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Burton JW, Anderson EA, O'Sullivan PT, Collins I, Davies JE, Bond AD, Feeder N, Holmes AB. The Claisen rearrangement approach to fused bicyclic medium-ring oxacycles. Org Biomol Chem 2008; 6:693-702. [DOI: 10.1039/b715354f] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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52
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Abstract
Since its discovery in 1993, the marine natural product palau'amine has intrigued natural product chemists. Its exotic molecular architecture and purported bioactivity made it an ideal target for synthesis. However, as the years went by and related marine alkaloids were isolated, a skeptical eye was cast on the structure of palau'amine; recently these suspicions were confirmed and the structure of palau'amine revised. This Minireview gives a careful overview of the structural revision and its ramifications to both its biogenesis and total synthesis.
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Affiliation(s)
- Matthias Köck
- Alfred-Wegener-Institut für Polar- und Meeresforschung in der Helmholtz-Gemeinschaft, Am Handelshafen 12, 27570 Bremerhaven, Germany.
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55
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Abstract
Selectivity rules in organic chemistry have been inferred largely from nonaqueous environments. In contrast, enzymes operate in water, and the chemical effect of the medium change remains only partially understood. Structural characterization of the "ladder" polyether marine natural products raised a puzzle that persisted for 20 years: Although the stereochemistry of adjacent tetrahydropyran (THP) cycles would seem to arise from a biosynthetic cascade of epoxide-opening reactions, experience in organic solvents argued consistently that such a pathway would be kinetically disfavored. We report that neutral water acts as an optimal promoter for the requisite ring-opening selectivity, once a single templating THP is appended to a chain of epoxides. This strategy offers a high-yielding route to the naturally occurring ladder core and highlights the likely importance of aqueous-medium effects in underpinning certain noteworthy enzymatic selectivities.
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Affiliation(s)
- Ivan Vilotijevic
- Massachusetts Institute of Technology, Department of Chemistry, Cambridge, Massachusetts, 02139, USA
| | - Timothy F. Jamison
- Massachusetts Institute of Technology, Department of Chemistry, Cambridge, Massachusetts, 02139, USA
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56
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Abstract
A second-generation synthesis of the BCDE fragment of brevetoxin A is described. Novel reactions were developed that extend the utility of the asymmetric glycolate alkylation reaction and improve scale-up to provide gram quantities of the B and E subunits. Significant improvements to the convergent assembly of the tetracycle were also realized. In addition, formation of the A ring lactone was accomplished to complete the ABCDE pentacycle.
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Affiliation(s)
- Michael T Crimmins
- Venable and Kenan Laboratories of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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57
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Sasaki M. Development and Application of a Convergent Strategy for the Total Synthesis of Polycyclic Ether Natural Products. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2007. [DOI: 10.1246/bcsj.80.856] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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59
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Negishi EI. Transition Metal-Catalyzed Organometallic Reactions that Have Revolutionized Organic Synthesis. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2007. [DOI: 10.1246/bcsj.80.233] [Citation(s) in RCA: 220] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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60
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Nicolaou KC, Bulger PG, Sarlah D. Palladium-catalyzed cross-coupling reactions in total synthesis. Angew Chem Int Ed Engl 2006; 44:4442-89. [PMID: 15991198 DOI: 10.1002/anie.200500368] [Citation(s) in RCA: 2127] [Impact Index Per Article: 118.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In studying the evolution of organic chemistry and grasping its essence, one comes quickly to the conclusion that no other type of reaction plays as large a role in shaping this domain of science than carbon-carbon bond-forming reactions. The Grignard, Diels-Alder, and Wittig reactions are but three prominent examples of such processes, and are among those which have undeniably exercised decisive roles in the last century in the emergence of chemical synthesis as we know it today. In the last quarter of the 20th century, a new family of carbon-carbon bond-forming reactions based on transition-metal catalysts evolved as powerful tools in synthesis. Among them, the palladium-catalyzed cross-coupling reactions are the most prominent. In this Review, highlights of a number of selected syntheses are discussed. The examples chosen demonstrate the enormous power of these processes in the art of total synthesis and underscore their future potential in chemical synthesis.
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Affiliation(s)
- K C Nicolaou
- Department of Chemistry and Skaggs Institute for Chemical Biology, Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
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62
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A route to 1,2-diols by enantioselective organocatalytic α-oxidation with molecular oxygen. Tetrahedron Lett 2006. [DOI: 10.1016/j.tetlet.2006.04.133] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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63
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Frein JD, Rovis T. Surveying approaches to the formation of carbon-carbon bonds between a pyran and an adjacent ring. Tetrahedron 2006; 62:4573-4583. [PMID: 17710219 PMCID: PMC1950123 DOI: 10.1016/j.tet.2006.02.042] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We have examined several methods for the stereoselective formation of carbon-carbon bonds between contiguous rings where a stereogenic center is already present. The approaches investigated were a [1,3] oxygen to carbon rearrangement of cyclic vinyl acetals, an intermolecular enolsilane addition into an in situ generated oxocarbenium ion, an intramolecular conjugate addition of tethered alkoxy enones, and epimerization of several α-pyranyl cycloalkanones. These routes have been found to be complementary in several cases and have enabled formation of both the trans:anti and cis:anti stereoisomers in good to excellent yields and varying diastereoselectivities. We have proven C2-C2' relative stereochemistry of 1-2 via a chemical correlation.
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Affiliation(s)
- Jeffrey D. Frein
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA
| | - Tomislav Rovis
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA
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64
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Crimmins MT, Zuccarello JL, Cleary PA, Parrish JD. Convergent, stereoselective synthesis of the GHIJ fragment of brevetoxin A. Org Lett 2006; 8:159-62. [PMID: 16381592 DOI: 10.1021/ol0526625] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[reaction: see text] A stereoselective synthesis of the GHIJ fragment of brevetoxin A utilizing a convergent assembly strategy is described. Glycolate alkylation, ring-closing metathesis, and Hosomi-Sakurai reactions were central operations in the construction of the G ring and J ring subunits, which were united through a Horner-Wadsworth-Emmons coupling. Subsequent dehydrative cyclization produced an endocyclic enol ether that was further elaborated to the tetracyclic GHIJ fragment of brevetoxin A.
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Affiliation(s)
- Michael T Crimmins
- Venable and Kenan Laboratories of Chemistry, University of North Carolina at Chapel Hill, 27599, USA.
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65
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Majumder U, Cox JM, Johnson HWB, Rainier JD. Total Synthesis of Gambierol: The Generation of the A–C and F–H Subunits by Using a C-Glycoside Centered Strategy. Chemistry 2006; 12:1736-46. [PMID: 16331718 DOI: 10.1002/chem.200500993] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Gambierol, a representative of the marine ladder toxin family, consists of eight ether rings, 18 stereocenters, and two challenging pyranyl rings having methyl groups that are in a 1,3-diaxial orientation to one another. Herein we describe the generation of gambierol's A-C and F-H ring systems and demonstrate the versatility of the glycosyl anhydride, enol ether-olefin RCM strategy to fused polycyclic ethers. This work has both enabled us to generate sufficient quantities of the gambierol precursors and has enabled us to better understand the chemical transformations that were key to these efforts. Fundamental work included efforts to C-glycosides and C-ketosides, Claisen rearrangements, and enol ether-olefin RCM reactions.
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Affiliation(s)
- Utpal Majumder
- University of Utah, Department of Chemistry, 315 South 1400 East, Salt Lake City, Utah 84112, USA
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66
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Sundén H, Engqvist M, Casas J, Ibrahem I, Córdova A. Direct amino acid catalyzed asymmetric alpha oxidation of ketones with molecular oxygen. Angew Chem Int Ed Engl 2006; 43:6532-5. [PMID: 15578761 DOI: 10.1002/anie.200460295] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Henrik Sundén
- Department of Organic Chemistry, The Arrhenius Laboratory, Stockholm University, Stockholm, Sweden
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67
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Clark JS. Construction of fused polycyclic ethers by strategies involving ring-closing metathesis. Chem Commun (Camb) 2006:3571-81. [PMID: 17047770 DOI: 10.1039/b601839d] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Large fused polycyclic ether natural products of marine origin are some of the most complex and formidable synthetic targets found in Nature, and they continue to fascinate and inspire those engaged in target-directed synthesis and the development of new synthetic methods. Novel strategies for the rapid and stereoselective assembly of fused polyethers have been devised in which ring-closing metathesis reactions are used to accomplish cyclic ether construction. Two-directional and iterative ring construction approaches involving ring-closing metathesis are being employed to assemble polyether sequences found in marine natural products such as the ciguatoxins and gambieric acids.
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Affiliation(s)
- J Stephen Clark
- School of Chemistry, University of Nottingham, University Park, Nottingham, UK NG7 2RD.
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68
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Affiliation(s)
- Masayuki Inoue
- Department of Chemistry and Research and Analytical Center for Giant Molecules, Graduate School of Science, Tohoku University, Sendai, Japan.
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69
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Affiliation(s)
- Tadashi Nakata
- Department of Chemistry, Tokyo University of Science, Shinjuku-ku, Japan.
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70
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Clark JS, Kimber MC, Robertson J, McErlean CSP, Wilson C. Rapid Two-Directional Synthesis of the F-J Fragment of the Gambieric Acids by Iterative Double Ring-Closing Metathesis. Angew Chem Int Ed Engl 2005. [DOI: 10.1002/ange.200501925] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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71
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Clark JS, Kimber MC, Robertson J, McErlean CSP, Wilson C. Rapid Two-Directional Synthesis of the F-J Fragment of the Gambieric Acids by Iterative Double Ring-Closing Metathesis. Angew Chem Int Ed Engl 2005; 44:6157-62. [PMID: 16134189 DOI: 10.1002/anie.200501925] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- J Stephen Clark
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
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72
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Abstract
Our bodies are made of molecules, and it is from molecules that we derive our strength and joys. The joys of molecules manifest themselves in many ways. These include beautiful colors, exquisite aromas, distinct tastes, psychological ups and downs, and intellectual inspirations, among other forms of stimulation, material or spiritual. In this Perspective, written on the occasion of the 2005 American Chemical Society Arthur C. Cope Award address, I recount some of the joys I have experienced and shared with my students during campaigns to synthesize some of Nature's most intriguing and complex molecules.
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Affiliation(s)
- K C Nicolaou
- Department of Chemistry and Skaggs Institute for Chemical Biology, Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
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73
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Crimmins MT, McDougall PJ, Emmitte KA. A Convergent Coupling Strategy for the Formation of Polycyclic Ethers: Stereoselective Synthesis of the BCDE Fragment of Brevetoxin A. Org Lett 2005; 7:4033-6. [PMID: 16119960 DOI: 10.1021/ol051543m] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A stereoselective synthesis of the BCDE fragment of brevetoxin A has been completed. anti-Glycolate aldol, glycolate alkylation, and ring-closing metathesis reactions were employed as key bond-forming events. A convergent assembly strategy was employed that relied on a Horner-Wadsworth-Emmons union of two complex fragments. Subsequent cyclization and dehydration led to efficient generation of an intermediate endocyclic enol ether, which was advanced to a tetracyclic fragment. [reaction: see text]
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Affiliation(s)
- Michael T Crimmins
- Venable and Kenan Laboratories of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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74
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Nicolaou KC, Bulger PG, Sarlah D. Palladiumkatalysierte Kreuzkupplungen in der Totalsynthese. Angew Chem Int Ed Engl 2005. [DOI: 10.1002/ange.200500368] [Citation(s) in RCA: 629] [Impact Index Per Article: 33.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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75
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Larsen US, Martiny L, Begtrup M. Synthesis of 4-substituted tetrahydropyridines by cross-coupling of enol phosphates. Tetrahedron Lett 2005. [DOI: 10.1016/j.tetlet.2005.03.203] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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76
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Watanabe K, Suzuki M, Murata M, Oishi T. Convergent synthesis of the FGHI ring system of yessotoxin: stereoselective construction of the G ring. Tetrahedron Lett 2005. [DOI: 10.1016/j.tetlet.2005.04.040] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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77
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Baden DG, Bourdelais AJ, Jacocks H, Michelliza S, Naar J. Natural and derivative brevetoxins: historical background, multiplicity, and effects. ENVIRONMENTAL HEALTH PERSPECTIVES 2005; 113:621-5. [PMID: 15866774 PMCID: PMC1257558 DOI: 10.1289/ehp.7499] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2004] [Accepted: 02/09/2005] [Indexed: 05/02/2023]
Abstract
Symptoms consistent with inhalation toxicity have long been associated with Florida red tides, and various causal agents have been proposed. Research since 1981 has centered on a group of naturally occurring trans-fused cyclic polyether compounds called brevetoxins that are produced by a marine dinoflagellate known as Karenia brevis. Numerous individual brevetoxins have been identified from cultures as well as from natural bloom events. A spectrum of brevetoxin derivatives produced by chemical modification of the natural toxins has been prepared to examine the effects of functional group modification on physiologic activity. Certain structural features of natural and synthetic derivatives of brevetoxin appear to ascribe specific physiologic consequences to each toxin. Differential physiologic effects have been documented with many of the natural toxins and derivatives, reinforcing the hypothesis that metabolism or modification of toxin structures modulates both the specific toxicity (lethality on a per milligram basis) and potentially the molecular mechanism(s) of action. A series of naturally occurring fused-ring polyether compounds with fewer rings than brevetoxin, known as brevenals, exhibit antagonistic properties and counteract the effects of the brevetoxins in neuronal and pulmonary model systems. Taken together, the inhalation toxicity of Florida red tides would appear to depend on the amount of each toxin present, as well as on the spectrum of molecular activities elicited by each toxin. Toxicity in a bloom is diminished by the amount brevenal present.
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Affiliation(s)
- Daniel G Baden
- University of North Carolina at Wilmington, Center for Marine Science, 5600 Marvin Moss Lane, Wilmington, NC 28409, USA.
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78
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Tsukano C, Ebine M, Sasaki M. Convergent Total Synthesis of Gymnocin-A and Evaluation of Synthetic Analogues. J Am Chem Soc 2005; 127:4326-35. [PMID: 15783214 DOI: 10.1021/ja042686r] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The first total synthesis of gymnocin-A (1), a cytotoxic polycyclic ether isolated from a notorious red tide dinoflagellate, Karenia mikimotoi, has been accomplished. The synthesis relies heavily on the Suzuki-Miyaura cross-coupling-based methodology to assemble the tetradecacyclic polyether skeleton. Convergent union of the GHI (5) and KLMN (6) rings, both of which were prepared from a common intermediate 7, and the subsequent ring closure of the J ring delivered the GHIJKLMN ring. The crucial coupling between the ABCD and FGHIJKLMN ring fragments (3 and 4, respectively) and stereoselective installation of the C17 hydroxyl group, followed by cyclization of the E ring gave rise to the tetradecacyclic polyether skeleton 2. Finally, incorporation of the 2-methyl-2-butenal side chain completed the total synthesis of gymnocin-A. The convergent nature of the synthesis, which employs three fragments of comparable complexity, is well-suited for preparation of various structural analogues of gymnocin-A to explore the structure-activity relationship. The results of preliminary structure-activity relationship studies of several synthetic analogues are also provided.
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Affiliation(s)
- Chihiro Tsukano
- Graduate School of Life Sciences, Tohoku University, Tsutsumidori-amamiya, Aoba-ku, Sendai 981-8555, Japan
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79
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Sundén H, Engqvist M, Casas J, Ibrahem I, Córdova A. Direct Amino Acid Catalyzed Asymmetric α Oxidation of Ketones with Molecular Oxygen. Angew Chem Int Ed Engl 2004. [DOI: 10.1002/ange.200460295] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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80
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Córdova A, Sundén H, Engqvist M, Ibrahem I, Casas J. The direct amino acid-catalyzed asymmetric incorporation of molecular oxygen to organic compounds. J Am Chem Soc 2004; 126:8914-5. [PMID: 15264820 DOI: 10.1021/ja047930t] [Citation(s) in RCA: 192] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have disclosed the direct catalytic incorporation of 1O2 to aldehydes. The unprecedented amino acid-catalyzed asymmetric alpha-oxidation of aldehydes with molecular oxygen or air proceeded with high chemoselectivity and was a direct entry for the synthesis of both enantiomers of terminal diols. The results demonstrated that simple amino acids accomplished catalytic asymmetric oxidations with molecular oxygen or air, which has previously been considered to be in the domain of enzymes and chiral transition-metal complexes. The efficiency of the catalytic process may warrant the existence of an ancient pathway for the synthesis of hydroxylated organic compounds.
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Affiliation(s)
- Armando Córdova
- Department of Organic Chemistry, The Arrhenius Laboratory, Stockholm University, SE-10691 Stockholm, Sweden.
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81
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82
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Oishi T, Watanabe K, Murata M. Convergent synthesis of trans-fused 6/n/6/6 (n=7, 8) tetracyclic ether system via α-cyano ethers. Tetrahedron Lett 2003. [DOI: 10.1016/s0040-4039(03)01862-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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83
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84
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Ferraz HMC, Longo LS. Efficient entry into medium-ring keto-lactones. The ruthenium tetraoxide-promoted oxidative cleavage of beta-hydroxyethers. Org Lett 2003; 5:1337-9. [PMID: 12688753 DOI: 10.1021/ol0342958] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[reaction: see text] A new use of ruthenium tetraoxide is reported. The catalytic oxidative cleavage of hexahydro-benzofuran-3a-ols led to nine-membered ring keto-lactones in moderate to good yields and high purity. The reaction is clean and easily performed using catalytic amounts of ruthenium trichloride and an excess of sodium periodate as a cooxidant.
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Affiliation(s)
- Helena M C Ferraz
- Instituto de Química, Universidade de São Paulo, CEP 05508-900, São Paulo SP, Brazil.
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85
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Coster MJ, De Voss JJ. Medium ring ethers by ring expansion-ring contraction: synthesis of lauthisan. Org Lett 2002; 4:3047-50. [PMID: 12201713 DOI: 10.1021/ol0262946] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[reaction: see text] A new general method for the construction of medium ring ethers has been developed. This involves the ring expansion of halo-O,S-acetals followed by a Ramburg-Bäcklund ring contraction reaction with concomitant extrusion of the sulfur atom. This methodology has been utilized for the synthesis of cis- and trans-lauthisan.
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Affiliation(s)
- Mark J Coster
- Department of Chemistry, University of Queensland, Brisbane 4072, Australia
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86
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Satake M, Shoji M, Oshima Y, Naoki H, Fujita T, Yasumoto T. Gymnocin-A, a cytotoxic polyether from the notorious red tide dinoflagellate, Gymnodinium mikimotoi. Tetrahedron Lett 2002. [DOI: 10.1016/s0040-4039(02)01171-1] [Citation(s) in RCA: 137] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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87
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Synthesis of chiral trans-fused pyrano[3,2-c][2]benzoxocines from d-mannose by regioselective 8-endo-aryl radical cyclization. Tetrahedron Lett 2002. [DOI: 10.1016/s0040-4039(02)01252-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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88
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Candenas M, Pinto FM, Cintado CG, Morales EQ, Brouard I, Dı́az M, Rico M, Rodrı́guez E, Rodrı́guez RM, Pérez R, Pérez RL, Martı́n JD. Synthesis and biological studies of flexible brevetoxin/ciguatoxin models with marked conformational preference. Tetrahedron 2002. [DOI: 10.1016/s0040-4020(02)00047-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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89
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Anderson EA, Davidson JE, Harrison JR, O'Sullivan PT, Burton JW, Collins I, Holmes AB. Synthesis of medium-ring lactones via tandem methylenation/Claisen rearrangement of cyclic carbonates. Tetrahedron 2002. [DOI: 10.1016/s0040-4020(02)00049-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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90
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Preparation of cyclic ethers for polyether synthesis by catalytic ring-closing enyne metathesis of alkynyl ethers. Tetrahedron 2002. [DOI: 10.1016/s0040-4020(02)00053-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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91
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Hirama M, Oishi T, Uehara H, Inoue M, Maruyama M, Oguri H, Satake M. Total synthesis of ciguatoxin CTX3C. Science 2001; 294:1904-7. [PMID: 11729311 DOI: 10.1126/science.1065757] [Citation(s) in RCA: 177] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
More than 20,000 people suffer annually from ciguatera seafood poisoning in subtropical and tropical regions. The extremely low content of the causative neurotoxins, designated as ciguatoxins, in fish has hampered the isolation, detailed biological studies, and preparation of anti-ciguatoxin antibodies for detecting these toxins. The large (3 nanometers long) and complicated molecular structure of ciguatoxins has impeded chemists from completing their total synthesis. Our highly convergent strategic approach featuring the chemoselective ring-closing metathesis reaction as a key tactic has enabled the total synthesis of ciguatoxin CTX3C, which will provide a practical supply for further studies.
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Affiliation(s)
- M Hirama
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.
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92
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Wu J, Yang Z. Nickel-catalyzed cross-couplings of 4-diethylphosphonooxycoumarins with organozinc reagents: an efficient new methodology for the synthesis of 4-substituted coumarins. J Org Chem 2001; 66:7875-8. [PMID: 11701051 DOI: 10.1021/jo010452+] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- J Wu
- Institute of Chemistry and Cell Biology, Harvard Medical School, 250 Longwood Avenue, SGM 604, Boston, Massachusetts 02115-5731, USA
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Nicolaou KC, Mitchell HJ. Adventures in Carbohydrate Chemistry: New Synthetic Technologies, Chemical Synthesis, Molecular Design, and Chemical Biology. Angew Chem Int Ed Engl 2001. [DOI: 10.1002/1521-3773(20010504)40:9<1576::aid-anie15760>3.0.co;2-g] [Citation(s) in RCA: 329] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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94
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Nicolaou KC, Mitchell HJ. Abenteuer in der Kohlenhydratchemie: Synthesestrategien, Synthesemethoden, Moleküldesign und biologische Chemie. Angew Chem Int Ed Engl 2001. [DOI: 10.1002/1521-3757(20010504)113:9<1624::aid-ange16240>3.0.co;2-n] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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95
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Rainier JD, Allwein SP, Cox JM. C-glycosides to fused polycyclic ethers. A formal synthesis of (+/-)-hemibrevetoxin B. J Org Chem 2001; 66:1380-6. [PMID: 11312970 DOI: 10.1021/jo001514j] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This paper describes a formal total synthesis of the marine ladder toxin hemibrevetoxin B from Danishefsky's dienes. This approach couples the generation of C-glycosides from cyclic enol ethers with metathesis or acid-mediated annulation reactions. The result is a highly efficient synthesis of the tetracyclic ring system of hemibrevetoxin B.
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Affiliation(s)
- J D Rainier
- Department of Chemistry, The University of Arizona, Tucson, Arizona 85721, USA.
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96
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Transformation of cis-Epoxy Compound to cis-2,3-Disubstituted Oxane and Investigation on Propagation Step in the Ring-Expansion Reactions of cis,trans-Diepoxy Systems. Tetrahedron 2000. [DOI: 10.1016/s0040-4020(00)00622-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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97
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Abstract
[reaction: see text] This Letter describes the synthesis of the hemibrevetoxin B tetracyclic ring system in 14 linear transformations from the Danishefsky-Kitahara diene.
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Affiliation(s)
- J D Rainier
- Department of Chemistry, The University of Arizona, Tucson 85721, USA.
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Inoue M, Sasaki M, Tachibana K. A convergent synthesis of the trans-fused hexahydrooxonine ring system and reproduction of conformational behavior shown by ring F of ciguatoxin. Tetrahedron 1999. [DOI: 10.1016/s0040-4020(99)00620-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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