1
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Choutka J, Pohl R, Parkan K. MOP and EE Protecting Groups in Synthesis of α- or β-Naphthyl- C-Glycosides from Glycals. ACS OMEGA 2018; 3:7875-7887. [PMID: 31458930 PMCID: PMC6644498 DOI: 10.1021/acsomega.8b00901] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 06/20/2018] [Indexed: 06/10/2023]
Abstract
The development of effective protection strategies is essential in the synthesis of complex carbohydrates and glycomimetics. This article describes a versatile four-stage protocol for the synthesis of α- or β-aryl-C-glycosides from unprotected d-glycals using two acetal protecting groups, ethoxyethyl and methoxypropyl, which are stable under harsh basic conditions and convenient for the C-1 metalation of glycals. Their stability was investigated in subsequent cross-coupling reactions with 1-iodonaphthalene followed by oxidative/reductive transformations to naphthyl-C-glycosides.
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Affiliation(s)
- Jan Choutka
- Department
of Chemistry of Natural Compounds, University
of Chemistry and Technology, Prague, Technická 5, 166 28 Prague, Czech Republic
| | - Radek Pohl
- Institute
of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Gilead Sciences & IOCB Research Center, Flemingovo nám. 2, 166 10 Prague, Czech Republic
| | - Kamil Parkan
- Department
of Chemistry of Natural Compounds, University
of Chemistry and Technology, Prague, Technická 5, 166 28 Prague, Czech Republic
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2
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Affiliation(s)
- You Yang
- Shanghai
Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Biao Yu
- State
Key Laboratory of Bio-organic and Natural Products Chemistry, Shanghai
Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
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3
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Vannam R, Peczuh MW. A practical and scalable synthesis of carbohydrate based oxepines. Org Biomol Chem 2016; 14:3989-96. [PMID: 27056249 DOI: 10.1039/c6ob00262e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An efficient, seven-step synthesis of carbohydrate based oxepines is reported using per-O-acetyl septanoses as key intermediates. The scope of the synthesis was evaluated by varying both the pyranose starting materials and protecting groups incorporated into the oxepine products. The practicality of the method make it amenable to scale up as demonstrated by the gram-scale synthesis of the d-glucose derived oxepine.
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Affiliation(s)
- Raghu Vannam
- Department of Chemistry, University of Connecticut, 55 North Eagleville Road, U-3060, Storrs, CT 06269, USA.
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4
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Wagschal S, Guilbaud J, Rabet P, Farina V, Lemaire S. α-C-Glycosides via syn Opening of 1,2-Anhydro Sugars with Organozinc Compounds in Toluene/n-Dibutyl Ether. J Org Chem 2015; 80:9328-35. [DOI: 10.1021/acs.joc.5b01472] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Simon Wagschal
- Pharmaceutical Development
and Manufacturing Sciences, Janssen Pharmaceutica, Turnhoutseweg 30, B-2340 Beerse, Belgium
| | - Johan Guilbaud
- Pharmaceutical Development
and Manufacturing Sciences, Janssen Pharmaceutica, Turnhoutseweg 30, B-2340 Beerse, Belgium
| | - Pauline Rabet
- Pharmaceutical Development
and Manufacturing Sciences, Janssen Pharmaceutica, Turnhoutseweg 30, B-2340 Beerse, Belgium
| | - Vittorio Farina
- Pharmaceutical Development
and Manufacturing Sciences, Janssen Pharmaceutica, Turnhoutseweg 30, B-2340 Beerse, Belgium
| | - Sébastien Lemaire
- Pharmaceutical Development
and Manufacturing Sciences, Janssen Pharmaceutica, Turnhoutseweg 30, B-2340 Beerse, Belgium
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5
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Affiliation(s)
- Joëlle Prunet
- WestCHEM, Department of Chemistry, University of Glasgow, Joseph Black Building, University Avenue, Glasgow G12 8QQ, UK, Fax: +44‐141‐330‐4888
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6
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Abstract
Maitotoxin holds a special place in the annals of natural products chemistry as the largest and most toxic secondary metabolite known to date. Its fascinating, ladder-like, polyether molecular structure and diverse spectrum of biological activities elicited keen interest from chemists and biologists who recognized its uniqueness and potential as a probe and inspiration for research in chemistry and biology. Synthetic studies in the area benefited from methodologies and strategies that were developed as part of chemical synthesis programs directed toward the total synthesis of some of the less complex members of the polyether marine biotoxin class, of which maitotoxin is the flagship. This account focuses on progress made in the authors' laboratories in the synthesis of large maitotoxin domains with emphasis on methodology development, strategy design, and structural comparisons of the synthesized molecules with the corresponding regions of the natural product. The article concludes with an overview of maitotoxin's biological profile and future perspectives.
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Affiliation(s)
- K. C. Nicolaou
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037 (USA), Fax: (+1) 858-784-2469, and Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093 (USA)
| | - Robert J. Aversa
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037 (USA), Fax: (+1) 858-784-2469, and Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093 (USA)
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7
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Nicolaou KC, Baker TM, Nakamura T. Synthesis of the WXYZA' domain of maitotoxin. J Am Chem Soc 2010; 133:220-6. [PMID: 21166430 DOI: 10.1021/ja109533y] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A synthesis of the WXYZA' domain (7) of the marine neurotoxin maitotoxin (1) is reported. The convergent synthetic strategy involves construction of key building blocks 11 and 12, their coupling, and the elaboration of the resulting ester (10) to the target molecule through a ring-closing metathesis and a hydroxy dithioketal cyclization as the key steps. For the construction of fragment 11, the Noyori reduction/Achmatowicz rearrangement and hydroxy epoxide opening technologies were applied (starting from furfuryl alcohol (13)), whereas for the synthesis of fragment 12, a carbohydrate-based approach was adopted (starting from 2-deoxy-D-ribose (14)). The synthesized WXYZA' domain (7) of maitotoxin (1) exhibited the expected (13)C NMR chemical shifts, supporting the originally assigned structure of the corresponding region of the natural product.
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Affiliation(s)
- K C Nicolaou
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States.
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8
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Fuwa H. Total Synthesis of Structurally Complex Marine Oxacyclic Natural Products. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2010. [DOI: 10.1246/bcsj.20100209] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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10
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Gómez AM, Pedregosa A, Casillas M, Uriel C, López JC. Synthesis ofC-1 Alkyl and Aryl Glycals from Pyranosyl or Furanosyl Chlorides by Treatment with Organolithium Reagents. European J Org Chem 2009. [DOI: 10.1002/ejoc.200900417] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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11
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Abstract
The last one hundred years have witnessed a dramatic increase in the power and reach of total synthesis. The pantheon of accomplishments in the field includes the total synthesis of molecules of unimaginable beauty and diversity such as the four discussed in this article: endiandric acids (1982), calicheamicin gamma(1)(I) (1992), Taxol (1994), and brevetoxin B (1995). Chosen from the collection of the molecules synthesized in the author's laboratories, these structures are but a small fraction of the myriad constructed in laboratories around the world over the last century. Their stories, and the background on which they were based, should serve to trace the evolution of the art of chemical synthesis to its present sharp condition, an emergence that occurred as a result of new theories and mechanistic insights, new reactions, new reagents and catalysts, and new synthetic technologies and strategies. Indeed, the advent of chemical synthesis as a whole must be considered as one of the most influential developments of the twentieth century in terms of its impact on society.
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Affiliation(s)
- K C Nicolaou
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
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12
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Sheldrake HM, Jamieson C, Pascu SI, Burton JW. Synthesis of the originally proposed structures of elatenyne and an enyne from Laurencia majuscula. Org Biomol Chem 2009; 7:238-52. [DOI: 10.1039/b814953d] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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Saito T, Nakata T. Stereoselective Synthesis of trans-Fused 7,6,6,7-Membered Tetracyclic Ether, Corresponding to the EFGH-Ring of Gambierol and the BCDE-Ring of Gambieric Acids. Org Lett 2008; 11:113-6. [DOI: 10.1021/ol8024555] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tatsuo Saito
- Department of Chemistry, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan
| | - Tadashi Nakata
- Department of Chemistry, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan
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Linker T, Schanzenbach D, Elamparuthi E, Sommermann T, Fudickar W, Gyóllai V, Somsák L, Demuth W, Schmittel M. Remarkable Oxidation Stability of Glycals: Excellent Substrates for Cerium(IV)-Mediated Radical Reactions. J Am Chem Soc 2008; 130:16003-10. [DOI: 10.1021/ja8052706] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Torsten Linker
- Department of Chemistry, University of Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Potsdam, Germany, Department of Organic Chemistry, University of Debrecen, P.O. Box 20, H-4010 Debrecen, Hungary, and Department of Chemistry, University of Siegen, Adolf Reichwein Strasse 2, D-57068 Siegen, Germany
| | - Dirk Schanzenbach
- Department of Chemistry, University of Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Potsdam, Germany, Department of Organic Chemistry, University of Debrecen, P.O. Box 20, H-4010 Debrecen, Hungary, and Department of Chemistry, University of Siegen, Adolf Reichwein Strasse 2, D-57068 Siegen, Germany
| | - Elangovan Elamparuthi
- Department of Chemistry, University of Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Potsdam, Germany, Department of Organic Chemistry, University of Debrecen, P.O. Box 20, H-4010 Debrecen, Hungary, and Department of Chemistry, University of Siegen, Adolf Reichwein Strasse 2, D-57068 Siegen, Germany
| | - Thomas Sommermann
- Department of Chemistry, University of Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Potsdam, Germany, Department of Organic Chemistry, University of Debrecen, P.O. Box 20, H-4010 Debrecen, Hungary, and Department of Chemistry, University of Siegen, Adolf Reichwein Strasse 2, D-57068 Siegen, Germany
| | - Werner Fudickar
- Department of Chemistry, University of Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Potsdam, Germany, Department of Organic Chemistry, University of Debrecen, P.O. Box 20, H-4010 Debrecen, Hungary, and Department of Chemistry, University of Siegen, Adolf Reichwein Strasse 2, D-57068 Siegen, Germany
| | - Viktor Gyóllai
- Department of Chemistry, University of Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Potsdam, Germany, Department of Organic Chemistry, University of Debrecen, P.O. Box 20, H-4010 Debrecen, Hungary, and Department of Chemistry, University of Siegen, Adolf Reichwein Strasse 2, D-57068 Siegen, Germany
| | - László Somsák
- Department of Chemistry, University of Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Potsdam, Germany, Department of Organic Chemistry, University of Debrecen, P.O. Box 20, H-4010 Debrecen, Hungary, and Department of Chemistry, University of Siegen, Adolf Reichwein Strasse 2, D-57068 Siegen, Germany
| | - Wolfgang Demuth
- Department of Chemistry, University of Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Potsdam, Germany, Department of Organic Chemistry, University of Debrecen, P.O. Box 20, H-4010 Debrecen, Hungary, and Department of Chemistry, University of Siegen, Adolf Reichwein Strasse 2, D-57068 Siegen, Germany
| | - Michael Schmittel
- Department of Chemistry, University of Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Potsdam, Germany, Department of Organic Chemistry, University of Debrecen, P.O. Box 20, H-4010 Debrecen, Hungary, and Department of Chemistry, University of Siegen, Adolf Reichwein Strasse 2, D-57068 Siegen, Germany
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15
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Osei Akoto C, Rainier J. Harnessing Glycal-Epoxide Rearrangements: The Generation of the AB, EF, and IJ Rings of Adriatoxin. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200803791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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16
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Lemoine P, Daoust B. Water as an efficient medium for the synthesis of functionalized enol ethers. Tetrahedron Lett 2008. [DOI: 10.1016/j.tetlet.2008.07.165] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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17
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Nicolaou K, Frederick M, Aversa R. Die Entdeckung und Synthese von marinen Polyethern. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200801696] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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18
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Mao S, Probst D, Werner S, Chen J, Xie X, Brummond KM. Diverging Rh(I)-catalyzed carbocylization strategy to prepare a library of unique cyclic ethers. ACTA ACUST UNITED AC 2008; 10:235-46. [PMID: 18271514 DOI: 10.1021/cc7001843] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A library of 90 carboxamide-containing oxepines and pyrans was synthesized. A dual-branching strategy was used where a common intermediate, an allenyl-hydroxy ester, was either allylated or propargylated then subjected to rhodium(I)-catalyzed carbocyclization reaction conditions to afford an oxepine- or triene-containing pyran, respectively. The oxepines were selectively reduced to afford two functionally unique scaffolds using complementary hydrogenation conditions. Diversification of the oxepines and pyrans involved conversion of the methyl carboxylate group to a carboxamide via either a microwave-assisted amidation using polymer-bound carbodiimide (DCC) and 1-hydroxybenzotriazole (HOBt) or a NaCN-catalyzed aminolysis. The scope of a rarely used carbonyl-yne reaction was expanded to the preparation of 10 new allenyl-hydroxy esters using microwave irradiation. Finally, a cell-based diversity analysis using BCUT (Burden (B) CAS (C) Pearlman at the University of Texas (UT)) metrics calculations and two-dimensional fingerprint similarity approaches shows that when compared to the 100,000 Pittsburgh Molecular Library Screening Center (PMLSC) compound database and PubChem the new compound library occupies a unique chemical space.
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Affiliation(s)
- Shuli Mao
- University of Pittsburgh Center for Chemical Methodologies & Library Development and Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
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19
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Sasaki M, Fuwa H. Convergent strategies for the total synthesis of polycyclic ether marine metabolites. Nat Prod Rep 2008; 25:401-26. [PMID: 18389143 DOI: 10.1039/b705664h] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Marine polycyclic ether natural products continue to fascinate chemists and biologists due to their exceptionally large and complex molecular architectures and potent and diverse biological activities. Tremendous progress has been made over the past decade toward the total synthesis of marine polycyclic ether natural products. In this area, a convergent strategy for assembling small fragments into an entire molecule always plays a key role in successful total synthesis. This review describes our efforts to develop convergent strategies for the synthesis of polycyclic ethers and their application to the total synthesis of gambierol, gymnocin-A, and brevenal, and to the partial synthesis of the central part of ciguatoxins and the nonacyclic polyether skeleton of gambieric acids.
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Affiliation(s)
- Makoto Sasaki
- Laboratory of Biostructural Chemistry, Graduate School of Life Sciences, Tohoku University, 1-1 Tsutsumidori-amamiya, Aoba-ku, Sendai 981-8555, Japan.
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20
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Abstract
The unprecedented structure of the marine natural product brevetoxin B was elucidated by the research group of Nakanishi and Clardy in 1981. The ladderlike molecular architecture of this fused polyether molecule, its potent toxicity, and fascinating voltage-sensitive sodium channel based mechanism of action immediately captured the imagination of synthetic chemists. Synthetic endeavors resulted in numerous new methods and strategies for the construction of cyclic ethers, and culminated in several impressive total syntheses of this molecule and some of its equally challenging siblings. Of the marine polyethers, maitotoxin is not only the most complex and most toxic of the class, but is also the largest nonpolymeric natural product known to date. This Review begins with a brief history of the isolation of these biotoxins and highlights their biological properties and mechanism of action. Chemical syntheses are then described, with particular emphasis on new methods developed and applied to the total syntheses. The Review ends with a discussion of the, as yet unfinished, story of maitotoxin, and projects into the future of this area of research.
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Affiliation(s)
- K C Nicolaou
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
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21
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Akoto CO, Rainier JD. Harnessing glycal-epoxide rearrangements: the generation of the AB, EF, and IJ rings of adriatoxin. Angew Chem Int Ed Engl 2008; 47:8055-8. [PMID: 18785198 PMCID: PMC2597071 DOI: 10.1002/anie.200803791] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Clement Osei Akoto
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, UT 84112, USA
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Roberts SW, Rainier JD. Synthesis of an A-E gambieric acid subunit with use of a C-glycoside centered strategy. Org Lett 2007; 9:2227-30. [PMID: 17469838 DOI: 10.1021/ol0707970] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This paper describes our synthesis of the A-E subunit of gambieric acid (GA) in addition to the synthesis of the A-ring and the C-E tricycle. The use of an enol ether-olefin RCM strategy to couple the A and C-E subunits and, in the process, generate the B-ring is noteworthy.
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Affiliation(s)
- Scott W Roberts
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, USA
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24
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Brass S, Chan NS, Gerlach C, Luksch T, Böttcher J, Diederich WE. Synthesis of 2,3,4,7-tetrahydro-1H-azepines as privileged ligand scaffolds for the design of aspartic protease inhibitors via a ring-closing metathesis approach. J Organomet Chem 2006. [DOI: 10.1016/j.jorganchem.2006.09.031] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
With the exception of palladium-catalyzed cross-couplings, no other group of reactions has had such a profound impact on the formation of carbon-carbon bonds and the art of total synthesis in the last quarter of a century than the metathesis reactions of olefins, enynes, and alkynes. Herein, we highlight a number of selected examples of total syntheses in which such processes played a crucial role and which imparted to these endeavors certain elements of novelty, elegance, and efficiency. Judging from their short but impressive history, the influence of these reactions in chemical synthesis is destined to increase.
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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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27
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De Matteis V, van Delft FL, Tiebes J, Rutjes FPJT. A Ring-Closing Metathesis Pathway to Fluorovinyl-Containing Nitrogen Heterocyles. European J Org Chem 2006. [DOI: 10.1002/ejoc.200500826] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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28
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Abstract
The preceding manuscript detailed our synthesis of the gambierol A-C and F-H ring precursors. Reported herein is a description of the coupling of the two precursors and the conversion of the coupled material into gambierol. Coupling of the subunits involved ester formation, enol ether RCM, and mixed thioketal formation and reduction. By employing this strategy we were able to bring highly advanced subunits into the coupling and, as a result, we were able to minimize the number of post-coupling transformations required to complete gambierol. At the completion of the synthesis, we generated 7.5 mg (1.5 % overall yield) of (-)-gambierol in 44 steps (longest linear sequence).
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Affiliation(s)
- Henry W B Johnson
- University of Utah, Department of Chemistry, 315 South 1400 East, Salt Lake City, Utah 84112, USA
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29
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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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31
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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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Nosse B, Schall A, Jeong W, Reiser O. Optimization of Ring-Closing Metathesis: Inert Gas Sparging and Microwave Irradiation. Adv Synth Catal 2005. [DOI: 10.1002/adsc.200505137] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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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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Affiliation(s)
- Tadashi Nakata
- Department of Chemistry, Tokyo University of Science, Shinjuku-ku, Japan.
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35
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Majumder U, Rainier JD. Olefinic-ester cyclizations using Takai–Utimoto reduced titanium alkylidenes. Tetrahedron Lett 2005. [DOI: 10.1016/j.tetlet.2005.08.071] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Xie J, Ménand M, Valéry JM. Regioselective debenzylation of C-glycosyl compounds by boron trichloride. Carbohydr Res 2005; 340:481-7. [PMID: 15680604 DOI: 10.1016/j.carres.2004.12.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2004] [Revised: 11/17/2004] [Accepted: 12/02/2004] [Indexed: 10/26/2022]
Abstract
Boron trichloride has been found to promote selective deprotection of 1,2- or 1,3-cis oriented secondary benzyl ethers of per-benzylated C-glycosyl derivatives. The reactivity towards BCl(3) follows the order: C-4>or=C-2>C-6>C-3 for C-glucopyranosyl derivatives and C-3>or=C-4>C-6>C-2 for C-galactopyranosyl derivatives. Preparatively useful selective debenzylation at secondary positions was possible after careful control of reaction conditions.
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Affiliation(s)
- Juan Xie
- Synthèse, Structure et Fonction des Molécules Bioactives, CNRS UMR 7613, Equipe Chimie des Glucides, Université Pierre et Marie Curie, 4 Place Jussieu, F-75005 Paris, France.
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37
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Abstract
A fully functionalized ABCD ring moiety of gambierol, a marine polycyclic ether toxin, was synthesized by the use of the oxiranyl anion strategy and reductive cycloetherification of a beta,delta-dihydroxy ketone.
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Affiliation(s)
- Hiroki Furuta
- Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku, Nagoya 468-8503, Japan
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38
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39
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Nishiguchi GA, Little RD. From C-Glycosides to Pyranopyrans: An Approach to Thyrsiferol Using Titanium(III)-Promoted Redox Couplings. J Org Chem 2005; 70:5249-56. [PMID: 15960529 DOI: 10.1021/jo050465d] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An approach to the pyranopyran ring system that is found in many natural products, including thyrsiferol, is described. The route entails the assembly of an alpha,beta-unsaturated ketone (11) from geraniol and dihydropyran (23) from acetyl acetaldehyde dimethyl acetal (19) and their titanium(III)-promoted coupling to afford a respectable 60% yield of keto alcohol 26. The sigma-bond formed in this process corresponds to the pro-C(9)-C(10) bond of thyrsiferol (4). Attempts to invert the stereochemistry at the pro-C(11) center were thwarted by the congestion imparted by the presence of the vicinal TBS-ether. Consequently, cyclization of the coupling adduct under conditions developed by Olah and Prakash and co-workers led to the cis-fused pyranopyran 27. X-ray analysis of this crystalline material confirmed each of the stereochemical assignments. After much effort, it was determined that the hydroxyl group at C(12) could be removed by treating the derived methyl xanthate with a tri-n-butylphosphine-borane complex under radical-forming conditions. The reaction sequence worked well, despite the hindered working environment and the presence of a potentially labile C-Br bond.
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Affiliation(s)
- Gisele A Nishiguchi
- Department of Chemistry & Biochemistry, University of California, Santa Barbara, CA 93106, USA
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40
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Castro S, Peczuh MW. Sequential Cyclization−Elimination Route to Carbohydrate-Based Oxepines. J Org Chem 2005; 70:3312-5. [PMID: 15823004 DOI: 10.1021/jo048128c] [Citation(s) in RCA: 22] [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
A five-step preparation of carbohydrate-based oxepines from hept-1-enitols is presented. The hept-1-enitols were subjected to silyl protection and hydroboration/oxidation to give the protected heptan-1-itols. Swern oxidation of the homologated alcohols followed by sequential acetal formation/cyclization provided methyl 2-deoxyseptanosides that underwent elimination reactions to give the carbohydrate-based oxepines. The new sequence is an alternative to the ring-closing metathesis for the synthesis of carbohydrate-based oxepines from protected pyranose sugars. The product oxepines can serve as glycosyl donors in the synthesis of novel septanose carbohydrates. In addition, C-methylenealdehydo arabinofuranoside 16 was formed from 2-deoxyseptanoside 10 as the only product during protic acid mediated elimination reactions. This novel ring contraction complements other reported preparations of C-methylenaldehydo furanosides and underscores the acid-mediated reactivity introduced by competing eliminations between the C-1/C-2 and C-2/C-3 bonds.
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Affiliation(s)
- Steve Castro
- Department of Chemistry, The University of Connecticut, 55 North Eagleville Road, U-3060, Storrs, CT 06269, USA
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41
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Roberts SW, Rainier JD. Substitution and Remote Protecting Group Influence on the Oxidation/Addition of α-Substituted 1,2-Anhydroglycosides: A Novel Entry into C-Ketosides. Org Lett 2005; 7:1141-4. [PMID: 15760159 DOI: 10.1021/ol0501469] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[reaction: see text] C-Ketosides are valuable intermediates in chemical synthesis and as glycoside mimics. This manuscript describes the efficient generation of these substrates from alpha-alkyl-substituted glycals and an oxidative, C-C bond-forming sequence where the choice of C(3) protecting group was critical.
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Affiliation(s)
- Scott W Roberts
- Department of Chemistry, University of Utah, 315 S 1400 E, Salt Lake City, Utah 84112, USA
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42
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Abstract
An overview of marine natural products synthesis during 2003 is provided. The emphasis on total syntheses of molecules of contemporary interest, new total syntheses, and syntheses that have resulted in structure conformation or stereochemical assignments.
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43
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Abstract
This communication describes the total synthesis of the marine polyether toxin, gambierol. This work couples our iterative C-glycoside/enol ether-olefin metathesis strategy to the subunits with a unique olefin metathesis/carbonyl olefination reaction to bring the subunits together.
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Affiliation(s)
- Henry W B Johnson
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, USA
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44
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45
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Synthesis of C1-alkyl- and acylglycals from glycals using a B-alkyl Suzuki–Miyaura cross coupling approach. Tetrahedron Lett 2004. [DOI: 10.1016/j.tetlet.2003.12.006] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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46
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Kadota I, Takamura H, Sato K, Ohno A, Matsuda K, Satake M, Yamamoto Y. Convergent Total Syntheses of Gambierol and 16-epi-Gambierol and Their Biological Activities. J Am Chem Soc 2003; 125:11893-9. [PMID: 14505411 DOI: 10.1021/ja036984k] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The convergent total syntheses of gambierol (1) and 16-epi-gambierol (2) have been achieved. The ABC and FGH ring segments 4 and 5 were prepared from known compounds 6 and 13, respectively, by linear manners. The fragments prepared were connected by our own synthetic strategy including the intramolecular allylation of alpha-acetoxy ether followed by ring-closing metathesis to furnish the octacyclic ether 3. The diiodoalkene 45, prepared from 3, was converted to the Z-iodoalkene 50 via a novel and stereoselective hydrogenolysis followed by deprotection. Construction of the triene side chain was performed by the modified Stille coupling of 50 with the Z-vinylic stannane 41 to afford 1. The similar transformations were carried out on the epimeric octacycle 34 to give 2, which showed no toxicity against mice at the concentration of 14 mg/kg.
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Affiliation(s)
- Isao Kadota
- Research Center for Sustainable Materials Engineering, Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8578, Japan.
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47
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Fuwa H, Kainuma N, Satake M, Sasaki M. Synthesis and biological evaluation of gambierol analogues. Bioorg Med Chem Lett 2003; 13:2519-22. [PMID: 12852956 DOI: 10.1016/s0960-894x(03)00467-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Gambierol is a polycyclic ether toxin, isolated as a toxic constituent from the marine dinoflagellate Gambierdiscus toxicus. We describe here the synthesis and biological evaluation of structural analogues of gambierol. The present preliminary structure-activity relationship studies clearly indicate that the H ring functionality and the unsaturated side chain of gambierol are crucial for its potent toxicity.
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Affiliation(s)
- Haruhiko Fuwa
- Graduate School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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48
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Peczuh MW, Snyder NL. Carbohydrate-based oxepines: ring expanded glycals for the synthesis of septanose saccharides. Tetrahedron Lett 2003. [DOI: 10.1016/s0040-4039(03)00849-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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