1
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Affiliation(s)
- Carmen Nájera
- Centro de Innovación en Química Avanzada (ORFEO−CINQA), Universidad de Alicante, Apdo. 99, Alicante E-03080, Spain
| | - Leiv K. Sydnes
- Department of Chemistry, University of Bergen, Allégt. 41, Bergen NO-5007, Norway
| | - Miguel Yus
- Centro de Innovación en Química Avanzada (ORFEO−CINQA), Universidad de Alicante, Apdo. 99, Alicante E-03080, Spain
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2
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Ghosh A, Brueckner AC, Cheong PHY, Carter RG. Second-Generation Synthesis of the Northern Fragment of Mandelalide A: Role of π-Stacking on Sharpless Dihydroxylation of cis-Enynes. J Org Chem 2019; 84:9196-9214. [PMID: 31264876 DOI: 10.1021/acs.joc.9b01153] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The development of a π-stacking-based approach for increased stereoselectivity in Sharpless asymmetric and diastereomeric dihydroxylation of cis-enynes is disclosed. The use of neighboring, electron-rich benzoate esters proved key to the success of this process. Density functional theory study suggests that the substrate benzoate ester group rigidifies the dihydroxylation transition states by forming a favorable π-stacking interaction in both Major-TS and Minor-TS. The energetic preference for the Major-TS was found in part because of the favorable eclipsing conformation of the alkene substituent as opposed to the disfavored bisecting conformation found in the Minor-TS. The application to a second-generation synthesis of the C15-C24 northern portion of mandelalide A is demonstrated.
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Affiliation(s)
- Ankan Ghosh
- Department of Chemistry , Oregon State University , Corvallis , Oregon 97331 , United States
| | - Alexander C Brueckner
- Department of Chemistry , Oregon State University , Corvallis , Oregon 97331 , United States
| | - Paul Ha-Yeon Cheong
- Department of Chemistry , Oregon State University , Corvallis , Oregon 97331 , United States
| | - Rich G Carter
- Department of Chemistry , Oregon State University , Corvallis , Oregon 97331 , United States
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3
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Zhang Z, Chen Y, Adu-Ampratwum D, Okumu AA, Kenton NT, Forsyth CJ. Synthesis of the C22–C40 Domain of the Azaspiracids. Org Lett 2016; 18:1824-7. [DOI: 10.1021/acs.orglett.6b00557] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Zhigao Zhang
- Department
of Chemistry and
Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Yong Chen
- Department
of Chemistry and
Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Daniel Adu-Ampratwum
- Department
of Chemistry and
Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Antony Akura Okumu
- Department
of Chemistry and
Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Nathaniel T. Kenton
- Department
of Chemistry and
Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Craig J. Forsyth
- Department
of Chemistry and
Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
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4
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Mahapatra S, Carter RG. Exploiting hidden symmetry in natural products: total syntheses of amphidinolides C and F. J Am Chem Soc 2013; 135:10792-803. [PMID: 23845005 PMCID: PMC3786714 DOI: 10.1021/ja404796n] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The total synthesis of amphidinolide C and a second-generation synthesis of amphidinolide F have been accomplished through the use of a common intermediate to access both the C1-C8 and the C18-C25 sections. The development of a Ag-catalyzed cyclization of a propargyl benzoate diol is described to access both trans-tetrahydrofuran rings. The evolution of a Felkin-controlled, 2-lithio-1,3-dienyl addition strategy to incorporate C9-C11 diene as well as C8 stereocenter is detailed. Key controlling aspects in the sulfone alkylation/oxidative desulfurization to join the major subunits, including the exploration of the optimum masking group for the C18 carbonyl motif, are discussed. A Trost asymmetric alkynylation and a stereoselective cuprate addition to an alkynoate have been developed for the rapid construction of the C26-C34 subunit. A Tamura/Vedejs olefination to introduce the C26 side arm of amphidnolides C and F is employed. The late-stage incorporation of the C15, C18 diketone motif proved critical to the successful competition of the total syntheses.
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Affiliation(s)
- Subham Mahapatra
- Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, USA
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5
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Fandrick DR, Reeves JT, Bakonyi JM, Nyalapatla PR, Tan Z, Niemeier O, Akalay D, Fandrick KR, Wohlleben W, Ollenberger S, Song JJ, Sun X, Qu B, Haddad N, Sanyal S, Shen S, Ma S, Byrne D, Chitroda A, Fuchs V, Narayanan BA, Grinberg N, Lee H, Yee N, Brenner M, Senanayake CH. Zinc Catalyzed and Mediated Asymmetric Propargylation of Trifluoromethyl Ketones with a Propargyl Boronate. J Org Chem 2013; 78:3592-615. [DOI: 10.1021/jo400080y] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Daniel R. Fandrick
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury
Rd./PO BOX 368, Ridgefield, Connecticut 06877-0368, United States
| | - Jonathan T. Reeves
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury
Rd./PO BOX 368, Ridgefield, Connecticut 06877-0368, United States
| | - Johanna M. Bakonyi
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury
Rd./PO BOX 368, Ridgefield, Connecticut 06877-0368, United States
| | - Prasanth R. Nyalapatla
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury
Rd./PO BOX 368, Ridgefield, Connecticut 06877-0368, United States
| | - Zhulin Tan
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury
Rd./PO BOX 368, Ridgefield, Connecticut 06877-0368, United States
| | - Oliver Niemeier
- Boehringer Ingelheim GmbH & Co KG, Binger Strasse 173, 55216 Ingelheim am Rhein, Germany
| | - Deniz Akalay
- Boehringer Ingelheim GmbH & Co KG, Binger Strasse 173, 55216 Ingelheim am Rhein, Germany
| | - Keith R. Fandrick
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury
Rd./PO BOX 368, Ridgefield, Connecticut 06877-0368, United States
| | - Wolfgang Wohlleben
- Boehringer Ingelheim GmbH & Co KG, Binger Strasse 173, 55216 Ingelheim am Rhein, Germany
| | - Swetlana Ollenberger
- Boehringer Ingelheim GmbH & Co KG, Binger Strasse 173, 55216 Ingelheim am Rhein, Germany
| | - Jinhua J. Song
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury
Rd./PO BOX 368, Ridgefield, Connecticut 06877-0368, United States
| | - Xiufeng Sun
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury
Rd./PO BOX 368, Ridgefield, Connecticut 06877-0368, United States
| | - Bo Qu
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury
Rd./PO BOX 368, Ridgefield, Connecticut 06877-0368, United States
| | - Nizar Haddad
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury
Rd./PO BOX 368, Ridgefield, Connecticut 06877-0368, United States
| | - Sanjit Sanyal
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury
Rd./PO BOX 368, Ridgefield, Connecticut 06877-0368, United States
| | - Sherry Shen
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury
Rd./PO BOX 368, Ridgefield, Connecticut 06877-0368, United States
| | - Shengli Ma
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury
Rd./PO BOX 368, Ridgefield, Connecticut 06877-0368, United States
| | - Denis Byrne
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury
Rd./PO BOX 368, Ridgefield, Connecticut 06877-0368, United States
| | - Ashish Chitroda
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury
Rd./PO BOX 368, Ridgefield, Connecticut 06877-0368, United States
| | - Victor Fuchs
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury
Rd./PO BOX 368, Ridgefield, Connecticut 06877-0368, United States
| | - Bikshandarkoil A. Narayanan
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury
Rd./PO BOX 368, Ridgefield, Connecticut 06877-0368, United States
| | - Nelu Grinberg
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury
Rd./PO BOX 368, Ridgefield, Connecticut 06877-0368, United States
| | - Heewon Lee
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury
Rd./PO BOX 368, Ridgefield, Connecticut 06877-0368, United States
| | - Nathan Yee
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury
Rd./PO BOX 368, Ridgefield, Connecticut 06877-0368, United States
| | - Michael Brenner
- Boehringer Ingelheim GmbH & Co KG, Binger Strasse 173, 55216 Ingelheim am Rhein, Germany
| | - Chris H. Senanayake
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury
Rd./PO BOX 368, Ridgefield, Connecticut 06877-0368, United States
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6
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Lu L, Zhang W, Nam S, Horne DA, Jove R, Carter RG. Amphidinolide B: total synthesis, structural investigation, and biological evaluation. J Org Chem 2013; 78:2213-47. [PMID: 23406192 PMCID: PMC3631602 DOI: 10.1021/jo3026077] [Citation(s) in RCA: 20] [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
The total syntheses of amphidinolide B1 and the proposed structure of amphidinolide B2 have been accomplished. Key aspects of this work include the development of a practical, non-transition-metal-mediated method for the construction of the C13-C15 diene, the identification of α-chelation and dipole minimization models for diastereoselective methyl ketone aldol reactions, the discovery of a spontaneous Horner-Wadsworth-Emmons macrocyclization strategy, and the development of a novel late stage method for construction of an allylic epoxide moiety. The originally proposed structure for amphidinolide B2 and diastereomers thereof display potent antitumor activities with IC50 values ranging from 3.3 to 94.5 nM against human solid and blood tumor cells. Of the different stereoisomers, the proposed structure of amphidinolide B2 is over 12-fold more potent than the C8,9-epimer and C18-epimer in human DU145 prostate cancer cells. These data suggest that the epoxide stereochemistry is a significant factor for anticancer activity.
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Affiliation(s)
- Liang Lu
- Department of Chemistry, Oregon State University, Corvallis, OR 97331
| | - Wei Zhang
- Department of Chemistry, Oregon State University, Corvallis, OR 97331
| | - Sangkil Nam
- Department of Molecular Medicine, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA
| | - David A. Horne
- Department of Molecular Medicine, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA
| | - Richard Jove
- Department of Molecular Medicine, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA
| | - Rich G. Carter
- Department of Chemistry, Oregon State University, Corvallis, OR 97331
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7
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Peng Z, Takenaka N. Applications of Helical-Chiral Pyridines as Organocatalysts in Asymmetric Synthesis. CHEM REC 2012; 13:28-42. [DOI: 10.1002/tcr.201200010] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Indexed: 11/09/2022]
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8
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9
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Friedemann NM, Härter A, Brandes S, Groß S, Gerlach D, Münch W, Schollmeyer D, Nubbemeyer U. Zwitterionic Aza-Claisen Rearrangements Controlled by Pyrrolidine Auxiliaries - Useful Key Steps in Convergent Enantioselective Syntheses. European J Org Chem 2012. [DOI: 10.1002/ejoc.201200073] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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10
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Reddy LR. Chiral Brønsted Acid Catalyzed Enantioselective Propargylation of Aldehydes with Allenylboronate. Org Lett 2012; 14:1142-5. [DOI: 10.1021/ol300075n] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Leleti Rajender Reddy
- Chemical and Analytical Development, Novartis Pharmaceutical Corporation, East Hanover, New Jersey 07936, United States
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11
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12
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Fandrick KR, Fandrick DR, Reeves JT, Gao J, Ma S, Li W, Lee H, Grinberg N, Lu B, Senanayake CH. A general copper-BINAP-catalyzed asymmetric propargylation of ketones with propargyl boronates. J Am Chem Soc 2011; 133:10332-5. [PMID: 21639096 DOI: 10.1021/ja2028958] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
An operationally simple copper-BINAP-catalyzed, highly enantioselective propargylation of ketones is presented. The methodology was developed as an enantioselective process for methyl ethyl ketone and shown to be applicable to a wide variety of prochiral ketones. The resulting homopropargyl adducts are versatile latent carbonyls from which γ-butyrolactones, β-hydroxy methyl ketones, and β-hydroxycarboxylates are readily obtained.
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Affiliation(s)
- Keith R Fandrick
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury Road/P.O. Box 368, Ridgefield, Connecticut 06877-0368, USA.
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13
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Trost BM, Ngai MY, Dong G. Ligand-accelerated enantioselective propargylation of aldehydes via allenylzinc reagents. Org Lett 2011; 13:1900-3. [PMID: 21391717 DOI: 10.1021/ol200043n] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
An enantioselective propargylation of aldehydes using an allenylzinc reagent generated in situ via a zinc-iodine exchange reaction is described. The enantioselectivity is controlled by addition of a catalytic amount of readily accessible and highly tunable amino alcohol ligand L13. A wide range of aldehydes can be propargylated to afford valuable and versatile homopropargyl alcohols in good to excellent yields with high levels of enantiopurity.
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Affiliation(s)
- Barry M Trost
- Department of Chemistry, Stanford University, Stanford, California 94305, USA.
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14
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Chen J, Captain B, Takenaka N. Helical Chiral 2,2′-Bipyridine N- Monoxides as Catalysts in the Enantioselective Propargylation of Aldehydes with Allenyltrichlorosilane. Org Lett 2011; 13:1654-7. [DOI: 10.1021/ol200102c] [Citation(s) in RCA: 120] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Jinshui Chen
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146-0431, United States
| | - Burjor Captain
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146-0431, United States
| | - Norito Takenaka
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146-0431, United States
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15
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Bartoli G, Marcantoni E, Marcolini M, Sambri L. Applications of CeCl(3) as an environmental friendly promoter in organic chemistry. Chem Rev 2011; 110:6104-43. [PMID: 20731375 DOI: 10.1021/cr100084g] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Giuseppe Bartoli
- Department of Organic Chemistry A. Mangini, University of Bologna, viale Risorgimento 4, I-40156 Bologna, Italy
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16
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Vermeulen NA, Delcamp JH, White MC. Synthesis of complex allylic esters via C-H oxidation vs C-C bond formation. J Am Chem Soc 2010; 132:11323-8. [PMID: 20662536 PMCID: PMC3047454 DOI: 10.1021/ja104826g] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A highly general, predictably selective C-H oxidation method for the direct, catalytic synthesis of complex allylic esters is introduced. This Pd(II)/sulfoxide-catalyzed method allows a wide range of complex aryl and alkyl carboxylic acids to couple directly with terminal olefins to furnish (E)-allylic esters in synthetically useful yields and selectivities (16 examples, E/Z >or= 10:1) and without the use of stoichiometric coupling reagents or unstable intermediates. Strategic advantages of constructing allylic esters via C-H oxidation vs C-C bond-forming methods are evaluated and discussed in four "case studies".
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Affiliation(s)
- Nicolaas A. Vermeulen
- Roger Adams Laboratory, Department of Chemistry, University of Illinois, Urbana, Illinois 61801
| | - Jared H. Delcamp
- Roger Adams Laboratory, Department of Chemistry, University of Illinois, Urbana, Illinois 61801
| | - M. Christina White
- Roger Adams Laboratory, Department of Chemistry, University of Illinois, Urbana, Illinois 61801
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17
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Furey A, O'Doherty S, O'Callaghan K, Lehane M, James KJ. Azaspiracid poisoning (AZP) toxins in shellfish: Toxicological and health considerations. Toxicon 2010; 56:173-90. [DOI: 10.1016/j.toxicon.2009.09.009] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2008] [Accepted: 09/18/2009] [Indexed: 11/29/2022]
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18
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Fandrick DR, Fandrick KR, Reeves JT, Tan Z, Tang W, Capacci AG, Rodriguez S, Song JJ, Lee H, Yee NK, Senanayake CH. Copper Catalyzed Asymmetric Propargylation of Aldehydes. J Am Chem Soc 2010; 132:7600-1. [DOI: 10.1021/ja103312x] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Daniel R. Fandrick
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury Road/P.O. Box 368, Ridgefield, Connecticut 06877-0368
| | - Keith R. Fandrick
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury Road/P.O. Box 368, Ridgefield, Connecticut 06877-0368
| | - Jonathan T. Reeves
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury Road/P.O. Box 368, Ridgefield, Connecticut 06877-0368
| | - Zhulin Tan
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury Road/P.O. Box 368, Ridgefield, Connecticut 06877-0368
| | - Wenjun Tang
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury Road/P.O. Box 368, Ridgefield, Connecticut 06877-0368
| | - Andrew G. Capacci
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury Road/P.O. Box 368, Ridgefield, Connecticut 06877-0368
| | - Sonia Rodriguez
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury Road/P.O. Box 368, Ridgefield, Connecticut 06877-0368
| | - Jinhua J. Song
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury Road/P.O. Box 368, Ridgefield, Connecticut 06877-0368
| | - Heewon Lee
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury Road/P.O. Box 368, Ridgefield, Connecticut 06877-0368
| | - Nathan K. Yee
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury Road/P.O. Box 368, Ridgefield, Connecticut 06877-0368
| | - Chris H. Senanayake
- Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury Road/P.O. Box 368, Ridgefield, Connecticut 06877-0368
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19
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Gemma S, Gabellieri E, Sanna Coccone S, Martí F, Taglialatela-Scafati O, Novellino E, Campiani G, Butini S. Synthesis of Dihydroplakortin, 6-epi-Dihydroplakortin, and Their C10-Desethyl Analogues. J Org Chem 2010; 75:2333-40. [DOI: 10.1021/jo1001559] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sandra Gemma
- Dipartimento Farmaco Chimico Tecnologico (DFCT)
- European Research Centre for Drug Discovery and Development (NatSynDrugs)
| | - Emanuele Gabellieri
- Dipartimento Farmaco Chimico Tecnologico (DFCT)
- European Research Centre for Drug Discovery and Development (NatSynDrugs)
| | - Salvatore Sanna Coccone
- Dipartimento Farmaco Chimico Tecnologico (DFCT)
- European Research Centre for Drug Discovery and Development (NatSynDrugs)
| | - Francesc Martí
- Dipartimento Farmaco Chimico Tecnologico (DFCT)
- European Research Centre for Drug Discovery and Development (NatSynDrugs)
| | - Orazio Taglialatela-Scafati
- European Research Centre for Drug Discovery and Development (NatSynDrugs)
- Dipartimento di Chimica delle Sostanze Naturali (DCSN)
| | - Ettore Novellino
- European Research Centre for Drug Discovery and Development (NatSynDrugs)
- Dipartimento di Chimica Farmaceutica e Tossicologica (DCFT)
| | - Giuseppe Campiani
- Dipartimento Farmaco Chimico Tecnologico (DFCT)
- European Research Centre for Drug Discovery and Development (NatSynDrugs)
| | - Stefania Butini
- Dipartimento Farmaco Chimico Tecnologico (DFCT)
- European Research Centre for Drug Discovery and Development (NatSynDrugs)
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20
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Evans DA, Kvaernø L, Dunn TB, Beauchemin A, Raymer B, Mulder JA, Olhava EJ, Juhl M, Kagechika K, Favor DA. Total synthesis of (+)-azaspiracid-1. An exhibition of the intricacies of complex molecule synthesis. J Am Chem Soc 2008; 130:16295-309. [PMID: 19006391 PMCID: PMC3408805 DOI: 10.1021/ja804659n] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis of the marine neurotoxin azaspiracid-1 has been accomplished. The individual fragments were synthesized by catalytic enantioselective processes: A hetero-Diels-Alder reaction to afford the E- and HI-ring fragments, a carbonyl-ene reaction to furnish the CD-ring fragment, and a Mukaiyama aldol reaction to deliver the FG-ring fragment. The subsequent fragment couplings were accomplished by aldol and sulfone anion methodologies. All ketalization events to form the nonacyclic target were accomplished under equilibrating conditions utilizing the imbedded configurations of the molecule to adopt one favored conformation. A final fragment coupling of the anomeric EFGHI-sulfone anion to the ABCD-aldehyde completed the convergent synthesis of (+)-azaspiracid-1.
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Affiliation(s)
- David A Evans
- Department of Chemistry & Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
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21
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Li J, Li X, Mootoo DR. Synthetic and Computational Studies on the ABC Trioxadispiroketal Subunit of the Marine Biotoxin Azaspiracid-1. Nat Prod Commun 2008. [DOI: 10.1177/1934578x0800301106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The trioxadispiroketal residue in the marine biotoxin azaspiracid-1, which exists in a configuration capable of exhibiting a double anomeric effect, is believed to be the thermodynamically most stable bis-spiroketal diastereomer. In order to get insight into how structural factors affect this equilibrium, a simplified ABC trioxadispiroketal analog of azaspiracid-1 was synthesized and subjected to equilbration and computational studies. Compound 7, which represents a double anomeric effect was obtained as the major isomer, together with diastereomers 14 and 15, in a respective ratio of 62:22:16. DFT calculations for 7, 14 and 15 qualitatively matched this observation. These results suggest that while a double anomeric effect may play a major role in the stability of the trioxadispiroketal configuration in the more complex natural product, the substitution pattern of the C ring is also a contributing factor.
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Affiliation(s)
- Jialiang Li
- Department of Chemistry, Hunter College/CUNY, New York, NY 10021, USA
| | - Xiaohua Li
- Department of Chemistry, Hunter College/CUNY, New York, NY 10021, USA
| | - David R. Mootoo
- Department of Chemistry, Hunter College/CUNY, New York, NY 10021, USA
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22
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Oikawa M, Uehara T, Iwayama T, Sasaki M. Synthetic study of azaspiracid-1: synthesis of the EFGHI-ring fragment. Org Lett 2007; 8:3943-6. [PMID: 16928044 DOI: 10.1021/ol0613766] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Here, we report a synthesis of the lower half C21-C40 fragment of the shellfish toxin, azaspiracid-1. The C28-C40 fragment was synthesized by a coupling between the C28-C35 epoxide and the C36-C40 dithioacetal anion, followed by the HI-ring spiroaminal formation. An aldehyde corresponding to the C28-C40 fragment was then coupled with the C21-C27 allylic stannane by using InCl3. Finally, the FG-ring was constructed by HF.pyridine to accomplish the synthesis of the suitably protected C21-C40 fragment.
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Affiliation(s)
- Masato Oikawa
- Laboratory of Biostructural Chemistry, Graduate School of Life Sciences, Tohoku University, Tsutsumidori-amamiya, Aoba-ku, Sendai 981-8555, Japan.
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Yadav J, Joyasawal S, Dutta S, Kunwar A. Stereoselective synthesis of the ABCD ring framework of azaspiracids. Tetrahedron Lett 2007. [DOI: 10.1016/j.tetlet.2007.05.021] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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24
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Nicolaou KC, Frederick MO, Petrovic G, Cole KP, Loizidou EZ. Total synthesis and confirmation of the revised structures of azaspiracid-2 and azaspiracid-3. Angew Chem Int Ed Engl 2007; 45:2609-15. [PMID: 16548033 DOI: 10.1002/anie.200600295] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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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Evans D, Kværnø L, Mulder J, Raymer B, Dunn T, Beauchemin A, Olhava E, Juhl M, Kagechika K. Total Synthesis of (+)-Azaspiracid-1. Part I: Synthesis of the Fully Elaborated ABCD Aldehyde. Angew Chem Int Ed Engl 2007. [DOI: 10.1002/ange.200701515] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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26
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Evans DA, Kvaernø L, Mulder JA, Raymer B, Dunn TB, Beauchemin A, Olhava EJ, Juhl M, Kagechika K. Total Synthesis of (+)-Azaspiracid-1. Part I: Synthesis of the Fully Elaborated ABCD Aldehyde. Angew Chem Int Ed Engl 2007; 46:4693-7. [PMID: 17546577 DOI: 10.1002/anie.200701515] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- David A Evans
- Department of Chemistry & Chemical Biology, Harvard University, Cambridge, MA 02138, USA.
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27
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Nicolaou KC, Snyder SA. Chasing molecules that were never there: misassigned natural products and the role of chemical synthesis in modern structure elucidation. Angew Chem Int Ed Engl 2007; 44:1012-1044. [PMID: 15688428 DOI: 10.1002/anie.200460864] [Citation(s) in RCA: 472] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Over the course of the past half century, the structural elucidation of unknown natural products has undergone a tremendous revolution. Before World War II, a chemist would have relied almost exclusively on the art of chemical synthesis, primarily in the form of degradation and derivatization reactions, to develop and test structural hypotheses in a process that often took years to complete when grams of material were available. Today, a battery of advanced spectroscopic methods, such as multidimensional NMR spectroscopy and high-resolution mass spectrometry, not to mention X-ray crystallography, exist for the expeditious assignment of structures to highly complex molecules isolated from nature in milligram or sub-milligram quantities. In fact, it could be argued that the characterization of natural products has become a routine task, one which no longer even requires a reaction flask! This Review makes the case that imaginative detective work and chemical synthesis still have important roles to play in the process of solving nature's most intriguing molecular puzzles.
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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, Fax: (+1) 858-784-2469
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Scott A Snyder
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA, Fax: (+1) 858-784-2469
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
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Zhou XT, Lu L, Furkert DP, Wells CE, Carter RG. Synthesis of the southern FGHI ring system of azaspiracid-1 and investigation into the controlling elements of C28- and C36-ketalization. Angew Chem Int Ed Engl 2006; 45:7622-6. [PMID: 17044107 PMCID: PMC2414259 DOI: 10.1002/anie.200603353] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Xiao-Ti Zhou
- Department of Chemistry Oregon State University Corvallis, OR 97331 USA Fax: (+ 1) 541−737−9496 E-mail:
| | - Liang Lu
- Department of Chemistry Oregon State University Corvallis, OR 97331 USA Fax: (+ 1) 541−737−9496 E-mail:
| | - Daniel P. Furkert
- Department of Chemistry Oregon State University Corvallis, OR 97331 USA Fax: (+ 1) 541−737−9496 E-mail:
| | - Charles E. Wells
- Department of Chemistry Oregon State University Corvallis, OR 97331 USA Fax: (+ 1) 541−737−9496 E-mail:
| | - Rich G. Carter
- Department of Chemistry Oregon State University Corvallis, OR 97331 USA Fax: (+ 1) 541−737−9496 E-mail:
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Zhou XT, Lu L, Furkert DP, Wells CE, Carter RG. Synthesis of the Southern FGHI Ring System of Azaspiracid-1 and Investigation into the Controlling Elements of C28- and C36-Ketalization. Angew Chem Int Ed Engl 2006. [DOI: 10.1002/ange.200603353] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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30
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Nicolaou KC, Frederick MO, Loizidou EZ, Petrovic G, Cole KP, Koftis TV, Yamada YMA. Second-Generation Total Synthesis of Azaspiracids-1, -2, and -3. Chem Asian J 2006; 1:245-63. [PMID: 17441061 DOI: 10.1002/asia.200600059] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The naturally occurring but scarce marine neurotoxins azaspiracids-1, -2, and -3 have been synthesized from five key building blocks by a convergent strategy that involved dithiane and Stille coupling reactions. The ABCD fragments were constructed through a cascade reaction involving deprotection/self-assembly of the precursors, while the FGHI fragment was forged by a neodymium triflate-induced cyclization. The final ring closure (ring G) was achieved, after the union of all fragments, through an iodoetherification reaction followed by reductive removal of the facilitating iodine residue. These improved, second-generation routes confirm the absolute structures and render all three azaspiracids readily available for biological studies.
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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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31
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Nicolaou KC, Frederick MO, Petrovic G, Cole KP, Loizidou EZ. Total Synthesis and Confirmation of the Revised Structures of Azaspiracid-2 and Azaspiracid-3. Angew Chem Int Ed Engl 2006. [DOI: 10.1002/ange.200600295] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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32
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Zhou XT, Carter RG. Synthesis of the C1–C26 Northern Portion of Azaspiracid-1: Kinetic versus Thermodynamic Control of the Formation of the Bis-spiroketal. Angew Chem Int Ed Engl 2006. [DOI: 10.1002/ange.200503733] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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33
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Zhou XT, Carter RG. Synthesis of the C1-C26 northern portion of azaspiracid-1: kinetic versus thermodynamic control of the formation of the bis-spiroketal. Angew Chem Int Ed Engl 2006; 45:1787-90. [PMID: 16470899 PMCID: PMC2414258 DOI: 10.1002/anie.200503733] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Xiao-Ti Zhou
- Department of Chemistry, Oregon State University, Corvallis, 97331, USA
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34
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Nicolaou KC, Pihko PM, Bernal F, Frederick MO, Qian W, Uesaka N, Diedrichs N, Hinrichs J, Koftis TV, Loizidou E, Petrovic G, Rodriquez M, Sarlah D, Zou N. Total Synthesis and Structural Elucidation of Azaspiracid-1. Construction of Key Building Blocks for Originally Proposed Structure. J Am Chem Soc 2006; 128:2244-57. [PMID: 16478178 DOI: 10.1021/ja0547477] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Syntheses of the three key building blocks (65, 98, and 100) required for the total synthesis of the proposed structure of azaspiracid-1 (1a) are described. Key steps include a TMSOTf-induced ring-closing cascade to form the ABC rings of tetracycle 65, a neodymium-catalyzed internal aminal formation for the construction of intermediate 98, and a Nozaki-Hiyama-Kishi coupling to assemble the required carbon chain of fragment 100. The synthesized fragments, obtained stereoselectively in both their enantiomeric forms, were expected to allow for the construction of all four stereoisomers proposed as possible structures of azaspiracid-1 (1a-d), thus allowing the determination of both the relative and absolute stereochemistry of the natural product.
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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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Abstract
[reaction: see text] The synthesis of the C9-C26 portion of amphidinolide B1 is described. A Fleming allylation followed by elimination was employed for the construction of the C13-C15 diene portion. Sharpless asymmetric dihydroxylation was utilized for regioselective functionalization of a styrene-derived alkene, in the presence of the C13-C15 diene functionality. A highly diastereoselective aldol reaction was developed to establish the C18 stereochemistry.
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Affiliation(s)
- Wei Zhang
- Department of Chemistry, 153 Gilbert Hall, Oregon State University, Corvallis, Oregon 97331, USA
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Kojima S, Hidaka T, Yamakawa A. Application of Organocerium Reagents for the Efficient Conversion ofZ-α,β-Unsaturated Weinreb Amides toZ-α,β-Unsaturated Ketones. CHEM LETT 2005. [DOI: 10.1246/cl.2005.470] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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37
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Nicolaou KC, Snyder SA. Die Jagd auf Moleküle, die nie existiert haben: Falsch zugeordnete Naturstoffstrukturen und die Rolle der chemischen Synthese in der modernen Strukturaufklärung. Angew Chem Int Ed Engl 2005. [DOI: 10.1002/ange.200460864] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- K. C. Nicolaou
- Department of Chemistry und The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA, Fax: (+1) 858‐784‐2469
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Scott A. Snyder
- Department of Chemistry und The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA, Fax: (+1) 858‐784‐2469
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
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Abstract
The efficient syntheses of the ABCD ring system of the originally proposed structure of azaspiracid-1 and the ABCDE ring system of the revised structure of azaspiracid-1 containing the correct stereochemistry at C(6), C(10), C(13), C(14), C(16), C(17), C(19), C(21), C(22), C(24) and C(25) have been achieved.
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James KJ, Fidalgo Sáez MJ, Furey A, Lehane M. Azaspiracid poisoning, the food-borne illness associated with shellfish consumption. ACTA ACUST UNITED AC 2004; 21:879-92. [PMID: 15666982 DOI: 10.1080/02652030400002105] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Azaspiracid poisoning (AZP) is a recently discovered toxic syndrome that was identified following severe gastrointestinal illness from the consumption of contaminated mussels (Mytilus edulis). The implicated toxins, azaspiracids, are polyethers with unprecedented structural features. Studies toward total toxin synthesis revealed that the initial published structures were incorrect and they have now been revised. These toxins accumulate in bivalve molluscs that feed on toxic microalgae of the genus Protoperidinium, previously considered to be toxicologically benign. Although first identified in shellfish from Ireland, azaspiracid contamination of several types of bivalve shellfish species has now been confirmed throughout the western coastline of Europe. Toxicological studies have indicated that azaspiracids can induce widespread organ damage in mice and that they are probably more dangerous than previously known classes of shellfish toxins. The exclusive reliance on live animal bioassays to monitor azaspiracids in shellfish failed to prevent human intoxications. This was a consequence of poor sensitivity of the assay and the fact that azaspiracids are not exclusively found in the shellfish digestive glands used for toxin testing. The strict regulatory control of azaspiracids in shellfish now requires frequent testing of shellfish using highly specific and sensitive methods involving liquid chromatography-mass spectrometry.
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Affiliation(s)
- K J James
- Proteobio, Mass Spectrometry Centre for Proteomics and Biotoxin Research, Department of Chemistry, Cork Institute of Technology, Bishopstown, Cork, Ireland.
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Nishiyama S, Ishikawa Y. Synthesis of the ABCD Ring System of Azaspiracid, a Marine Poison from Mytilus edulis. HETEROCYCLES 2004. [DOI: 10.3987/com-03-10000] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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42
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Synthesis of the BCD ring system of azaspiracid: construction of the trispiro ring structure by the thioether approach. Tetrahedron Lett 2004. [DOI: 10.1016/j.tetlet.2003.10.161] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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43
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Mas G, González L, Vilarrasa J. Synthetic routes to the stereoisomers of 2,4-dimethylpentane-1,5-diol derivatives. Tetrahedron Lett 2003. [DOI: 10.1016/j.tetlet.2003.09.199] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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44
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Carter RG, Bourland T, Zhou XT, Gronemeyer MA. Controlling influences in bisspiroketal formation: synthesis of the ABC ring system of azaspiracid. Tetrahedron 2003. [DOI: 10.1016/j.tet.2003.03.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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45
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Carter RG, Graves DE, Gronemeyer MA, Tschumper GS. Synthesis of the ABC ring system of Azaspiracid. 2. A systematic study into the effect of C(16) and C(17) substitution on bis-spirocyclization. Org Lett 2002; 4:2181-4. [PMID: 12074662 PMCID: PMC2424254 DOI: 10.1021/ol026034o] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[reaction: see text] A systematic study into the effect of C(16) and C(17) substitution on the stereochemical outcome of bis-spirocyclization to form the ABC ring system of azaspiracid is disclosed. Successful construction of the natural 10R,13R bis-spirocyclic stereochemistry has been accomplished on the C(16) benzyloxy-containing precursor.
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Affiliation(s)
- Rich G Carter
- Department of Chemistry and Biochemistry, University of Mississippi, University, Mississippi 38677, USA.
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Carter RG, Bourland TC, Graves DE. Synthesis of the ABC ring system of azaspiracid. 1. Effect of D ring truncation on bis-spirocyclization. Org Lett 2002; 4:2177-9. [PMID: 12074661 PMCID: PMC2424237 DOI: 10.1021/ol026033w] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[reaction: see text] Synthesis of a spirocyclization precursor with a truncated D ring has been accomplished. Subsequent bis-spirocyclization induced the formation of equal amounts of the natural transoidal 10R,13R bis-spirocycle and its cisoidal 10R,13S epimer under an apparent thermodynamically controlled process.
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Affiliation(s)
- Rich G Carter
- Department of Chemistry and Biochemistry, University of Mississippi, University, Mississippi 38677, USA.
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Forsyth CJ, Hao J, Aiguade J. Synthesis of the (+)‐C26–C40 Domain of the Azaspiracids by a Novel Double Intramolecular Hetero‐Michael Addition Strategy. Angew Chem Int Ed Engl 2001. [DOI: 10.1002/1521-3757(20011001)113:19<3775::aid-ange3775>3.0.co;2-#] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Craig J. Forsyth
- Department of Chemistry Institute of Technology University of Minnesota Minneapolis, MN 55455, USA, Fax: (+1) 612‐626‐7541
| | - Junliang Hao
- Department of Chemistry Institute of Technology University of Minnesota Minneapolis, MN 55455, USA, Fax: (+1) 612‐626‐7541
| | - Josep Aiguade
- Department of Chemistry Institute of Technology University of Minnesota Minneapolis, MN 55455, USA, Fax: (+1) 612‐626‐7541
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50
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Carter RG, Graves DE. Studies directed toward the total synthesis of azaspiracid. Construction of the C1–C19 carbon backbone and synthesis of the C10, C13 nonnatural transoidal bisspirocyclic ring system. Tetrahedron Lett 2001. [DOI: 10.1016/s0040-4039(01)01211-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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