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Thesmar P, Coomar S, Prescimone A, Häussinger D, Gillingham D, Baudoin O. Divergent Synthesis of Bioactive Dithiodiketopiperazine Natural Products Based on a Double C(sp 3 )-H Activation Strategy. Chemistry 2020; 26:15298-15312. [PMID: 32852800 DOI: 10.1002/chem.202003683] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 08/26/2020] [Indexed: 12/28/2022]
Abstract
This article provides a detailed report of our efforts to synthesize the dithiodiketopiperazine (DTP) natural products (-)-epicoccin G and (-)-rostratin A using a double C(sp3 )-H activation strategy. The strategy's viability was first established on a model system lacking the C8/C8' alcohols. Then, an efficient stereoselective route including an organocatalytic epoxidation was secured to access a key bis-triflate substrate. This bis-triflate served as the functional handles for the key transformation of the synthesis: a double C(sp3 )-H activation. The successful double activation opened access to a common intermediate for both natural products in high overall yield and on a multigram scale. After several unsuccessful attempts, this intermediate was efficiently converted to (-)-epicoccin G and to the more challenging (-)-rostratin A via suitable oxidation/reduction and protecting group sequences, and via a final sulfuration that occurred in good yield and high diastereoselectivity. These efforts culminated in the synthesis of (-)-epicoccin G and (-)-rostratin A in high overall yields (19.6 % over 14 steps and 12.7 % over 17 steps, respectively), with the latter being obtained on a 500 mg scale. Toxicity assessments of these natural products and several analogues (including the newly synthesized epicoccin K) in the leukemia cell line K562 confirmed the importance of the disulfide bridge for activity and identified dianhydrorostratin A as a 20x more potent analogue.
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Affiliation(s)
- Pierre Thesmar
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
| | - Seemon Coomar
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
| | - Alessandro Prescimone
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
| | - Daniel Häussinger
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
| | - Dennis Gillingham
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
| | - Olivier Baudoin
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056, Basel, Switzerland
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Thesmar P, Baudoin O. Efficient and Divergent Total Synthesis of (-)-Epicoccin G and (-)-Rostratin A Enabled by Double C(sp 3)-H Activation. J Am Chem Soc 2019; 141:15779-15783. [PMID: 31556609 DOI: 10.1021/jacs.9b09359] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Dithiodiketopiperazines are complex polycyclic natural products possessing a variety of interesting biological activities. Despite their interest, relatively few total syntheses have been completed. We herein report the enantioselective, scalable, and divergent total synthesis of two symmetrical pentacyclic dithiodiketopiperazines, (-)-epicoccin G and (-)-rostratin A. A common intermediate was synthesized on a multigram scale from inexpensive, commercially available starting materials using an enantioselective organocatalytic epoxidation and a double C(sp3)-H activation as key steps, with the latter allowing the efficient simultaneous construction of the two five-membered rings. In addition to the cis,cis-fused target (-)-epiccocin G, the more challenging (-)-rostratin A, possessing two trans ring junctions, was obtained for the first time on a 500 mg scale through the optimization of each step and validation on multigram quantities. Both natural products were synthesized with high overall yields (13-20%). This study should facilitate access to this fascinating and yet understudied family of biologically active natural products.
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Affiliation(s)
- Pierre Thesmar
- Department of Chemistry , University of Basel , St. Johanns-Ring 19 , CH-4056 Basel , Switzerland
| | - Olivier Baudoin
- Department of Chemistry , University of Basel , St. Johanns-Ring 19 , CH-4056 Basel , Switzerland
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Liu Y, Wang ZP, Banne S, Guo J, He Y. Toward the Total Synthesis of Scabrosins: Synthesis of a Desulfur-scabrosin Skeleton and Its Stereoisomers. J Org Chem 2019; 84:5838-5845. [PMID: 30900891 DOI: 10.1021/acs.joc.9b00015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The enantioselective synthesis of a desulfur-scabrosin skeleton was reported. The synthesis began from 3-(hydroxymethyl)phenol, and key steps include asymmetric nucleophilic epoxidation, a Mitsunobu reaction using a sulfonamide as the nucleophile, the construction of a pyrrolidine ring by intramolecular nucleophilic substitution, and inversion of configuration through base-induced keto-enol isomerization. Additionally, two isomers of the carbon skeleton were also obtained via an alternative ring-closing strategy.
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Affiliation(s)
- Yuyin Liu
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences , Chongqing University , Chongqing 401331 , People's Republic of China
| | - Zhi-Peng Wang
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences , Chongqing University , Chongqing 401331 , People's Republic of China
| | - Sreenivas Banne
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences , Chongqing University , Chongqing 401331 , People's Republic of China
| | - Jian Guo
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences , Chongqing University , Chongqing 401331 , People's Republic of China
| | - Yun He
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences , Chongqing University , Chongqing 401331 , People's Republic of China
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Angello NH, Wiley RE, Elmore TG, Perry RS, Scheerer JR. Domino Reaction Sequence for the Synthesis of [2.2.2]Diazabicycloalkenes and Base-Promoted Cycloreversion to 2-Pyridone Alkaloids. Org Lett 2018; 20:5203-5207. [PMID: 30095269 PMCID: PMC6220673 DOI: 10.1021/acs.orglett.8b02145] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A new domino reaction sequence for the construction of 2-pyridone structures is reported. The reaction sequence begins with diacetyldiketopiperazine and proceeds via aldol condensation, alkene isomerization, and intramolecular Diels-Alder cycloaddition. The intermediate [2.2.2]diazabicycloalkene cycloadducts can be isolated or can engage in a base-accelerated extrusion of one lactam bridge to provide the 2-pyridone cycloreversion products. The operation leading to pyridone products can occur in one reaction vessel and proceeds at convenient temperatures.
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Affiliation(s)
- Nicholas H. Angello
- Department of Chemistry, The College of William & Mary, P.O. Box 8795, Williamsburg, Virginia 23187, United States
| | - Robert E. Wiley
- Department of Chemistry, The College of William & Mary, P.O. Box 8795, Williamsburg, Virginia 23187, United States
| | - Tristan G. Elmore
- Department of Chemistry, The College of William & Mary, P.O. Box 8795, Williamsburg, Virginia 23187, United States
| | - Ryan S. Perry
- Department of Chemistry, The College of William & Mary, P.O. Box 8795, Williamsburg, Virginia 23187, United States
| | - Jonathan R. Scheerer
- Department of Chemistry, The College of William & Mary, P.O. Box 8795, Williamsburg, Virginia 23187, United States
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Hughes JM, Gleason JL. A bio-inspired cascade and a late-stage directed sp3 C H lithiation enables a concise total synthesis of (−)-virosaine A. Tetrahedron 2018. [DOI: 10.1016/j.tet.2017.12.026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Barbero H, Díez-Poza C, Barbero A. The Oxepane Motif in Marine Drugs. Mar Drugs 2017; 15:E361. [PMID: 29140270 PMCID: PMC5706050 DOI: 10.3390/md15110361] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 11/03/2017] [Accepted: 11/08/2017] [Indexed: 12/12/2022] Open
Abstract
Oceans have shown to be a remarkable source of natural products. The biological properties of many of these compounds have helped to produce great advances in medicinal chemistry. Within them, marine natural products containing an oxepanyl ring are present in a great variety of algae, sponges, fungus and corals and show very important biological activities, many of them possessing remarkable cytotoxic properties against a wide range of cancer cell lines. Their rich chemical structures have attracted the attention of many researchers who have reported interesting synthetic approaches to these targets. This review covers the most prominent examples of these types of compounds, focusing the discussion on the isolation, structure determination, medicinal properties and total synthesis of these products.
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Affiliation(s)
- Héctor Barbero
- GIR MIOMeT, IU CINQUIMA/Inorganic Chemistry, University of Valladolid, Campus Miguel Delibes, 47011 Valladolid, Spain.
| | - Carlos Díez-Poza
- Department of Organic Chemistry, University of Valladolid, Campus Miguel Delibes, 47011 Valladolid, Spain.
| | - Asunción Barbero
- Department of Organic Chemistry, University of Valladolid, Campus Miguel Delibes, 47011 Valladolid, Spain.
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Hughes JME, Gleason JL. A Concise Enantioselective Total Synthesis of (−)-Virosaine A. Angew Chem Int Ed Engl 2017; 56:10830-10834. [DOI: 10.1002/anie.201706273] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Indexed: 11/12/2022]
Affiliation(s)
- Jonathan M. E. Hughes
- Department of Chemistry; McGill University; 801 Sherbrooke W. Montreal QC H3A 0B8 Canada
| | - James L. Gleason
- Department of Chemistry; McGill University; 801 Sherbrooke W. Montreal QC H3A 0B8 Canada
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Hughes JME, Gleason JL. A Concise Enantioselective Total Synthesis of (−)-Virosaine A. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201706273] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Jonathan M. E. Hughes
- Department of Chemistry; McGill University; 801 Sherbrooke W. Montreal QC H3A 0B8 Canada
| | - James L. Gleason
- Department of Chemistry; McGill University; 801 Sherbrooke W. Montreal QC H3A 0B8 Canada
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Szulc BR, Sil BC, Ruiz A, Hilton ST. A Common Precursor Approach to Structurally Diverse Natural Products: The Synthesis of the Core Structure of (±)-Clausenamide and the Total Synthesis of (±)-Hyalodendrin. European J Org Chem 2015. [DOI: 10.1002/ejoc.201501256] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Zipfel HF, Carreira EM. A Unified Strategy to 6-5-6-5-6-Membered Epipolythiodiketopiperazines: Studies towards the Total Synthesis of Scabrosin Diacetate and Haematocin. Chemistry 2015; 21:12475-80. [PMID: 26179159 DOI: 10.1002/chem.201500918] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2015] [Indexed: 11/11/2022]
Abstract
The family of epipolythiodiketopiperazine (ETP) natural products consists of over 200 members possessing a wide diversity of structures and biological activity. Recently, the subgroup of 6-5-6-5-6-membered ETPs has gained substantial attention, which has resulted in several total syntheses. Despite all the efforts that have been invested into accessing these complex structures, no synthesis of scabrosin diacetate (1 a) and its related esters has been reported. Herein, our attempts towards scabrosin diacetate (1 a) and haematocin (3) starting from diketopiperazine 12 a as a late-stage intermediate are presented. Diketopiperazine 12 a can be conveniently accessed in multigram quantities from aldehyde 18 and diketopiperazine 21 and was envisioned to serve as a general platform for the synthesis of 6-5-6-5-6-membered ETPs.
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Affiliation(s)
- Hannes F Zipfel
- Laboratorium für Organische Chemie, Eidgenössische Technische Hochschule Zürich, Vladimir-Prelog-Weg 3, 8093 Zürich (Switzerland)
| | - Erick M Carreira
- Laboratorium für Organische Chemie, Eidgenössische Technische Hochschule Zürich, Vladimir-Prelog-Weg 3, 8093 Zürich (Switzerland).
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Belov DS, Ratmanova NK, Andreev IA, Kurkin AV. Synthesis of bicyclic proline derivatives by the aza-Cope-Mannich reaction: formal synthesis of (±)-acetylaranotin. Chemistry 2015; 21:4141-7. [PMID: 25631763 DOI: 10.1002/chem.201405811] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Indexed: 11/11/2022]
Abstract
Herein we suggest an approach to oxygenated bicyclic amino acids based on an aza-Cope-Mannich rearrangement. Seven distinct amino acid scaffolds analogous to the natural products were prepared on a gram scale with precise control of stereochemistry. Successful implementation of our strategy resulted in the formal synthesis of acetylaranotin.
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Affiliation(s)
- Dmitry S Belov
- Lomonosov Moscow State University, Department of Chemistry, 1/3 Leninskie Gory, Moscow, 119991 (Russia) www.chem.msu.ru; EDASA Scientific srls., Via Stingi, 37, 66050 San Salvo (CH) (Italy) www.edasascientific.com.
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