Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Download Towards The Total Synthesis Of Amphidinolides C And F full books in PDF, epub, and Kindle. Read online Towards The Total Synthesis Of Amphidinolides C And F ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Author : Ludovic Decultot
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (16 download)
Download or read book Towards the Total Synthesis of Amphidinolides C and F. written by Ludovic Decultot and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Daniel A. Mills
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (126 download)
Download or read book Towards the Total Synthesis of Amphidinolide F. written by Daniel A. Mills and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Subham Mahapatra
Publisher :
ISBN 13 :
Total Pages : 639 pages
Book Rating : 4.:/5 (828 download)
Download or read book Part I: Total Synthesis of Marine Macrolide Amphidinolide F and Synthetic Studies Toward Amphidinolide C written by Subham Mahapatra and published by . This book was released on 2013 with total page 639 pages. Available in PDF, EPUB and Kindle. Book excerpt: More than 30 members of the diverse amphidinolide family of biologically active macrolides have been isolated over last three decades. From this family, amphidinolides C and F stand among the most complex and densely functionalized affiliates. Recently, we have accomplished the first total synthesis of amphidinolide F. The all-carbon framework of amphidinolide C has been synthesized. During endeavor toward the total syntheses of amphidinolides F / C, we have uncovered a "hidden symmetry element" present in the northern and southern domains of amphidinolides F / C. The southern C1-C and northern C1-C25 tetrahydrofuran segments were derived from a common intermediate. A scalable silver-catalyzed isomerization / cyclization on propargyl-benzoate / diol furnished the common intermediate in multigram quantity. The common intermediate provided access to over half of carbon backbone of the macrocycle as well as majority of stereochemistry present in amphidinolides F / C. Two strategically different techniques have been developed for the C9-C11 diene preparation. A metal-catalyst free Weinreb amide-vinyl lithium coupling / methylenation sequence furnished the diene motif. Alternately, diastereoselective addition of a dienyl iodide derived 2-lithio-1,3-diene species to an [alpha]-oxy aldehyde installed the C9-C11 diene and secured the C8 stereochemistry in single operation. The dienyl iodide was prepared via a regioselective hydrostannylation on an enyne. A challenging alkylation between an [alpha]-branched sulfone and an [alpha]-silyloxy iodide generated the all-carbon frameworks of amphidinolides F / C. An efficient oxidative desulfurization incorporated the carbonyl moiety at C15. The protecting group on C18 alcohol was found to have significant effect on the sulfone-iodide alkylation / oxidative desulfurization sequence. Installation of chelating ethoxyethyl ether on C18 alcohol helped the successful incorporation of C15 ketone and solved the deprotection problem in advanced stage of synthesis. A detailed analytical and computational study on proline sulfonamide-catalyzed aldol reactions has been performed. The pKa value of a proline sulfonamide catalyst was determined experimentally via NMR titration technique. Computational study revealed the origin of enhanced stereoselectivity by proline sulfonamide catalysts over parent proline. The non-classical hydrogen bonding interactions were found to be responsible for improved diastereoselectivity.
Author : Robert H. Bates
Publisher :
ISBN 13 :
Total Pages : 394 pages
Book Rating : 4.:/5 (763 download)
Download or read book Studies Toward the Total Synthesis of Amphidinolide C written by Robert H. Bates and published by . This book was released on 2009 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt: Amphidinolide C is one of the most biologically potent members of the amphidinolide family of natural products. Detailed in this thesis are studies toward the total synthesis of this complex macrolide. Three distinct syntheses of the C(1)-C(9) fragment are described. The first generation synthesis involves a diastereoselective chelate-controlled [3+2]-annulation reaction to form the C(3)-C(6) trans tetrahydrofuran. The second generation approach takes advantage of the C(4) methyl substituent to induce diastereoselectivity in an intramolecular hetero-Michael cyclization to form the same tetrahydrofuran. The third generation incorporates a non-chelate-controlled [3+2]-annulation reaction to afford the cis tetrahydrofuran product, followed by a base-promoted epimerization to the desired trans tetrahydrofuran. This route was accomplished in fewer steps than the first generation synthesis. Also described are stereoselective syntheses of the C(18)-C(34) C(10)-C(26) fragments of amphidinolide C, and the C(10)-C(29) fragment of amphidinolide F, a closely related natural product. Finally, a clear plan for the completion of the total synthesis of amphidinolide C is presented.
Author : Guang Yang
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (875 download)
Download or read book Towards the Total Synthesis of Amphidinolide C written by Guang Yang and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Nicholas A. Morra
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (16 download)
Download or read book Progress Towards the Total Synthesis of Amphidinolide C written by Nicholas A. Morra and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A second generation catalyst for the Mukaiyama oxidative cyclization for the formation of trans-THF rings is described. Co(nmp)2, displays increased stability to the reaction conditions, resulting in lower catalyst loadings, lower reaction temperatures, and significantly higher purity and yields of the products. Three procedures have been developed with this new water-soluble catalyst that greatly simplifies the post-reaction purification, making this procedure the premier method of forming trans-THF rings. This new catalyst has been applied towards the total synthesis of the potently bioactive macrocycle, Amphidinolide C. Herein we report the successful synthesis of several fragments of the natural product, and our attempts at coupling them to complete the synthesis. The C(1)-C(9) was achieved via two routes, both utilizing the highly effective oxidation catalyst Co(nmp)2 to form the methyl substituted trans-THF ring. Synthetic highlights include a regioselective Shi epoxidation, and the design and introduction of a novel Lewis acid (BF2OBn×OEt2) to facilitate a stereoselective reductive epoxide opening. The C(18)-C(34) fragment was also achieved via two routes, culminating in both the shortest (11 steps) and highest yielding (26% overall yield) approaches to this segment. Synthetic highlights of this fragment include a selective methylation of a diyne, and a highly selective alkynylation of a THF aldehyde, achieving excellent dr (>20:1) without the addition of an external chiral compound. Advanced intermediates comprising the entirety of the carbon backbone of the molecule have been synthesized, which in theory could complete the total synthesis in as few as two bond forming steps.
Author : Matthew A. Foster
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (643 download)
Download or read book Studies Towards the Total Synthesis of Amphidinolides O and P written by Matthew A. Foster and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Michael J. McCoy
Publisher :
ISBN 13 :
Total Pages : 198 pages
Book Rating : 4.3/5 ( download)
Download or read book Studies Toward the Total Syntheses of Amphidinolides C and F written by Michael J. McCoy and published by . This book was released on 2007 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Andrew Frederick Nolting
Publisher :
ISBN 13 :
Total Pages : 194 pages
Book Rating : 4.X/5 (3 download)
Download or read book Progress Towards the Total Synthesis of Amphidinolide E written by Andrew Frederick Nolting and published by . This book was released on 2006 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Brian J. Myers
Publisher :
ISBN 13 :
Total Pages : 428 pages
Book Rating : 4.3/5 ( download)
Download or read book Studies Toward the Synthesis of the Amphidinolides written by Brian J. Myers and published by . This book was released on 2000 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Flavien Labre
Publisher :
ISBN 13 :
Total Pages : 233 pages
Book Rating : 4.:/5 (816 download)
Download or read book Towards the Total Synthesis of Amphidinolide T Family written by Flavien Labre and published by . This book was released on 2012 with total page 233 pages. Available in PDF, EPUB and Kindle. Book excerpt: Amphidinolides T are challenging natural targets for the total synthesis community because of their unique structural architecture. This thesis describes the investigations of the establishment of a novel and convenient route to synthesise four members of the natural product family, amphidinolides T1 and T3-5, from a common late-stage intermediate. The key transformations towards the synthetic pathway are ring formation reactions. The trans-tetrahydrofuran ring is forged efficiently via diastereoselective [2,3]-sigmatropic rearrangement of an oxonium ylide from diazo-generated metal carbenoids. Coupling of a side chain is achieved using a sequence of esterification and RCM reactions. Alternatively, a one-pot RCM followed by hydrogenation is described to shorten the synthetic route.
Download or read book Towards the Synthesis of Amphidinolides C, F and U written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Lamont R. Terrell
Publisher :
ISBN 13 :
Total Pages : 530 pages
Book Rating : 4.3/5 (129 download)
Download or read book The Total Synthesis of the Assigned Structure of Amphidinolide A written by Lamont R. Terrell and published by . This book was released on 2002 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Joseph Samuel Ward
Publisher :
ISBN 13 :
Total Pages : 396 pages
Book Rating : 4.3/5 (129 download)
Download or read book The Total Synthesis of the Proposed Structure of Amphidinolide A written by Joseph Samuel Ward and published by . This book was released on 2002 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Natalie E. Campbell
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (13 download)
Download or read book Towards a Total Synthesis of ( - )-amphidinolide K written by Natalie E. Campbell and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Yan Yu
Publisher :
ISBN 13 :
Total Pages : 52 pages
Book Rating : 4.:/5 (513 download)
Download or read book Studies Toward Total Synthesis of Amphidinolide A written by Yan Yu and published by . This book was released on 2001 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Daniel C. Akwaboah
Publisher :
ISBN 13 :
Total Pages : 308 pages
Book Rating : 4.:/5 (16 download)
Download or read book Synthetic Study of Amphidinolides C, C2, C3, and F written by Daniel C. Akwaboah and published by . This book was released on 2017 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: Amphidinolides C, C2, C3, and F are cytotoxic secondary metabolites that occur naturally from symbiotic marine dinoflagellates Amphidinium sp. from the Okinawan flatworm. They share an identical 25-membered macrolide core that possesses 11 stereogenic centers and two trans-2,5-disubstituted tetrahydrofuran ring systems. The only structural difference resides in the appended C25–C34 triene side chain. Although the biological mode of action for these anticancer natural products has not been fully elucidated, the C29 functionality is known to significantly impact activity. Our contribution to the amphidinolide project was designed to assemble a common macrolide framework which could be elaborated with minimal synthetic manipulations to access all four target molecules. We recognized a hidden structural homology that allowed for the scalable syntheses of the southern C1–C9 and the northern C11–C25 fragments from a common starting material, D-gluconic acid delta-lactone. Z-selective Ando’s modification of the Horner–Wadsworth–Emmons olefination was employed to efficiently prepare the C3–C5 acrylate. This was crucial to install the C4 methyl group via ensuing diastereoselective substrate-controlled hydrogenation. The two endocyclic trans-tetrahydrofuran scaffolds were constructed with two strategically different intramolecular transformations in high diastereoselective ratios: (1) a kinetically-driven fluoride-mediated oxy-Michael cyclization to form the southern C3–C6 ring, and (2) a thermodynamically-controlled Hartung’s modification of Mukaiyama’s aerobic cobalt-catalyzed cyclization to access the northern C20–C24 ring. We utilized a chelation-controlled Mukaiyama aldol reaction to form the C13–C14 bond and to concomitantly incorporate the C13 hydroxyl substituent. Subsequently, C11 terminal functionalization was accomplished with Seyferth–Gilbert homologation to complete the synthesis of the C10–C25 advanced fragment of the target amphidinolides.
