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Evans DA, Beiger JJ, Burch JD, Fuller PH, Glorius F, Kattnig E, Thaisrivongs DA, Trenkle WC, Young JM, Zhang J. Total Synthesis of Aflastatin A. J Am Chem Soc 2022; 144:19953-19972. [PMID: 36269121 DOI: 10.1021/jacs.2c08244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The total syntheses of aflastatin A and its C3-C48 degradation fragment (6a, R = H) have been accomplished. The syntheses feature several complex diastereoselective fragment couplings, including a Felkin-selective trityl-catalyzed Mukaiyama aldol reaction, a chelate-controlled aldol reaction involving soft enolization with magnesium, and an anti-Felkin-selective boron-mediated oxygenated aldol reaction. Careful comparison of the spectroscopic data for the synthetic C3-C48 degradation fragment to that reported by the isolation group revealed a structural misassignment in the lactol region of the naturally derived degradation product. Ultimately, the data reported for the naturally derived aflastatin A C3-C48 degradation lactol (6a, R = H) were attributed to its derivative lactol trideuteriomethyl ether (6c, R = CD3). Additionally, the revised absolute configurations of six stereogenic centers (C8, C9, and C28-C31) were confirmed.
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Affiliation(s)
- David A Evans
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Jason J Beiger
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Jason D Burch
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Peter H Fuller
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Frank Glorius
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Egmont Kattnig
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - David A Thaisrivongs
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - William C Trenkle
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Joseph M Young
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Jing Zhang
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
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Cordes M, Kalesse M. Very Recent Advances in Vinylogous Mukaiyama Aldol Reactions and Their Applications to Synthesis. Molecules 2019; 24:molecules24173040. [PMID: 31443344 PMCID: PMC6749529 DOI: 10.3390/molecules24173040] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 08/15/2019] [Accepted: 08/19/2019] [Indexed: 02/07/2023] Open
Abstract
It is a challenging objective in synthetic organic chemistry to create efficient access to biologically active compounds. In particular, one structural element which is frequently incorporated into the framework of complex natural products is a β-hydroxy ketone. In this context, the aldol reaction is the most important transformation to generate this structural element as it not only creates new C-C bonds but also establishes stereogenic centers. In recent years, a large variety of highly selective methodologies of aldol and aldol-type reactions have been put forward. In this regard, the vinylogous Mukaiyama aldol reaction (VMAR) became a pivotal transformation as it allows the synthesis of larger fragments while incorporating 1,5-relationships and generating two new stereocenters and one double bond simultaneously. This review summarizes and updates methodology-oriented and target-oriented research focused on the various aspects of the vinylogous Mukaiyama aldol (VMA) reaction. This manuscript comprehensively condenses the last four years of research, covering the period 2016-2019.
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Affiliation(s)
- Martin Cordes
- Institute of Organic Chemistry, Gottfried Wilhelm Leibniz University of Hannover, Schneiderberg 1b, 30167 Hannover, Germany
| | - Markus Kalesse
- Institute of Organic Chemistry, Gottfried Wilhelm Leibniz University of Hannover, Schneiderberg 1b, 30167 Hannover, Germany.
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