1
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Chintalapudi V, Wilson C, Clark JS. Synthesis of the I-K Fused Polyether Array of CTX3C and Related Ciguatoxins by Use of a Gold-Catalyzed Cyclization Reaction. Org Lett 2024; 26:775-780. [PMID: 38238251 PMCID: PMC10845158 DOI: 10.1021/acs.orglett.3c03782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 01/04/2024] [Accepted: 01/15/2024] [Indexed: 02/03/2024]
Abstract
The I-K fragment (C31-C49) of the ciguatoxin CTX3C has been synthesized from a simple chiral pool derived tetrahydropyranyl alcohol. An efficient gold-catalyzed cyclization reaction of a γ'-hydroxy ynone has been used to accomplish efficient closure of ring K under mild conditions. The resulting vinylogous ester has been elaborated to give a complete tricyclic fragment bearing the dimethyl-substituted side chain required for assembly of the LM spirocyclic acetal portion of the target.
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Affiliation(s)
| | - Claire Wilson
- School of Chemistry, Joseph
Black Building, University of Glasgow, University Avenue, Glasgow, G12 8QQ, U.K.
| | - J. Stephen Clark
- School of Chemistry, Joseph
Black Building, University of Glasgow, University Avenue, Glasgow, G12 8QQ, U.K.
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2
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Hussain N, Rasool F, Khan S, Saleem M, Maheshwari M. Advances in the Synthesis of Natural Products and Medicinally Relevant Molecules from Glycals. ChemistrySelect 2022. [DOI: 10.1002/slct.202201873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Nazar Hussain
- Department of Medicinal Chemistry Banaras Hindu University India
| | - Faheem Rasool
- Department of Chemistry Govt. College for Women, Parade Ground Jammu 180001 India
| | - Shahnawaz Khan
- Department of Chemistry Central University of Jammu 180001 Jammu India
| | - Mohd Saleem
- Department of Chemistry Govt.Postgraduate college Rajouri India
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3
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Padhi B, Reddy GS, Mallampudi NA, Choudhury UM, Mohapatra DK. CuBr 2-catalyzed diastereoselective allylation: total synthesis of decytospolides A and B and their C6-epimers. Org Biomol Chem 2020; 18:2685-2695. [PMID: 32202577 DOI: 10.1039/c9ob02689d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An efficient CuBr2-catalyzed diastereoselective allylation of a cyclic hemiacetal with allyltrimethylsilane as a nucleophile has been developed. The protocol offers a cost effective, protecting group tolerant, and operationally simple approach to 2,6-trans-disubstituted tetrahydropyran with excellent diastereoselectivity. Furthermore, the application of this methodology has been demonstrated in the total synthesis of decytospolides A and B and their C6-epimers.
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Affiliation(s)
- Birakishore Padhi
- Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad-500007, India.
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4
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Ota Y, Kondoh A, Terada M. Enantioselective Intramolecular Nicholas Reaction Catalyzed by Chiral Phosphoric Acid: Enantioconvergent Synthesis of Seven-Membered Cyclic Ethers from Racemic Diols. Angew Chem Int Ed Engl 2018; 57:13917-13921. [PMID: 30160819 DOI: 10.1002/anie.201808239] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Revised: 08/11/2018] [Indexed: 11/09/2022]
Abstract
An enantioconvergent intramolecular Nicholas reaction of racemic diols was developed using BINOL- and SPINOL-derived phosphoric acids as the chiral Brønsted acid catalyst. The developed reaction features an efficient approach to the synthesis of seven-membered cyclic ethers in a highly enantioselective manner. Further derivatization of the enantioenriched cyclic ethers, initiated by the de-complexation of the dicobalt species, afforded densely functionalized cyclic ethers having an unsaturated diester moiety without loss of enantiomeric excess.
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Affiliation(s)
- Yusuke Ota
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai, 980-8578, Japan
| | - Azusa Kondoh
- Research and Analytical Center for Giant Molecules, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai, 980-8578, Japan
| | - Masahiro Terada
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai, 980-8578, Japan
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5
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Ota Y, Kondoh A, Terada M. Enantioselective Intramolecular Nicholas Reaction Catalyzed by Chiral Phosphoric Acid: Enantioconvergent Synthesis of Seven‐Membered Cyclic Ethers from Racemic Diols. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201808239] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Yusuke Ota
- Department of ChemistryGraduate School of ScienceTohoku University Aramaki Aoba-ku Sendai 980-8578 Japan
| | - Azusa Kondoh
- Research and Analytical Center for Giant MoleculesGraduate School of ScienceTohoku University Aramaki Aoba-ku Sendai 980-8578 Japan
| | - Masahiro Terada
- Department of ChemistryGraduate School of ScienceTohoku University Aramaki Aoba-ku Sendai 980-8578 Japan
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6
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Roscales S, Ortega V, Csákÿ AG. Selective Functionalization of Achmatowicz Rearrangement Products by Reactions with Potassium Organotrifluoroborates under Transition-Metal-Free Conditions. J Org Chem 2018; 83:11425-11436. [PMID: 30036474 DOI: 10.1021/acs.joc.8b01643] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The repertoire of synthetic transformations of the products of the Achmatowicz rearrangement has been expanded by exploring their reactivity with potassium organotrifluoroborates in the absence of transition metals. Depending on the reaction conditions and the substitution pattern of the starting material, the reaction may lead to the stereoselective synthesis of dihydropyranones (2,6- trans), tetrahydropyranones (2,3- cis-2,6- cis) or functionalized 1,4-dicarbonyl compounds. The method has also been adapted for the one-pot synthesis of functionalized pyrroles.
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Affiliation(s)
- Silvia Roscales
- Instituto Pluridisciplinar, Universidad Complutense, Campus de Excelencia Internacional Moncloa , Paseo de Juan XXIII, 1 , 28040 Madrid , Spain
| | - Víctor Ortega
- Instituto Pluridisciplinar, Universidad Complutense, Campus de Excelencia Internacional Moncloa , Paseo de Juan XXIII, 1 , 28040 Madrid , Spain
| | - Aurelio G Csákÿ
- Instituto Pluridisciplinar, Universidad Complutense, Campus de Excelencia Internacional Moncloa , Paseo de Juan XXIII, 1 , 28040 Madrid , Spain
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7
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Morozova V, Moriya K, Mayer P, Knochel P. Stereoselective Synthesis and Retentive Trapping of α-Chiral Secondary Alkyllithiums Leading to Stereodefined α,β-Dimethyl Carboxylic Esters. Chemistry 2016; 22:9962-5. [DOI: 10.1002/chem.201601911] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2016] [Indexed: 12/25/2022]
Affiliation(s)
- Varvara Morozova
- Department Chemie; Ludwig-Maximilians-Universität München; Butenandtstrasse 5-13 81377 München Germany
| | - Kohei Moriya
- Department Chemie; Ludwig-Maximilians-Universität München; Butenandtstrasse 5-13 81377 München Germany
| | - Peter Mayer
- Department Chemie; Ludwig-Maximilians-Universität München; Butenandtstrasse 5-13 81377 München Germany
| | - Paul Knochel
- Department Chemie; Ludwig-Maximilians-Universität München; Butenandtstrasse 5-13 81377 München Germany
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8
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Kolodziej I, Green JR. Vinylogous Nicholas reactions in the synthesis of bi- and tricyclic cycloheptynedicobalt complexes. Org Biomol Chem 2015; 13:10852-64. [DOI: 10.1039/c5ob01684c] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The Lewis acid mediated intramolecular Nicholas reactions of allylic acetate enyne-Co2(CO)6 complexes afford bicyclic- and tricyclic cycloheptenyne-Co2(CO)6 complexes.
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Affiliation(s)
- Izabela Kolodziej
- Department of Chemistry and Biochemistry
- University of Windsor
- Windsor
- Canada
| | - James R. Green
- Department of Chemistry and Biochemistry
- University of Windsor
- Windsor
- Canada
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9
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Diastereoselective cobalt-assisted Ferrier-type rearrangement to construct chiral alkynyl cyclohexanones. Tetrahedron 2014. [DOI: 10.1016/j.tet.2014.09.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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10
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Yoshida S, Hatakeyama Y, Johmoto K, Uekusa H, Hosoya T. Transient Protection of Strained Alkynes from Click Reaction via Complexation with Copper. J Am Chem Soc 2014; 136:13590-3. [DOI: 10.1021/ja507660x] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Suguru Yoshida
- Laboratory
of Chemical Bioscience, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan
| | - Yasutomo Hatakeyama
- Laboratory
of Chemical Bioscience, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan
| | - Kohei Johmoto
- Department
of Chemistry and Materials Science, Graduate School of Science and
Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan
| | - Hidehiro Uekusa
- Department
of Chemistry and Materials Science, Graduate School of Science and
Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan
| | - Takamitsu Hosoya
- Laboratory
of Chemical Bioscience, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-0062, Japan
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11
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Wu YB, Tang Y, Luo GY, Chen Y, Hsung RP. An Approach toward Constructing the Trioxadispiroketal Core in the DEF-Ring of (+)-Spirastrellolide A. Org Lett 2014; 16:4550-3. [DOI: 10.1021/ol502103b] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Yi-Biao Wu
- School of Pharmaceutical Science and Technology, Key Laboratory for Modern Drug Delivery & High-Efficiency, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin, 300072 P. R. China
| | - Yu Tang
- School of Pharmaceutical Science and Technology, Key Laboratory for Modern Drug Delivery & High-Efficiency, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin, 300072 P. R. China
| | - Guo-Ying Luo
- School of Pharmaceutical Science and Technology, Key Laboratory for Modern Drug Delivery & High-Efficiency, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin, 300072 P. R. China
| | - Yang Chen
- School of Pharmaceutical Science and Technology, Key Laboratory for Modern Drug Delivery & High-Efficiency, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin, 300072 P. R. China
| | - Richard P. Hsung
- Division of Pharmaceutical Sciences, School of Pharmacy, and Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53705 United States
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12
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Zhou T, Shi Q, Bastow KF, Lee KH. Antitumor agents 286. Design, synthesis, and structure-activity relationships of 3'R,4'R-disubstituted-2',2'-dimethyldihydropyrano[2,3-f]chromone (DSP) analogues as potent chemosensitizers to overcome multidrug resistance. J Med Chem 2010; 53:8700-8. [PMID: 21082774 DOI: 10.1021/jm101249z] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
In this study, various 3'R,4'R-disubstituted-2',2'-dimethydihydropyrano[2,3-f]chromone (DSP) derivatives were discovered as potent chemosensitizers in the treatment of multidrug resistant cancer cells. Twenty-four DSP analogues (5-28) were synthesized and evaluated against a multidrug resistant (MDR) cell line (KB-Vin) with and without vincristine (VCR). All DSP analogues exhibited low intrinsic cytotoxicity. However, in combination treatment, most DSPs reversed resistance to VCR and lowered the GI₅₀ value of VCR by 12-349-fold. At a concentration of 1 μg/mL, three compounds, 11, 14, and 21, fully reversed resistance to VCR in KB-Vin cancer cells, a 2-fold increase compared to verapamil, a first-generation chemosensitizer. Detailed structure-activity relationship (SAR) conclusions were established based on 3' and 4' substitutions. Moreover, a preliminary mechanism study indicated that the chemosensitizing activity of DSP analogues results from inhibition of P-glycoprotein (P-gp) overexpressed in MDR cancer cells.
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Affiliation(s)
- Ting Zhou
- Natural Products Research Laboratories, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599-7568, USA
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13
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Djurdjevic S, Yang F, Green JR. Intramolecular Nicholas reactions in the synthesis of dibenzocycloheptanes. Synthesis of allocolchicine NSC 51046 and analogues and the formal synthesis of (-)-allocolchicine. J Org Chem 2010; 75:8241-51. [PMID: 21058661 DOI: 10.1021/jo101953n] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The preparation of dibenzocycloheptyne-Co(2)(CO)(6) complexes by intramolecular Nicholas reactions of biaryl-2-propargyl alcohol-Co(2)(CO)(6) derivatives is described. Reductive decomplexation of the dibenzocycloheptyne-Co(2)(CO)(6) complexes affords the corresponding dibenzocycloheptenes, individual members of which have been employed in a formal total synthesis of (-)-allocolchicine, the preparation of 6,7-dihydro-3,4,9,10,11-pentamethoxy-5H-dibenzo[a,c]cyclohepten-5-one, and the enantioselective total syntheses of NSC 51046 and its 3,8,9,10-tetramethoxy regioisomer.
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Affiliation(s)
- Sinisa Djurdjevic
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada
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14
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Isobe M, Hamajima A. Ciguatoxin: developing the methodology for total synthesis. Nat Prod Rep 2010; 27:1204-26. [DOI: 10.1039/b919467n] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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15
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Abstract
Something fishy: Ciguatoxin (see structure) is one of the principal toxins involved in ciguatera poisoning and the target of a total synthesis involving the coupling of three segments. The key transformations in this synthesis feature acetylene-dicobalthexacarbonyl complexation.
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Affiliation(s)
- Akinari Hamajima
- Laboratory of Organic Chemistry, Bioagricultural Sciences, Nagoya University, Furocho, Chikusa 464-8601, Nagoya, Japan
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16
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17
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18
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Lorpitthaya R, Xie ZZ, Kuo JL, Liu XW. Stereocontrolled intramolecular aziridination of glycals: ready access to aminoglycosides and mechanistic insights from DFT studies. Chemistry 2008; 14:1561-70. [PMID: 18046690 DOI: 10.1002/chem.200701288] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Stereocontrolled intramolecular aziridination of the glycal-derived sulfamates offers a highly efficient strategy to divergently prepare aminoglycosides. Rhodium-catalyzed nitrogen-atom transfer to C==C bonds formed semistable aziridines, which were subjected to various nucleophiles (C, O, S, and N) to give cyclic sulfamate-containing aminosugar derivatives selectively. The second nucleophilic displacement of sulfonyloxy moieties of [1,2,3]-oxathiazepane-2,2- dioxides allows straightforward access to aminoglycosides with selective alpha- or beta-linkages. This approach is operationally simple, complements existing methods, and is a versatile protocol for the synthesis of polyfunctionalized amino sugars. In addition, the mechanism of the rhodium-catalyzed intramolecular aziridination of glycals and its ring-opening reaction was extensively studied by using DFT calculations.
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Affiliation(s)
- Rujee Lorpitthaya
- Division of Chemistry and Biological Chemistry, School of Physical & Mathematical Sciences, Nanyang Technological University, 1 Nanyang Walk, Singapore 637616, Singapore
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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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Djurdjevic S, Green JR. Allocolchicines via Intramolecular Nicholas Reactions: The Synthesis of NSC 51046. Org Lett 2007; 9:5505-8. [DOI: 10.1021/ol7024422] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sinisa Djurdjevic
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON, Canada N9B 3P4, and St. Clair College of Applied Arts and Technology, Windsor, ON, Canada N9A 6S4
| | - James R. Green
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON, Canada N9B 3P4, and St. Clair College of Applied Arts and Technology, Windsor, ON, Canada N9A 6S4
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21
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Abstract
The first total synthesis of the natural cytotoxic agent sporiolide A has been accomplished from D-glucal in 16 steps with 6.1% overall yield. Carbohydrates were applied as the chiral templates to manipulate the absolute configuration during the synthesis. Pyridinium chlorochromate (PCC)-promoted transformation of the cyclic enol-ether to lactone, followed by Yamaguchi esterification and intramolecular ring closure metathesis, greatly facilitates synthesis of the target compound.
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Affiliation(s)
- Yuguo Du
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
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22
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Chen Q, Du Y. Synthesis of sporiolide B from d-glucal. Carbohydr Res 2007; 342:1405-11. [PMID: 17517381 DOI: 10.1016/j.carres.2007.04.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2007] [Revised: 04/19/2007] [Accepted: 04/20/2007] [Indexed: 11/30/2022]
Abstract
A total synthesis of the 12-membered ring natural macrolide, sporiolide B, was achieved from D-glucal in 17 steps with 4.8% overall yield. The required stereochemical configuration at C-3 and C-5 in sporiolide B was easily introduced by applying a Mitsunobu reaction on the chiral template D-glucal. Yamaguchi esterification and ring closing metathesis greatly improved the access to the target compound.
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Affiliation(s)
- Qi Chen
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China
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24
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Takizawa A, Fujiwara K, Doi E, Murai A, Kawai H, Suzuki T. Convergent synthesis of the common FGHI-ring part of ciguatoxins. Tetrahedron 2006. [DOI: 10.1016/j.tet.2006.05.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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25
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Abstract
[reaction: see text] A convergent synthesis of the right-hand half of ciguatoxin (the HIJKLM ring system) has been achieved with complete stereocontrol in the introduction of the stereocenters on the eight-membered I ring. Key steps are Sonogashira coupling, dicobalt complexation, intramolecular conjugate addition, and hydrogenation of an endo-olefin to provide the 39-alpha-methyl group.
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Affiliation(s)
- Akinari Hamajima
- Laboratory of Organic Chemistry, School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan
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26
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27
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Aho JE, Pihko PM, Rissa TK. Nonanomeric Spiroketals in Natural Products: Structures, Sources, and Synthetic Strategies. Chem Rev 2005; 105:4406-40. [PMID: 16351049 DOI: 10.1021/cr050559n] [Citation(s) in RCA: 325] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jatta E Aho
- Laboratory of Organic Chemistry, Helsinki University of Technology, TKK, Finland
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28
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29
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Domon D, Fujiwara K, Murai A, Kawai H, Suzuki T. Convergent synthesis of the IJKLM-ring part of ciguatoxin CTX3C. Tetrahedron Lett 2005. [DOI: 10.1016/j.tetlet.2005.09.164] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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30
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Synthesis of the EF-ring segment of ciguatoxin CTX1B based on novel regioselective reduction of unsaturated cyanohydrins and ring-closing olefin metathesis. Tetrahedron 2005. [DOI: 10.1016/j.tet.2005.05.073] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Abstract
More than 20 000 people suffer annually from ciguatera seafood poisoning in subtropical and tropical regions. The extremely low content of the causative neurotoxins, designated as ciguatoxins, in fish has hampered their isolation, detailed biological study, and preparation of anti-ciguatoxin antibodies for detecting these toxins. Ciguatoxins consist of 12 trans-fused polycyclic ethers, ranging from six- to nine-membered, and include a spirally attached five-membered cyclic ether at one end. The large (3 nm in length) and complicated molecular structure of ciguatoxins has impeded chemists from completing their total synthesis. In 2001, we achieved the first total synthesis of ciguatoxin CTX3C by assembly of four structural fragments. Since then, protocols to combine the fragments have significantly improved in terms of overall stereoselectivity, efficiency, and practicality. In this Account, we describe recently evolved methodologies for the total synthesis of CTX3C.
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Affiliation(s)
- Masayuki Inoue
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.
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32
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34
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A new synthesis of key intermediates for the assembly of polycyclic ethers: Yb(OTf)3-promoted formation of O,S-acetals from α-fluorosulfides and alcohols. Tetrahedron Lett 2004. [DOI: 10.1016/j.tetlet.2004.01.077] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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35
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Mohamed AB, Green JR. Tethered 2 + 2 + 2 cycloaddition reactions of cobalt–cycloheptyne complexes. Chem Commun (Camb) 2003:2936-7. [PMID: 14680249 DOI: 10.1039/b310511c] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cycloheptyne-dicobalt hexacarbonyl complexes, substituted by propargylic ether functions, undergo 2 + 2 + 2 cycloaddition reactions with alkynes to give tricyclic benzocycloheptanes; an all-intramolecular version of this transformation is also possible.
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Affiliation(s)
- Ahmed B Mohamed
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON N9B 3P4, Canada
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