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Matsumura T, Nishikawa T, Nakazaki A. Total Synthesis of 19-Nordigitoxigenin, An Antiaroside Y Aglycon. J Org Chem 2023; 88:15142-15150. [PMID: 37824414 DOI: 10.1021/acs.joc.3c01629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2023]
Abstract
The first total synthesis of 19-nordigitoxigenin, an aglycon of antiroside Y, has been achieved. The key steps of our synthesis are (i) construction of the 19-norsteroid ring system via a Mizoroki-Heck reaction between a bromoanisole corresponding to the A-ring and cyclic alkene incorporating the CD-rings, followed by a Friedel-Crafts-type cyclodehydration, and (ii) incorporation of the butenolide moiety at C17 via a silyl-tethered radical cyclization and subsequent ozone oxidation.
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Affiliation(s)
- Taishi Matsumura
- Graduate School of Bioagricultural Sciences, Nagoya University Furo-cho, Chikusa, Nagoya 464-8601, Japan
| | - Toshio Nishikawa
- Graduate School of Bioagricultural Sciences, Nagoya University Furo-cho, Chikusa, Nagoya 464-8601, Japan
| | - Atsuo Nakazaki
- Graduate School of Bioagricultural Sciences, Nagoya University Furo-cho, Chikusa, Nagoya 464-8601, Japan
- Faculty of Science and Engineering, Iwate University, Ueda, Morioka 020-8551, Japan
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Omar YM, Santucci G, Afarinkia K. tert-Butyl(2-oxo-2 H-pyran-5-yl)carbamate as the First Chameleon Diene Bearing an Electron-Donating Substituent. Molecules 2022; 27:molecules27175666. [PMID: 36080432 PMCID: PMC9458009 DOI: 10.3390/molecules27175666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 08/10/2022] [Accepted: 08/29/2022] [Indexed: 11/16/2022] Open
Abstract
The 2(H)-pyran-2-one bearing electron-donating tert-butylcarbamate (BocNH-) group at the 5- position is a “chameleon” diene and undergoes efficient Diels–Alder cycloadditions with alkene dienophiles with both electron-rich and electron-deficient substituents. Cycloadditions afford the 5-substituted bicyclic lactone cycloadducts regardless of the electronic nature of the dienophile. However, cycloadditions with electronically matched electron-deficient dienophiles proceed faster than those with electronically mismatched electron-rich dienophiles.
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Affiliation(s)
- Yasser M. Omar
- Institute of Cancer Therapeutics, University of Bradford, Bradford BD7 1DP, UK
- Department Pharmaceutical Organic Chemistry, Faculty of Pharmacy, Assiut University, Assiut 71526, Egypt
| | - Giulia Santucci
- Department Pharmaceutical Organic Chemistry, Faculty of Pharmacy, Assiut University, Assiut 71526, Egypt
| | - Kamyar Afarinkia
- Institute of Cancer Therapeutics, University of Bradford, Bradford BD7 1DP, UK
- School of Biomedical Sciences, University of West London, London W5 5RF, UK
- Correspondence:
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Dobler D, Leitner M, Moor N, Reiser O. 2‐Pyrone – A Privileged Heterocycle and Widespread Motif in Nature. European J Org Chem 2021. [DOI: 10.1002/ejoc.202101112] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Daniel Dobler
- Institut für Organische Chemie Universität Regensburg Universitätsstr. 31 93053 Regensburg Germany
| | - Michael Leitner
- Institut für Organische Chemie Universität Regensburg Universitätsstr. 31 93053 Regensburg Germany
| | - Natalija Moor
- Institut für Organische Chemie Universität Regensburg Universitätsstr. 31 93053 Regensburg Germany
| | - Oliver Reiser
- Institut für Organische Chemie Universität Regensburg Universitätsstr. 31 93053 Regensburg Germany
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Points GL, Beaudry CM. Regioselective Synthesis of Substituted Carbazoles, Bicarbazoles, and Clausine C. Org Lett 2021; 23:6882-6885. [PMID: 34424701 DOI: 10.1021/acs.orglett.1c02449] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Substituted carbazoles are efficiently constructed from 3-triflato-2-pyrones and alkynyl anilines. Multiple substituents are tolerated on the carbazole, and complete control of regiochemistry is observed. Complicated and sterically congested substitution patterns are produced. This strategy is also used to prepare substituted bicarbazoles and related biaryls. Finally, the method was showcased in a synthesis of the carbazole natural product clausine C.
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Affiliation(s)
- Gary L Points
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331, United States
| | - Christopher M Beaudry
- Department of Chemistry, Oregon State University, 153 Gilbert Hall, Corvallis, Oregon 97331, United States
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Abstract
This article describes a concise synthesis of cardiotonic steroids oleandrigenin (7) and its subsequent elaboration into the natural product rhodexin B (2) from the readily available intermediate (8) that could be derived from the commercially available steroids testosterone or DHEA via three-step sequences. These studies feature an expedient installation of the β16-oxidation based on β14-hydroxyl-directed epoxidation and subsequent epoxide rearrangement. The following singlet oxygen oxidation of the C17 furan moiety provides access to oleandrigenin (7) in 12 steps (LLS) and a 3.1% overall yield from 8. The synthetic oleandrigenin (7) was successfully glycosylated with l-rhamnopyranoside-based donor 28 using a Pd(II)-catalyst, and the subsequent deprotection under acidic conditions provided cytotoxic natural product rhodexin B (2) in a 66% yield (two steps).
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Affiliation(s)
- Zachary Fejedelem
- Chemistry Department, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
| | - Nolan Carney
- Chemistry Department, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
| | - Pavel Nagorny
- Chemistry Department, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
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Watanabe S, Nishikawa T, Nakazaki A. Total Synthesis of the Cardiotonic Steroid (+)-Cannogenol. J Org Chem 2021; 86:3605-3614. [PMID: 33538172 DOI: 10.1021/acs.joc.0c02966] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The total synthesis of (+)-cannogenol, an aglycon common to various biologically important cardiotonic glycosides, has been achieved. Synthesis of the versatile intermediate involves Mizoroki-Heck and intramolecular Diels-Alder reactions from the enantiomerically pure CD-ring segment, newly prepared in a multidecagram scale this time. Total synthesis by the site-selective transformations of the versatile intermediate demonstrated the applicability of our synthetic approach.
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Affiliation(s)
- Shogo Watanabe
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8601, Japan
| | - Toshio Nishikawa
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8601, Japan
| | - Atsuo Nakazaki
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8601, Japan
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Gayyur, Choudhary S, Saxena A, Ghosh N. Gold-catalyzed homo- and cross-annulation of alkynyl carboxylic acids: a facile access to substituted 4-hydroxy 2 H-pyrones and total synthesis of pseudopyronine A. Org Biomol Chem 2020; 18:8716-8723. [PMID: 33089263 DOI: 10.1039/d0ob01700k] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A Au(i)-catalyzed homo- and cross-annulation reaction of alkynyl carboxylic acids offering 3,6-disubstituted 4-hydroxy 2H-pyrones has been demonstrated. The reaction tolerates various substituted alkynyl carboxylic acids and moderate to good yields of α-pyrone scaffolds have been observed. Later, a gram-scale reaction of the acid and the total synthesis of the natural product pseudopyronine A have been carried out successfully.
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Affiliation(s)
- Gayyur
- Division of Medicinal and Process Chemistry, CSIR-Central Drug Research Institute, Lucknow-226031, U.P., India.
| | - Shivani Choudhary
- Division of Medicinal and Process Chemistry, CSIR-Central Drug Research Institute, Lucknow-226031, U.P., India.
| | - Anchal Saxena
- Division of Medicinal and Process Chemistry, CSIR-Central Drug Research Institute, Lucknow-226031, U.P., India.
| | - Nayan Ghosh
- Division of Medicinal and Process Chemistry, CSIR-Central Drug Research Institute, Lucknow-226031, U.P., India. and Academy of Scientific & Innovative Research (AcSIR), Ghaziabad-201002, U. P., India
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Mies T, Ma TK, Barrett AGM. Syntheses of polyfunctional aromatic compounds from non-aromatic precursors. RUSSIAN CHEMICAL REVIEWS 2020. [DOI: 10.1070/rcr4931] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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