1
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Reetz MT. Dyotropic Rearrangements in Organic Solvents, in the Gas Phase, and in Enzyme Catalysis. Isr J Chem 2023. [DOI: 10.1002/ijch.202200122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Manfred T. Reetz
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim Germany
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences Tianjin 300308 China
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2
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Benford‐Ward J, Ahmadipour S, Sembayeva A, Male L, Grainger RS. Studies towards the Synthesis of (+)‐Dictyoxetane. Chemistry 2022; 28:e202202429. [PMID: 36300909 PMCID: PMC10092742 DOI: 10.1002/chem.202202429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Indexed: 11/06/2022]
Abstract
The dolabellane-type diterpene dictyoxetane represents a significant challenge to synthetic organic chemistry. Methodology directed towards the total synthesis of naturally occurring (+)-dictyoxetane is reported. Catalytic asymmetric synthesis of the trans-hydrindane ring system is achieved through chemoselective deoxygenation of the Hajos-Parrish ketone. An alternative to the Garst-Spencer furan annulation is developed for the synthesis of a 2,5-dimethyl, tetrasubstituted furan, employing a tandem 5-exo-dig alcohol to alkyne cyclisation/aromatisation reaction as a key step. The (4+3) cycloaddition reaction of an oxyallyl cation with a tetrasubstituted furan is established on a cyclohexanone-derived model system, and a range of related (4+3) cycloadditions investigated on a homochiral, trans-hydrindane-fused furan, where regio- and diastereoselectivity is required for the natural product synthesis. In an alternative (4+2) Diels-Alder approach, a C2 -symmetric vinyl sulfoxide-based chiral ketene equivalent is used to prepare oxanorbornenes with the same oxygen bridge stereochemistry found in the 2,7-dioxatricyclo[4.2.1.03,8 ]nonane ring system of the natural product.
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Affiliation(s)
- Joseph Benford‐Ward
- School of Chemistry University of Birmingham Edgbaston Birmingham B15 2TT UK
| | - Sanaz Ahmadipour
- School of Chemistry University of Birmingham Edgbaston Birmingham B15 2TT UK
| | - Aliya Sembayeva
- School of Chemistry University of Birmingham Edgbaston Birmingham B15 2TT UK
| | - Louise Male
- School of Chemistry University of Birmingham Edgbaston Birmingham B15 2TT UK
| | - Richard S. Grainger
- School of Chemistry University of Birmingham Edgbaston Birmingham B15 2TT UK
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3
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Bartolo ND, Demkiw KM, Read JA, Valentín EM, Yang Y, Dillon AM, Hu CT, Ward MD, Woerpel KA. Conformationally Biased Ketones React Diastereoselectively with Allylmagnesium Halides. J Org Chem 2022; 87:3042-3065. [PMID: 35167300 PMCID: PMC9022492 DOI: 10.1021/acs.joc.1c02844] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The addition of the highly reactive reagent allylmagnesium halide to α-substituted acyclic chiral ketones proceeded with high stereoselectivity. The stereoselectivity cannot be analyzed by conventional stereochemical models because these reactions do not conform to the requirements of those models. Instead, the stereoselectivity arises from the approach of the nucleophile to the most accessible diastereofaces of the lowest-energy conformations of the ketones. High stereoselectivity is expected, and the stereochemical outcome can be predicted, with conformationally biased ketones that have sterically distinguishable diastereofaces wherein only one face is accessible for nucleophilic addition. The conformations of the ketones can be determined by a combination of computational modeling and, in some cases, structure determination by X-ray crystallography.
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Affiliation(s)
- Nicole D. Bartolo
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003 USA
| | - Krystyna M. Demkiw
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003 USA
| | - Jacquelyne A. Read
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003 USA
| | | | - Yingying Yang
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003 USA
| | - Alexandra M. Dillon
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003 USA
| | - Chunhua T. Hu
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003 USA
| | - Michael D. Ward
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003 USA
| | - K. A. Woerpel
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003 USA
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4
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Malarney KP, Kc S, Schmidt VA. Recent strategies used in the synthesis of saturated four-membered heterocycles. Org Biomol Chem 2021; 19:8425-8441. [PMID: 34546272 DOI: 10.1039/d1ob00988e] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The importance and prevalance of O-, N-, and S-atom containing saturated four-membered ring motifs in biologically active molecules and potential therapeutics continues to drive efforts in their efficient synthetic preparation. In this review, general and recent strategies for the synthesis of these heterocycles are presented. Due to the limited potential bond disconnections, retrosynthetic strategies are broadly limited to cyclizations and cycloadditions. Nonetheless, diverse approaches for accessing cyclization precursors have been developed, ranging from nucleophilic substitution to C-H functionalization. Innovative methods for substrate activation have been developed for cycloadditions under photochemical and thermal conditions. Advances in accessing oxetanes, azetidines, and thietanes remain active areas of research with continued breakthroughs anticipated to enable future applications.
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Affiliation(s)
- Kien P Malarney
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, 92071, USA.
| | - Shekhar Kc
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, 92071, USA.
| | - Valerie A Schmidt
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, 92071, USA.
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5
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Bartolo ND, Demkiw KM, Valentín EM, Hu CT, Arabi AA, Woerpel KA. Diastereoselective Additions of Allylmagnesium Reagents to α-Substituted Ketones When Stereochemical Models Cannot Be Used. J Org Chem 2021; 86:7203-7217. [PMID: 33978419 DOI: 10.1021/acs.joc.1c00553] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The stereoselectivities of reactions of allylmagnesium reagents with chiral ketones cannot be easily explained by stereochemical models. Competition experiments indicate that the complexation step is not reversible, so nucleophiles cannot access the widest range of possible encounter complexes and therefore cannot be analyzed easily using available models. Nevertheless, additions of allylmagnesium reagents to a ketone can still be stereoselective provided that the carbonyl group adopts a conformation that leads to one face being completely blocked from the approach of the allylmagnesium reagent.
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Affiliation(s)
- Nicole D Bartolo
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003, United States
| | - Krystyna M Demkiw
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003, United States
| | - Elizabeth M Valentín
- St. Mary's College of California, 1928 St. Marys Road, Moraga, California 94575, United States
| | - Chunhua T Hu
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003, United States
| | - Alya A Arabi
- Biochemistry Department, College of Medicine and Health Sciences, United Arab Emirates University, P.O. Box 17666, Al Ain, United Arab Emirates.,Centre for Computational Science, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - K A Woerpel
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY 10003, United States
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6
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Hjerrild P, Tørring T, Poulsen TB. Dehydration reactions in polyfunctional natural products. Nat Prod Rep 2020; 37:1043-1064. [DOI: 10.1039/d0np00009d] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Here, we review methods for chemical dehydration of alcohols to alkenes and discuss the potential of late-stage functionalization by direct, site- and chemo-selective dehydration of complex molecular substrates.
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Affiliation(s)
- Per Hjerrild
- Department of Chemistry
- Aarhus University
- DK-8000 Aarhus C
- Denmark
| | - Thomas Tørring
- Department of Engineering – Microbial Biosynthesis
- Aarhus University
- Aarhus C
- Denmark
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7
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Wein LA, Wurst K, Angyal P, Weisheit L, Magauer T. Synthesis of (-)-Mitrephorone A via a Bioinspired Late Stage C-H Oxidation of (-)-Mitrephorone B. J Am Chem Soc 2019; 141:19589-19593. [PMID: 31770485 DOI: 10.1021/jacs.9b11646] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We present a bioinspired late-stage C-H oxidation of the ent-trachylobane natural product mitrephorone B to mitrephorone A. The realization of this unprecedented transformation was accomplished by either an iron-catalyzed or electrochemical oxidation and enabled access to the densely substituted oxetane in one step. Formation of mitrephorone C, which is lacking the central oxetane unit but features a keto-function at C2, was not formed under these conditions.
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Affiliation(s)
- Lukas Anton Wein
- Institute of Organic Chemistry and Center for Molecular Biosciences , Leopold-Franzens-University Innsbruck , Innrain 80-82 , 6020 Innsbruck , Austria
| | - Klaus Wurst
- Institute of General, Inorganic and Theoretical Chemistry , Leopold-Franzens-University Innsbruck , Innrain 80-82 , 6020 Innsbruck , Austria
| | - Peter Angyal
- Institute of Organic Chemistry , Research Centre for Natural Sciences , Magyar tudósok körútja 2 , 1117 Budapest , Hungary
| | - Lara Weisheit
- Institute of Organic Chemistry and Center for Molecular Biosciences , Leopold-Franzens-University Innsbruck , Innrain 80-82 , 6020 Innsbruck , Austria
| | - Thomas Magauer
- Institute of Organic Chemistry and Center for Molecular Biosciences , Leopold-Franzens-University Innsbruck , Innrain 80-82 , 6020 Innsbruck , Austria
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8
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Lu Q, Harmalkar DS, Choi Y, Lee K. An Overview of Saturated Cyclic Ethers: Biological Profiles and Synthetic Strategies. Molecules 2019; 24:molecules24203778. [PMID: 31640154 PMCID: PMC6833478 DOI: 10.3390/molecules24203778] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 10/18/2019] [Accepted: 10/19/2019] [Indexed: 12/18/2022] Open
Abstract
Saturated oxygen heterocycles are widely found in a broad array of natural products and other biologically active molecules. In medicinal chemistry, small and medium rings are also important synthetic intermediates since they can undergo ring-opening and -expansion reactions. These applications have driven numerous studies on the synthesis of oxygen-containing heterocycles and considerable effort has been devoted toward the development of methods for the construction of saturated oxygen heterocycles. This paper provides an overview of the biological roles and synthetic strategies of saturated cyclic ethers, covering some of the most studied and newly discovered related natural products in recent years. This paper also reports several promising and newly developed synthetic methods, emphasizing 3-7 membered rings.
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Affiliation(s)
- Qili Lu
- College of Pharmacy, Dongguk University-Seoul, Goyang 10326, Korea.
| | - Dipesh S Harmalkar
- College of Pharmacy, Dongguk University-Seoul, Goyang 10326, Korea.
- College of Life Sciences and Biotechnology, Korea University, Seoul 02841, Korea.
| | - Yongseok Choi
- College of Life Sciences and Biotechnology, Korea University, Seoul 02841, Korea.
| | - Kyeong Lee
- College of Pharmacy, Dongguk University-Seoul, Goyang 10326, Korea.
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9
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Hugelshofer CL, Palani V, Sarpong R. Calyciphylline B-type Alkaloids: Evolution of a Synthetic Strategy to (−)-Daphlongamine H. J Org Chem 2019; 84:14069-14091. [DOI: 10.1021/acs.joc.9b02223] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Cedric L. Hugelshofer
- Department of Chemistry, University of California Berkeley, Berkeley, California 94720, United States
| | - Vignesh Palani
- Department of Chemistry, University of California Berkeley, Berkeley, California 94720, United States
| | - Richmond Sarpong
- Department of Chemistry, University of California Berkeley, Berkeley, California 94720, United States
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10
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Palani V, Hugelshofer CL, Sarpong R. A Unified Strategy for the Enantiospecific Total Synthesis of Delavatine A and Formal Synthesis of Incarviatone A. J Am Chem Soc 2019; 141:14421-14432. [DOI: 10.1021/jacs.9b07693] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Vignesh Palani
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
| | - Cedric L. Hugelshofer
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
| | - Richmond Sarpong
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
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11
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Kutateladze AG, Holt T, Reddy DS. Natural Products Containing the Oxetane and Related Moieties Present Additional Challenges for Structure Elucidation: A DU8+ Computational Case Study. J Org Chem 2019; 84:7575-7586. [DOI: 10.1021/acs.joc.9b01005] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Andrei G. Kutateladze
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado 80208, United States
| | - Tina Holt
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado 80208, United States
| | - D. Sai Reddy
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado 80208, United States
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12
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Richter MJR, Schneider M, Brandstätter M, Krautwald S, Carreira EM. Total Synthesis of (-)-Mitrephorone A. J Am Chem Soc 2018; 140:16704-16710. [PMID: 30412398 DOI: 10.1021/jacs.8b09685] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The first synthesis of (-)-mitrephorone A is disclosed along with discussion and study of synthetic strategies. The natural product includes a highly congested hexacyclic ent-trachylobane diterpenoid framework featuring a rare, embedded oxetane. The synthetic analysis presented dissects a number of approaches for the synthesis of the central oxetane, including carbonyl-olefin photocycloadditions, Prins-type cyclizations, and oxidative ring closures. In the successful route, three [4 + 2] cycloadditions enable rapid construction of all carbocycles. A novel late-stage oxidative cyclization of a hydroxy diosphenol with Koser's reagent furnishes the pivotal oxetane moiety.
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Affiliation(s)
| | | | | | - Simon Krautwald
- ETH Zürich , Vladimir-Prelog-Weg 3, HCI , 8093 Zürich , Switzerland
| | - Erick M Carreira
- ETH Zürich , Vladimir-Prelog-Weg 3, HCI , 8093 Zürich , Switzerland
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13
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Ma B, Zhao Y, He C, Ding H. Total Synthesis of an Atropisomer of the
Schisandra
Triterpenoid Schiglautone A. Angew Chem Int Ed Engl 2018; 57:15567-15571. [DOI: 10.1002/anie.201809076] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Indexed: 12/14/2022]
Affiliation(s)
- Binjie Ma
- Department of ChemistryZhejiang University Hangzhou 310058 China
| | - Yifan Zhao
- Department of ChemistryZhejiang University Hangzhou 310058 China
| | - Chi He
- Department of ChemistryZhejiang University Hangzhou 310058 China
| | - Hanfeng Ding
- Department of ChemistryZhejiang University Hangzhou 310058 China
- State Key Laboratory of Elemento-Organic ChemistryNankai University Tianjin 300071 China
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14
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Ma B, Zhao Y, He C, Ding H. Total Synthesis of an Atropisomer of the
Schisandra
Triterpenoid Schiglautone A. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201809076] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Binjie Ma
- Department of ChemistryZhejiang University Hangzhou 310058 China
| | - Yifan Zhao
- Department of ChemistryZhejiang University Hangzhou 310058 China
| | - Chi He
- Department of ChemistryZhejiang University Hangzhou 310058 China
| | - Hanfeng Ding
- Department of ChemistryZhejiang University Hangzhou 310058 China
- State Key Laboratory of Elemento-Organic ChemistryNankai University Tianjin 300071 China
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15
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The chemistry of the carbon-transition metal double and triple bond: Annual survey covering the year 2016. Coord Chem Rev 2018. [DOI: 10.1016/j.ccr.2017.09.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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16
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Abstract
Covering: 2016. Previous review: Nat. Prod. Rep., 2017, 34, 235-294This review covers the literature published in 2016 for marine natural products (MNPs), with 757 citations (643 for the period January to December 2016) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms. The emphasis is on new compounds (1277 in 432 papers for 2016), together with the relevant biological activities, source organisms and country of origin. Reviews, biosynthetic studies, first syntheses, and syntheses that led to the revision of structures or stereochemistries, have been included.
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Affiliation(s)
- John W Blunt
- School of Physical and Chemical Sciences, University of Canterbury, Christchurch, New Zealand
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17
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Affiliation(s)
- Shu-An Liu
- Department
of Chemistry and Center for Integrated Protein Science, Ludwig-Maximilian University Munich, Butenandtstraße 5-13, 81377 Munich, Germany
| | - Dirk Trauner
- Department
of Chemistry and Center for Integrated Protein Science, Ludwig-Maximilian University Munich, Butenandtstraße 5-13, 81377 Munich, Germany
- Department
of Chemistry, New York University, 100 Washington Square East, New York, New York 10003, United States
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18
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Sevenich A, Liu GQ, Arduengo AJ, Gupton BF, Opatz T. Asymmetric One-Pot Synthesis of (3R,3aS,6aR)-Hexahydrofuro[2,3-b]furan-3-ol: A Key Component of Current HIV Protease Inhibitors. J Org Chem 2017; 82:1218-1223. [DOI: 10.1021/acs.joc.6b02588] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Adrian Sevenich
- Institute
of Organic Chemistry, Johannes Gutenberg University, Duesbergweg 10−14, 55128 Mainz, Germany
| | - Gong-Qing Liu
- Institute
of Organic Chemistry, Johannes Gutenberg University, Duesbergweg 10−14, 55128 Mainz, Germany
| | - Anthony J. Arduengo
- Department
of Chemistry, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - B. Frank Gupton
- Department
of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284, United States
| | - Till Opatz
- Institute
of Organic Chemistry, Johannes Gutenberg University, Duesbergweg 10−14, 55128 Mainz, Germany
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19
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Hugelshofer CL, Magauer T. Dyotropic rearrangements in natural product total synthesis and biosynthesis. Nat Prod Rep 2017; 34:228-234. [DOI: 10.1039/c7np00005g] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Some recent examples of dyotropic rearrangements involved in complex natural product total synthesis and biosynthesis are highlighted.
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Affiliation(s)
| | - Thomas Magauer
- Department of Chemistry and Pharmacy
- Ludwig-Maximilians-Univeristy Munich
- 81377 Munich
- Germany
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20
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Abstract
Some recent examples of conceptually different bioinspired total syntheses of complex terpenoids are presented that highlight the numerous benefits of pursuing bioinspired strategies.
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Affiliation(s)
- Cedric L. Hugelshofer
- Department of Chemistry and Pharmacy
- Ludwig-Maximilians-University Munich
- 81377 Munich
- Germany
| | - Thomas Magauer
- Department of Chemistry and Pharmacy
- Ludwig-Maximilians-University Munich
- 81377 Munich
- Germany
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21
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Speck K, Wildermuth R, Magauer T. Convergent Assembly of the Tetracyclic Meroterpenoid (−)-Cyclosmenospongine by a Non-Biomimetic Polyene Cyclization. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201608040] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Klaus Speck
- Department of Chemistry and Pharmacy; Ludwig Maximilians University Munich; Butenandtstrasse 5-13 81377 Munich Germany
| | - Raphael Wildermuth
- Department of Chemistry and Pharmacy; Ludwig Maximilians University Munich; Butenandtstrasse 5-13 81377 Munich Germany
| | - Thomas Magauer
- Department of Chemistry and Pharmacy; Ludwig Maximilians University Munich; Butenandtstrasse 5-13 81377 Munich Germany
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22
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Speck K, Wildermuth R, Magauer T. Convergent Assembly of the Tetracyclic Meroterpenoid (-)-Cyclosmenospongine by a Non-Biomimetic Polyene Cyclization. Angew Chem Int Ed Engl 2016; 55:14131-14135. [PMID: 27730742 DOI: 10.1002/anie.201608040] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Indexed: 11/12/2022]
Abstract
The cationic cyclization of polyenes constitutes a powerful and elegant transformation, which has been utilized by nature's biosynthetic machinery for the construction of complex polycyclic terpenoids. Previous studies by chemists to mimic this cyclization in the laboratory were limited to different modes of activation using biosynthetic-like precursors, which accommodate only simple methyl-derived substituents. Here we describe the development of an unprecedented and highly efficient polyene cyclization of an aryl enol ether containing substrate. The cyclization was shown to proceed in a stepwise manner to generate three rings and three consecutive stereocenters, two of which are tetrasubstituted, in a single flask. The developed transformation is of great synthetic value and has enabled the convergent assembly of the tetracyclic meroterpenoid (-)-cyclosmenospongine.
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Affiliation(s)
- Klaus Speck
- Department of Chemistry and Pharmacy, Ludwig Maximilians University Munich, Butenandtstrasse 5-13, 81377, Munich, Germany
| | - Raphael Wildermuth
- Department of Chemistry and Pharmacy, Ludwig Maximilians University Munich, Butenandtstrasse 5-13, 81377, Munich, Germany
| | - Thomas Magauer
- Department of Chemistry and Pharmacy, Ludwig Maximilians University Munich, Butenandtstrasse 5-13, 81377, Munich, Germany.
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23
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Hugelshofer CL, Magauer T. A Divergent Approach to the Marine Diterpenoids (+)-Dictyoxetane and (+)-Dolabellane V. Chemistry 2016; 22:15125-15136. [DOI: 10.1002/chem.201603061] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Indexed: 12/26/2022]
Affiliation(s)
- Cedric L. Hugelshofer
- Department of Chemistry and Pharmacy; Ludwig-Maximilians-University Munich; Butenandtstrasse 5-13 81377 Munich Germany
| | - Thomas Magauer
- Department of Chemistry and Pharmacy; Ludwig-Maximilians-University Munich; Butenandtstrasse 5-13 81377 Munich Germany
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