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Ali R, Ahmed W, Jayant V, alvi S, Ahmed N, Ahmed A. Metathesis reactions in total‐ and natural product fragments syntheses. ASIAN J ORG CHEM 2022. [DOI: 10.1002/ajoc.202100753] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Rashid Ali
- Jamia Millia Islamia New Delhi India 110025 Department of Chemistry Jamia Nagar,New Delhi india110025 110025 New Delhi INDIA
| | - Waqar Ahmed
- Jamia Millia Islamia Central University: Jamia Millia Islamia Chemistry INDIA
| | - Vikrant Jayant
- Jamia Millia Islamia Central University: Jamia Millia Islamia Chemistry INDIA
| | - shakeel alvi
- Jamia Millia Islamia Central University: Jamia Millia Islamia Chemistry INDIA
| | - Nadeem Ahmed
- Jamia Millia Islamia Central University: Jamia Millia Islamia Chemistry INDIA
| | - Azeem Ahmed
- Jamia Millia Islamia Central University: Jamia Millia Islamia Chemistry INDIA
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Heinrich M, Murphy JJ, Ilg MK, Letort A, Flasz JT, Philipps P, Fürstner A. Chagosensine: A Riddle Wrapped in a Mystery Inside an Enigma. J Am Chem Soc 2020; 142:6409-6422. [PMID: 32142305 PMCID: PMC7307910 DOI: 10.1021/jacs.0c01700] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Indexed: 01/02/2023]
Abstract
The marine macrolide chagosensine is supposedly distinguished by a (Z,Z)-configured 1,3-chlorodiene contained within a highly strained 16-membered lactone ring, which also incorporates two trans-2,5-disubstituted tetrahydrofuran (THF) rings; this array is unique. After our initial synthesis campaign had shown that the originally proposed structure is incorrect, the published data set was critically revisited to identify potential mis-assignments. The "northern" THF ring and the anti-configured diol in the "southern" sector both seemed to be sites of concern, thus making it plausible that a panel of eight diastereomeric chagosensine-like compounds would allow the puzzle to be solved. To meet the challenge, the preparation of the required building blocks was optimized, and a convergent strategy for their assembly was developed. A key role was played by the cobalt-catalyzed oxidative cyclization of alken-5-ol derivatives ("Mukaiyama cyclization"), which is shown to be exquisitely chemoselective for terminal alkenes, leaving even terminal alkynes (and other sites of unsaturation) untouched. Likewise, a palladium-catalyzed alkyne alkoxycarbonylation reaction with formation of an α-methylene-γ-lactone proved instrumental, which had not found application in natural product synthesis before. Further enabling steps were a nickel-catalyzed "Tamaru-type" homocrotylation, stereodivergent aldehyde homologations, radical hydroindation, and palladium-catalyzed alkyne-1,2-bis-stannation. The different building blocks were assembled in a serial fashion to give the idiosyncratic chlorodienes by an unprecedented site-selective Stille coupling followed by copper-mediated tin/chlorine exchange. The macrolactones were closed under forcing Yamaguchi conditions, and the resulting products were elaborated into the targeted compound library. Yet, only one of the eight diastereomers turned out to be stable in the solvent mixture that had been used to analyze the natural product; all other isomers were prone to ring opening and/or ring expansion. In addition to this stability issue, our self-consistent data set suggests that chagosensine has almost certainly little to do with the structure originally proposed by the isolation team.
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Affiliation(s)
| | | | - Marina K. Ilg
- Max-Planck-Institut für
Kohlenforschung, D-45470 Mülheim/Ruhr, Germany
| | - Aurélien Letort
- Max-Planck-Institut für
Kohlenforschung, D-45470 Mülheim/Ruhr, Germany
| | - Jakub T. Flasz
- Max-Planck-Institut für
Kohlenforschung, D-45470 Mülheim/Ruhr, Germany
| | - Petra Philipps
- Max-Planck-Institut für
Kohlenforschung, D-45470 Mülheim/Ruhr, Germany
| | - Alois Fürstner
- Max-Planck-Institut für
Kohlenforschung, D-45470 Mülheim/Ruhr, Germany
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3
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Zeng X, Sun J, Liu C, Ji C, Peng Y. Catalytic Asymmetric Cyanation Reactions of Aldehydes and Ketones in Total Synthesis. Adv Synth Catal 2019. [DOI: 10.1002/adsc.201900015] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Xing‐Ping Zeng
- Key Laboratory of Small Functional Organic MoleculeMinistry of EducationJiangxi Normal University Nanchang Jiangxi 330022 People's Republic of China
| | - Jun‐Chao Sun
- Key Laboratory of Small Functional Organic MoleculeMinistry of EducationJiangxi Normal University Nanchang Jiangxi 330022 People's Republic of China
| | - Chao Liu
- Key Laboratory of Small Functional Organic MoleculeMinistry of EducationJiangxi Normal University Nanchang Jiangxi 330022 People's Republic of China
| | - Cong‐Bin Ji
- Jiangxi Provincial Research of Targeting Pharmaceutical Engineering TechnologyShangrao Normal University Shangrao Jiangxi 334001 People's Republic of China
| | - Yi‐Yuan Peng
- Key Laboratory of Small Functional Organic MoleculeMinistry of EducationJiangxi Normal University Nanchang Jiangxi 330022 People's Republic of China
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Mountanea OG, Limnios D, Kokotou MG, Bourboula A, Kokotos G. Asymmetric Synthesis of Saturated Hydroxy Fatty Acids and Fatty Acid Esters of Hydroxy Fatty Acids. European J Org Chem 2019. [DOI: 10.1002/ejoc.201801881] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Olga G. Mountanea
- Laboratory of Organic Chemistry; Department of Chemistry; National and Kapodistrian University of Athens; Panepistimiopolis Athens 15771 Greece
| | - Dimitris Limnios
- Laboratory of Organic Chemistry; Department of Chemistry; National and Kapodistrian University of Athens; Panepistimiopolis Athens 15771 Greece
| | - Maroula G. Kokotou
- Laboratory of Organic Chemistry; Department of Chemistry; National and Kapodistrian University of Athens; Panepistimiopolis Athens 15771 Greece
| | - Asimina Bourboula
- Laboratory of Organic Chemistry; Department of Chemistry; National and Kapodistrian University of Athens; Panepistimiopolis Athens 15771 Greece
| | - George Kokotos
- Laboratory of Organic Chemistry; Department of Chemistry; National and Kapodistrian University of Athens; Panepistimiopolis Athens 15771 Greece
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Heinrich M, Murphy JJ, Ilg MK, Letort A, Flasz J, Philipps P, Fürstner A. Total Synthesis of Putative Chagosensine. Angew Chem Int Ed Engl 2018; 57:13575-13581. [PMID: 30152031 DOI: 10.1002/anie.201808937] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Indexed: 12/22/2022]
Abstract
The marine macrolide chagosensine is the only natural product known to date that embodies a Z,Z-configured chloro-1,3-diene unit. This distinguishing substructure was prepared by a sequence of palladium-catalyzed 1,2-distannation of an alkyne precursor, regioselective Stille cross-coupling at the terminus of the resulting bisstannyl alkene with an elaborated alkenyl iodide, followed by chloro-destannation of the remaining internal site. The preparation of the required substrates centered on cobalt-catalyzed oxidative cyclization reactions of hydroxylated olefin precursors, which allowed the 2,5-trans-disubstituted tetrahydrofuran rings, embedded into each building block, to be formed with excellent selectivity. The highly strained macrolactone could ultimately be closed under forcing Yamaguchi conditions. Comparison of the spectral data of the synthetic sample with those of authentic chagosensine methyl ester confirmed that the structure of this intriguing compound has been mis-assigned by the isolation team.
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Affiliation(s)
- Marc Heinrich
- Max-Planck-Institut für Kohlenforschung, 45470, Mülheim/Ruhr, Germany
| | - John J Murphy
- Max-Planck-Institut für Kohlenforschung, 45470, Mülheim/Ruhr, Germany
| | - Marina K Ilg
- Max-Planck-Institut für Kohlenforschung, 45470, Mülheim/Ruhr, Germany
| | - Aurélien Letort
- Max-Planck-Institut für Kohlenforschung, 45470, Mülheim/Ruhr, Germany
| | - Jakub Flasz
- Max-Planck-Institut für Kohlenforschung, 45470, Mülheim/Ruhr, Germany
| | - Petra Philipps
- Max-Planck-Institut für Kohlenforschung, 45470, Mülheim/Ruhr, Germany
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung, 45470, Mülheim/Ruhr, Germany
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Abdel-Mawgoud AM, Stephanopoulos G. Simple glycolipids of microbes: Chemistry, biological activity and metabolic engineering. Synth Syst Biotechnol 2018; 3:3-19. [PMID: 29911195 PMCID: PMC5884252 DOI: 10.1016/j.synbio.2017.12.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 11/14/2017] [Accepted: 12/04/2017] [Indexed: 01/15/2023] Open
Abstract
Glycosylated lipids (GLs) are added-value lipid derivatives of great potential. Besides their interesting surface activities that qualify many of them to act as excellent ecological detergents, they have diverse biological activities with promising biomedical and cosmeceutical applications. Glycolipids, especially those of microbial origin, have interesting antimicrobial, anticancer, antiparasitic as well as immunomodulatory activities. Nonetheless, GLs are hardly accessing the market because of their high cost of production. We believe that experience of metabolic engineering (ME) of microbial lipids for biofuel production can now be harnessed towards a successful synthesis of microbial GLs for biomedical and other applications. This review presents chemical groups of bacterial and fungal GLs, their biological activities, their general biosynthetic pathways and an insight on ME strategies for their production.
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Affiliation(s)
| | - Gregory Stephanopoulos
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139, USA
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Nallasivam JL, Fernandes RA. A protecting-group-free synthesis of (+)-nephrosteranic, (+)-protolichesterinic, (+)-nephrosterinic, (+)-phaseolinic, (+)-rocellaric acids and (+)-methylenolactocin. Org Biomol Chem 2017; 15:708-716. [DOI: 10.1039/c6ob02398c] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A collective synthesis of a γ-butyrolactone class of paraconic acids such as (+)-methylenolactocin, (+)-phaseolinic acid, (+)-nephrosteranic acid, (+)-nephrosterinic acid, (+)-rocellaric acid and (+)-protolichesterinic acid is described.
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Affiliation(s)
- Jothi L. Nallasivam
- Department of Chemistry
- Indian Institute of Technology Bombay
- Mumbai 400 076
- India
| | - Rodney A. Fernandes
- Department of Chemistry
- Indian Institute of Technology Bombay
- Mumbai 400 076
- India
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Schaubach S, Gebauer K, Ungeheuer F, Hoffmeister L, Ilg MK, Wirtz C, Fürstner A. A Two-Component Alkyne Metathesis Catalyst System with an Improved Substrate Scope and Functional Group Tolerance: Development and Applications to Natural Product Synthesis. Chemistry 2016; 22:8494-507. [DOI: 10.1002/chem.201601163] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Indexed: 01/02/2023]
Affiliation(s)
| | - Konrad Gebauer
- Max-Planck-Institut für Kohlenforschung; 45470 Mülheim/Ruhr Germany
| | - Felix Ungeheuer
- Max-Planck-Institut für Kohlenforschung; 45470 Mülheim/Ruhr Germany
| | | | - Marina K. Ilg
- Max-Planck-Institut für Kohlenforschung; 45470 Mülheim/Ruhr Germany
| | - Conny Wirtz
- Max-Planck-Institut für Kohlenforschung; 45470 Mülheim/Ruhr Germany
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung; 45470 Mülheim/Ruhr Germany
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Abstract
AbstractIn enantioselective reactions, the major, desired enantiomer is commonly obtained along with the minor, undesired enantiomer. By continuous recycling of this undesired enantiomer back to starting material, products with improved enantiomeric purity can be obtained. Such in situ minor enantiomer recycling can be accomplished by coupling the catalytic reaction to an exergonic transformation of a sacrificial reagent. The method has been applied to the synthesis of O-acylated cyanohydrins, which serve as starting materials for a variety of biologically active compounds.
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Affiliation(s)
- Christina Moberg
- 1KTH Royal Institute of Technology, Department of Chemistry, Organic Chemistry, SE 10044 Stockholm, Sweden
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Laurell Nash A, Hertzberg R, Wen YQ, Dahlgren B, Brinck T, Moberg C. Dual Lewis Acid/Lewis Base Catalyzed Acylcyanation of Aldehydes: A Mechanistic Study. Chemistry 2016; 22:3821-9. [PMID: 26592522 DOI: 10.1002/chem.201503782] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Indexed: 11/07/2022]
Abstract
A mechanistic investigation, which included a Hammett correlation analysis, evaluation of the effect of variation of catalyst composition, and low-temperature NMR spectroscopy studies, of the Lewis acid-Lewis base catalyzed addition of acetyl cyanide to prochiral aldehydes provides support for a reaction route that involves Lewis base activation of the acyl cyanide with formation of a potent acylating agent and cyanide ion. The cyanide ion adds to the carbonyl group of the Lewis acid activated aldehyde. O-Acylation by the acylated Lewis base to form the final cyanohydrin ester occurs prior to decomplexation from titanium. For less reactive aldehydes, the addition of cyanide is the rate-determining step, whereas, for more reactive, electron-deficient aldehydes, cyanide addition is rapid and reversible and is followed by rate-limiting acylation. The resting state of the catalyst lies outside the catalytic cycle and is believed to be a monomeric titanium complex with two alcoholate ligands, which only slowly converts into the product.
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Affiliation(s)
- Anna Laurell Nash
- KTH Royal Institute of Technology, Department of Chemistry, Organic Chemistry, 10044, Stockholm, Sweden
| | - Robin Hertzberg
- KTH Royal Institute of Technology, Department of Chemistry, Organic Chemistry, 10044, Stockholm, Sweden
| | - Ye-Qian Wen
- KTH Royal Institute of Technology, Department of Chemistry, Organic Chemistry, 10044, Stockholm, Sweden
| | - Björn Dahlgren
- KTH Royal Institute of Technology, Department of Chemistry, Applied Physical Chemistry, 10044, Stockholm, Sweden
| | - Tore Brinck
- KTH Royal Institute of Technology, Department of Chemistry, Applied Physical Chemistry, 10044, Stockholm, Sweden
| | - Christina Moberg
- KTH Royal Institute of Technology, Department of Chemistry, Organic Chemistry, 10044, Stockholm, Sweden
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Bénéteau R, Despiau CF, Rouaud J, Boussonnière A, Silvestre V, Lebreton J, Dénès F. Synthesis of Polysubstituted γ‐Butenolides via a Radical Pathway: Cyclization of α‐Bromo Aluminium Acetals and Comparison with the Cyclization of α‐Bromoesters at High Temperature. Chemistry 2015; 21:11378-86. [DOI: 10.1002/chem.201501294] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Indexed: 11/06/2022]
Affiliation(s)
- Romain Bénéteau
- CEISAM UMR 6230 ‐ UFR des Sciences et des Techniques, Université de Nantes, 2 rue de la Houssiniere BP 92208‐44322, Nantes Cedex 3 (France)
| | - Carole F. Despiau
- CEISAM UMR 6230 ‐ UFR des Sciences et des Techniques, Université de Nantes, 2 rue de la Houssiniere BP 92208‐44322, Nantes Cedex 3 (France)
| | - Jean‐Christophe Rouaud
- CEISAM UMR 6230 ‐ UFR des Sciences et des Techniques, Université de Nantes, 2 rue de la Houssiniere BP 92208‐44322, Nantes Cedex 3 (France)
| | - Anne Boussonnière
- CEISAM UMR 6230 ‐ UFR des Sciences et des Techniques, Université de Nantes, 2 rue de la Houssiniere BP 92208‐44322, Nantes Cedex 3 (France)
- Current Address: Université du Maine and CNRS UMR 6283, Institut des Molécules et Matériaux du Mans, Faculté des Sciences et Techniques, avenue Olivier Messiaen, 72085 Le Mans Cedex 9 (France)
| | - Virginie Silvestre
- CEISAM UMR 6230 ‐ UFR des Sciences et des Techniques, Université de Nantes, 2 rue de la Houssiniere BP 92208‐44322, Nantes Cedex 3 (France)
| | - Jacques Lebreton
- CEISAM UMR 6230 ‐ UFR des Sciences et des Techniques, Université de Nantes, 2 rue de la Houssiniere BP 92208‐44322, Nantes Cedex 3 (France)
| | - Fabrice Dénès
- CEISAM UMR 6230 ‐ UFR des Sciences et des Techniques, Université de Nantes, 2 rue de la Houssiniere BP 92208‐44322, Nantes Cedex 3 (France)
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Willwacher J, Heggen B, Wirtz C, Thiel W, Fürstner A. Total Synthesis, Stereochemical Revision, and Biological Reassessment of Mandelalide A: Chemical Mimicry of Intrafamily Relationships. Chemistry 2015; 21:10416-30. [PMID: 26094957 DOI: 10.1002/chem.201501491] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Indexed: 11/06/2022]
Abstract
Mandelalide A and three congeners had recently been isolated as the supposedly highly cytotoxic principles of an ascidian collected off the South African coastline. Since these compounds are hardly available from the natural source, a concise synthesis route was developed, targeting structure 1 as the purported representation of mandelalide A. The sequence involves an iridium-catalyzed two-directional Krische allylation and a cobalt-catalyzed carbonylative epoxide opening as entry points for the preparation of the major building blocks. The final stages feature the first implementation of terminal acetylene metathesis into natural product total synthesis, which is remarkable in that this class of substrates had been beyond the reach of alkyne metathesis for decades. Synthetic 1, however, proved not to be identical with the natural product. In an attempt to clarify this issue, NMR spectra were simulated for 20 conceivable diastereomers by using DFT followed by DP4 analysis; however, this did not provide a reliable assignment either. The puzzle was ultimately solved by the preparation of three diastereomers, of which compound 6 proved identical with mandelalide A in all analytical and spectroscopic regards. As the entire "northern sector" about the tetrahydrofuran ring in 6 shows the opposite configuration of what had originally been assigned, it is highly likely that the stereostructures of the sister compounds mandelalides B-D must be corrected analogously; we propose that these natural products are accurately represented by structures 68-70. In an attempt to prove this reassignment, an entry into mandelalides C and D was sought by subjecting an advanced intermediate of the synthesis of 6 to a largely unprecedented intramolecular Morita-Baylis-Hillman reaction, which furnished the γ-lactone derivative 74 as a mixture of diastereomers. Whereas (24R)-74 was amenable to a hydroxyl-directed dihydroxylation by using OsO4 /TMEDA as the reagent, the sister compound (24S)-74 did not follow a directed path but simply obeyed Kishi's rule; only this unexpected escape precluded the preparation of mandelalides C and D by this route. A combined spectroscopic and computational (DFT) study showed that the reasons for this strikingly different behavior of the two diastereomers of 74 are rooted in their conformational peculiarities. This aspect apart, our results show that the OsO4 /TMEDA complex reacts preferentially with electron deficient double bonds even if other alkenes are present that are more electron rich and less encumbered. Finally, in a brief biological survey authentic mandelalide A (6) was found to exhibit appreciable cytotoxicity only against one out of three tested human cancer cell lines and all synthetic congeners were hardly active. No significant fungicidal properties were observed.
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Affiliation(s)
- Jens Willwacher
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr (Germany)
| | - Berit Heggen
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr (Germany)
| | - Conny Wirtz
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr (Germany)
| | - Walter Thiel
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr (Germany)
| | - Alois Fürstner
- Max-Planck-Institut für Kohlenforschung, 45470 Mülheim/Ruhr (Germany).
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The chemistry of the carbon-transition metal double and triple bond: Annual survey covering the year 2013. Coord Chem Rev 2015. [DOI: 10.1016/j.ccr.2014.09.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Zhao YM, Maimone TJ. Short, enantioselective total synthesis of chatancin. Angew Chem Int Ed Engl 2015; 54:1223-6. [PMID: 25470723 PMCID: PMC4300267 DOI: 10.1002/anie.201410443] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Indexed: 11/06/2022]
Abstract
An enantioselective total synthesis of the polycyclic diterpene (+)-chatancin, a potent PAF antagonist, is reported. Proceeding in seven steps from dihydrofarnesal, this synthetic route was designed to circumvent macrocyclization-based strategies to complex, cyclized cembranoids. The described synthesis requires only six chromatographic purifications, is high yielding, and avoids protecting-group manipulations. An X-ray crystal structure of this fragile marine natural product was obtained.
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Affiliation(s)
- Yu-Ming Zhao
- Department of Chemistry, University of California, Berkeley, 826 Latimer Hall, Berkeley, CA 94720 (USA)
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Fürstner A. Catalysis for Total Synthesis: A Personal Account. Angew Chem Int Ed Engl 2014; 53:8587-98. [DOI: 10.1002/anie.201402719] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2014] [Indexed: 01/09/2023]
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Willwacher J, Fürstner A. Catalysis-Based Total Synthesis of Putative Mandelalide A. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201400605] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Willwacher J, Fürstner A. Catalysis-Based Total Synthesis of Putative Mandelalide A. Angew Chem Int Ed Engl 2014; 53:4217-21. [DOI: 10.1002/anie.201400605] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Indexed: 12/26/2022]
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Sharif EU, Wang HYL, Akhmedov NG, O’Doherty GA. Merremoside D: de novo synthesis of the purported structure, NMR analysis, and comparison of spectral data. Org Lett 2014; 16:492-5. [PMID: 24354696 PMCID: PMC4078405 DOI: 10.1021/ol403369h] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The first synthesis of the purported structure of Merremoside D has been achieved in 22 longest linear steps. The de novo asymmetric synthesis relied on the use of asymmetric catalysis to selectively install all 21 stereocenters in the final compounds from commercially available achiral starting materials. Adiabatic gradient 2D NMR techniques (gHSQCAD, gHMBCAD, gH2BCAD, gHSQCTOXYAD, ROESYAD) were used to completely assign the structure of synthetic Merremoside D. Comparison of our assignments with the limited NMR data reported for natural Merremoside D allows for the tentative confirmation of its structure.
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Affiliation(s)
- Ehesan U. Sharif
- Dept of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115
| | - Hua-Yu Leo Wang
- Dept of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115
| | | | - George A. O’Doherty
- Dept of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115
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Bajaj SO, Sharif EU, Akhmedov NG, O'Doherty GA. De novo asymmetric synthesis of the mezzettiaside family of natural products via the iterative use of a dual B-/Pd-catalyzed glycosylation. Chem Sci 2014; 5:2230-2234. [PMID: 25729559 DOI: 10.1039/c4sc00593g] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The first synthesis of any and all members of the mezzettiaside family of natural products has been achieved. The reported synthesis features the iterative use of the Taylor catalyst in a dual nucleophilic boron/electrophilic palladium catalyzed regioselective glycosylation. In addition, the de novo approach utilizes atomless protecting groups and the minimal use of protecting groups (2 chloroacetates for the synthesis of 10 natural products). These divergent syntheses occurred in a range of 13 to 22 longest linear steps and required only 41 total steps to prepare the entire family of mezzettiasides.
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Affiliation(s)
- Sumit O Bajaj
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115
| | - Ehesan U Sharif
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115
| | - Novruz G Akhmedov
- Department of Chemistry, West Virginia University, Morgantown, WV 26506
| | - George A O'Doherty
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115
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Hertzberg R, Moberg C. One-step preparation of O-(α-bromoacyl) cyanohydrins by minor enantiomer recycling: synthesis of 4-amino-2(5H)-furanones. J Org Chem 2013; 78:9174-80. [PMID: 23980631 DOI: 10.1021/jo401401c] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
O-(α-Bromoacyl) cyanohydrins were prepared in a single step from a range of different aldehydes in combination with α-bromoacyl cyanides. By the use of a cyclic procedure where the two minor diastereoisomers from a chiral Lewis acid-catalyzed reaction undergo Candida antarctica lipase B (CALB)-catalyzed hydrolysis followed by dehydrocyanation to regenerate the starting material, the products were obtained in good to high yields and in most cases with excellent diastereoselectivites. The synthetic importance of these compounds was demonstrated by the synthesis of 4-amino-2(5H)-furanones, a class of compounds that have shown both biological activity and utility as synthetic intermediates. This transformation was achieved by an intramolecular Blaise reaction, which gave the products in high to excellent yields and enantiomeric ratios.
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Affiliation(s)
- Robin Hertzberg
- Organic Chemistry, Department of Chemistry, KTH Royal Institute of Technology , SE 100 44 Stockholm, Sweden
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Zhu SY, Huang JS, Zheng SS, Zhu K, Yang JS. First total synthesis of the proposed structure of batatin VI. Org Lett 2013; 15:4154-7. [PMID: 23898788 DOI: 10.1021/ol4020255] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The first total synthesis of batatin VI, an architecturally novel resin glycoside dimer, has been achieved via a convergent [5 + 3] glycosidic coupling approach. An improved protocol for the construction of the key 18-membered macrolactone core using a Keck macrolactonization method was introduced. However, the synthesized compound was not identical to the natural batatin VI.
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Affiliation(s)
- San-Yong Zhu
- Key Laboratory of Drug Targeting and Drug Delivery Systems of the Ministry of Education, Department of Chemistry of Medicinal Natural Products, West China School of Pharmacy, Sichuan University, Chengdu 610041, China
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