four component reaction (4CR). The 4CR has been sequenced with intramolecular Heck reactions, Diels-Alder and (3+2) cycloadditions, ring closing metathesis (RCM), and Dieckmann condensations to provide a number of diverse heterocyclic structures. The practical utility of this approach to diversity-oriented synthesis (DOS) was further exemplified by its application to the first total synthesis of the isopavine alkaloid roelactamine, which was completed in only four steps from commercially available materials. The application of this methodology towards the synthesis of the Aspidosperma alkaloids rosicine and pseudotabersonine is also presented. To this end, an imine pentadienylation/double RCM strategy has been adopted to rapidly access the pentacyclic core of the aspidospermine alkaloids. This sequence involved the use of a pentadienyl aluminum reagent, which was found to react with aryl imines to give branched products in good yields.

Download or read book An Approach Toward the Total Synthesis of Cylindrospermopsin written by Jane F. Djung and published by . This book was released on 2001 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Towards the Total Synthesis of a Sesquiterpene Gamma lactone Scaffolding written by Ariana Maria Remmel and published by . This book was released on 2014 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt: