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Joshi H, Thomas AA, Mague JT, Sathyamoorthi S. Dancing Silanols: Stereospecific Rearrangements of Silanol Epoxides into Silanoxy-Tetrahydrofurans and Silanoxy-Tetrahydropyrans. Org Chem Front 2023; 10:2556-2562. [PMID: 38037597 PMCID: PMC10688609 DOI: 10.1039/d3qo00427a] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2023]
Abstract
We have developed highly stereospecific rearrangements of silanol epoxides into 1'-silanoxy-tetrahydrofurans and 1'-silanoxy-tetrahydropyrans. Upon treatment with Ph3CBF4 and NaHCO3 in CH2Cl2, di-substituted trans-epoxide silanols rearrange into products with an erythro configuration; di-substituted cis-epoxide silanols give products with a threo configuration. We have used these reactions as key steps in the syntheses of (±)-solerone and (±)-muricatacin.
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Affiliation(s)
- Harshit Joshi
- University of Kansas, Department of Medicinal Chemistry, Lawrence, KS, USA (66047)
| | - Annu Anna Thomas
- University of Kansas, Department of Medicinal Chemistry, Lawrence, KS, USA (66047)
| | - Joel T Mague
- Tulane University, Department of Chemistry, New Orleans, LA, USA (70118)
| | - Shyam Sathyamoorthi
- University of Kansas, Department of Medicinal Chemistry, Lawrence, KS, USA (66047)
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2
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Singh M, Yadav LDS, Singh RKP. Direct radical sulfonylation at α-C(sp3)-H of THF with sodium sulfinates in aqueous medium. Tetrahedron Lett 2019. [DOI: 10.1016/j.tetlet.2019.02.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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3
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Reckenthäler M, Neudörfl JM, Zorlu E, Griesbeck AG. Combined Photoredox and Lewis Acid Catalyzed α-Hydroxyalkylation of Cyclic Ethers with Aromatic Ketones. J Org Chem 2016; 81:7211-6. [PMID: 27380313 DOI: 10.1021/acs.joc.6b01085] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The photochemically induced coupling of aromatic ketones with cyclic ethers such as tetrahydrofuran, tetrahydropyran, and 1,4-dioxane was studied. Direct photolysis of the substrates with UV-A light centered at 350 nm does not lead to photoinduced hydrogen transfer whereas the addition of a mixture of the Lewis acid catalysts Ti(O(i)Pr)4 and BF3 enables the formation of the hydroxyalkylation products.
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Affiliation(s)
- Melissa Reckenthäler
- Department of Chemistry, University of Cologne , Greinstr. 4, Cologne D-50939, Germany
| | - Jörg-M Neudörfl
- Department of Chemistry, University of Cologne , Greinstr. 4, Cologne D-50939, Germany
| | - Elif Zorlu
- Department of Chemistry, University of Cologne , Greinstr. 4, Cologne D-50939, Germany
| | - Axel G Griesbeck
- Department of Chemistry, University of Cologne , Greinstr. 4, Cologne D-50939, Germany
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4
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Sølvhøj A, Ahlburg A, Madsen R. Dimethylzinc-Initiated Radical Coupling of β-Bromostyrenes with Ethers and Amines. Chemistry 2015; 21:16272-9. [PMID: 26377614 DOI: 10.1002/chem.201502429] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Indexed: 11/07/2022]
Abstract
A new coupling reaction has been developed in which β-bromostyrenes react with ethers and tertiary amines to introduce the styryl group in the α-position. The transformation is mediated by Me2 Zn/O2 with 10 % MnCl2 and is believed to proceed by a radical addition-elimination mechanism. The ether and the amine are employed as solvent and the coupling takes place through the most stable α radical for unsymmetrical substrates. The products are obtained in moderate to good yields as the pure E isomers. The coupling can be achieved with a range of smaller cyclic and acyclic ethers/amines as well as various substituted β-bromostyrenes.
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Affiliation(s)
- Amanda Sølvhøj
- Department of Chemistry, Technical University of Denmark, 2800 Kgs. Lyngby (Denmark)
| | - Andreas Ahlburg
- Department of Chemistry, Technical University of Denmark, 2800 Kgs. Lyngby (Denmark)
| | - Robert Madsen
- Department of Chemistry, Technical University of Denmark, 2800 Kgs. Lyngby (Denmark).
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5
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Affiliation(s)
- Ken-ichi Yamada
- Graduate School of Pharmaceutical Sciences; Kyoto University; Kyoto Japan
| | - Kiyoshi Tomioka
- Department of Medicinal Chemistry; Faculty of Pharmaceutical Sciences; Doshisha Women's College of Liberal Arts; Kyoto Japan
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6
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Yoshimitsu T. Endeavors to access molecular complexity: strategic use of free radicals in natural product synthesis. CHEM REC 2014; 14:268-79. [PMID: 24677484 DOI: 10.1002/tcr.201300024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Indexed: 01/16/2023]
Abstract
Free radicals, which in the past were considered unruly chemical species, have become manageable and indispensable for synthetic organic chemistry. The unique nature of free radicals has allowed practitioners in organic synthesis to design flexible approaches to produce various materials ranging from small molecules to polymers. The present Personal Account describes the author's endeavors to create molecular complexity by the strategic use of free radicals, with an emphasis on the synthesis of bioactive natural products.
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Affiliation(s)
- Takehiko Yoshimitsu
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka, 565-0871, Japan.
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7
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Ge X, Le Mai Hoang K, Leow ML, Liu XW. Cascade reactions initiated by radical addition of tetrahydrofuran to β-bromonitrostyrenes. RSC Adv 2014. [DOI: 10.1039/c4ra08357a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Silver(i) catalyzed addition of THF radical to β-bromonitrostyrenes under mild basic condition in the presence of air has been developed.
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Affiliation(s)
- Xin Ge
- Division of Chemistry and Biological Chemistry
- School of Physical and Mathematical Sciences
- Nanyang Technological University
- Singapore 637371
| | - Kim Le Mai Hoang
- Division of Chemistry and Biological Chemistry
- School of Physical and Mathematical Sciences
- Nanyang Technological University
- Singapore 637371
| | - Min Li Leow
- Division of Chemistry and Biological Chemistry
- School of Physical and Mathematical Sciences
- Nanyang Technological University
- Singapore 637371
| | - Xue-Wei Liu
- Division of Chemistry and Biological Chemistry
- School of Physical and Mathematical Sciences
- Nanyang Technological University
- Singapore 637371
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8
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Zhang J, Li P, Wang L. KOAc-promoted alkynylation of α-C–H bonds of ethers with alkynyl bromides under transition-metal-free conditions. Org Biomol Chem 2014; 12:2969-78. [DOI: 10.1039/c4ob00002a] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
KOAc-promoted α-position C–H activation and alkynylation of ethers with alkynyl bromides to 2-alkynyl ethers was developed under transition-metal-free conditions.
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Affiliation(s)
- Jiajun Zhang
- Department of Chemistry
- Huaibei Normal University
- Huaibei, P R China
| | - Pinhua Li
- Department of Chemistry
- Huaibei Normal University
- Huaibei, P R China
| | - Lei Wang
- Department of Chemistry
- Huaibei Normal University
- Huaibei, P R China
- State Key Laboratory of Organometallic Chemistry
- Shanghai Institute of Organic Chemistry
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9
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Synthesis of α-di or trisubstituted (tetrahydrofuran-2-yl)methanols via photoinduced additive-free intermolecular addition of THF to aromatic aldehydes or ketones. Tetrahedron Lett 2013. [DOI: 10.1016/j.tetlet.2013.10.063] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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10
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Yamada KI, Konishi T, Nakano M, Fujii S, Cadou R, Yamamoto Y, Tomioka K. Radical One-Pot α,β-Dual and β-Mono-Oxymethylation of Alkylidenemalonate. J Org Chem 2012; 77:5775-80. [DOI: 10.1021/jo300944f] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Ken-ichi Yamada
- Graduate School of Pharmaceutical
Sciences, Kyoto University, Yoshida, Sakyo,
Kyoto 606-8501, Japan
| | - Takehito Konishi
- Graduate School of Pharmaceutical
Sciences, Kyoto University, Yoshida, Sakyo,
Kyoto 606-8501, Japan
| | - Mayu Nakano
- Graduate School of Pharmaceutical
Sciences, Kyoto University, Yoshida, Sakyo,
Kyoto 606-8501, Japan
| | - Shintaro Fujii
- Graduate School of Pharmaceutical
Sciences, Kyoto University, Yoshida, Sakyo,
Kyoto 606-8501, Japan
| | - Romain Cadou
- Graduate School of Pharmaceutical
Sciences, Kyoto University, Yoshida, Sakyo,
Kyoto 606-8501, Japan
| | - Yasutomo Yamamoto
- Faculty
of Pharmaceutical Sciences, Doshisha Women’s College of Liberal Arts, Kodo,
Kyotanabe 610-0395, Japan
| | - Kiyoshi Tomioka
- Faculty
of Pharmaceutical Sciences, Doshisha Women’s College of Liberal Arts, Kodo,
Kyotanabe 610-0395, Japan
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11
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Tortoreto C, Achard T, Zeghida W, Austeri M, Guénée L, Lacour J. Enol Acetal Synthesis through Carbenoid CH Insertion into Tetrahydrofuran Catalyzed by CpRu Complexes. Angew Chem Int Ed Engl 2012; 51:5847-51. [DOI: 10.1002/anie.201201541] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Indexed: 11/09/2022]
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12
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Tortoreto C, Achard T, Zeghida W, Austeri M, Guénée L, Lacour J. Enol Acetal Synthesis through Carbenoid CH Insertion into Tetrahydrofuran Catalyzed by CpRu Complexes. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201201541] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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13
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Zhang SY, Zhang FM, Tu YQ. Direct Sp3α-C–H activation and functionalization of alcohol and ether. Chem Soc Rev 2011; 40:1937-49. [DOI: 10.1039/c0cs00063a] [Citation(s) in RCA: 416] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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14
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Ueda M, Kondoh E, Ito Y, Shono H, Kakiuchi M, Ichii Y, Kimura T, Miyoshi T, Naito T, Miyata O. Benzyl radical addition reaction through the homolytic cleavage of a benzylic C–H bond. Org Biomol Chem 2011; 9:2062-4. [DOI: 10.1039/c0ob01148g] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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16
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Abstract
Developments in modern organic synthesis owe much to the field of radical chemistry. Mild reaction conditions, high selectivity, good functional group tolerance and high product yield are features that have made reactions involving radical species indispensable tools for synthetic chemists. In part, the discovery of new radical initiators has led to the efficiency that now characterizes most radical reactions. This Account describes our investigations of radical reactions initiated by dimethylzinc. In 2001, we unexpectedly observed this reaction while investigating the amidophosphane-copper-catalyzed asymmetric addition of dimethylzinc to N-sulfonyl imines with tetrahydrofuran (THF) as reaction solvent. However, instead of adding the desired methyl group to the N-sulfonyl imine, we produced the THF adduct in excellent yield. This result laid the foundation for our discovery of novel modes of reactivity. Further investigations of the unexpected addition reaction revealed that a trace amount of air was needed for reaction progress, indicating that radical intermediates were involved. Indeed, controlled injection of air into the reaction flask by a syringe pump through a sodium hydroxide tube afforded the products in good to excellent yield. In addition, the reaction proved to be chemoselective for a C=N bond over a C=O bond, as well as for 1,4-addition over 1,2-addition. We developed asymmetric variants of the radical addition reaction of ethers to imines using chiral N-sulfinyl imines to produce the adducts in reasonably high stereoselectivity (up to 11:1). A 93:7 diastereomeric ratio of the adduct was obtained when bis(8-phenylmenthyl) benzylidenemalonate was used in the radical addition of ethers to C=C bonds. Interestingly, in the presence of dimethylzinc and air, arylamines, alkoxyamines, and dialkylhydrazines react with THF to give amino alcohols, oximes, and hydrazones, respectively, in moderate to high yields. We performed a tin-free intermolecular addition of functionalized primary alkyl groups, generated from their corresponding iodides, to N-sulfonyl imines using dimethylzinc, air, boron trifluoride diethyl etherate, and a catalytic amount of copper(II) triflate. Direct C-H bond cleavage from cycloalkanes was also feasible in the presence of dimethylzinc, air, and boron trifluoride diethyl etherate to give the corresponding cycloalkyl radicals, which were suitable nucleophiles for N-sulfonyl imines. In all of the above reactions, dimethylzinc was a superior radical initiator than other conventional initiators such as dibenzoyl peroxide, diethylzinc, and triethylborane. We hope the coming decades will witness the report of other novel radical initiators that would complement the reactivity modes of existing ones.
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Affiliation(s)
- Tito Akindele
- Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan
| | - Ken-ichi Yamada
- Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan
| | - Kiyoshi Tomioka
- Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan
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Yamada KI, Maekawa M, Akindele T, Nakano M, Yamamoto Y, Tomioka K. Chemoselective Conjugate Addition of Dimethylzinc-Mediated Ether and Acetal Radicals to Alkylidenemalonates and Asymmetric Reactions. J Org Chem 2008; 73:9535-8. [DOI: 10.1021/jo801541m] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ken-ichi Yamada
- Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan
| | - Masaru Maekawa
- Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan
| | - Tito Akindele
- Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan
| | - Mayu Nakano
- Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan
| | - Yasutomo Yamamoto
- Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan
| | - Kiyoshi Tomioka
- Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan
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18
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Affiliation(s)
- John P. Wolfe
- Department of Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, MI, 48109-1055
| | - Michael B. Hay
- Department of Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, MI, 48109-1055
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Ahn MY, Filley TR, Jafvert CT, Nies L, Hua I. Birnessite mediated debromination of decabromodiphenyl ether. CHEMOSPHERE 2006; 64:1801-7. [PMID: 16545423 DOI: 10.1016/j.chemosphere.2006.02.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2005] [Revised: 01/30/2006] [Accepted: 02/02/2006] [Indexed: 05/07/2023]
Abstract
Decabromodiphenyl ether (BDE-209) is a major component of a commercial flame retardant formulation; however, there is limited information on the fate of BDE-209 in the environment, including metal oxide mediated degradation. Laboratory experiments were conducted to investigate the birnessite (delta-MnO(2))-promoted debromination of BDE-209 in tetrahydrofuran (THF)-water systems as well as catechol solutions. Up to 100% (0.1044 micromol initial charge) of BDE-209 disappeared upon reaction with birnessite in THF/H(2)O (4:6-9:1). The formation of aqueous Br(-) from BDE-209 reduction was determined and up to 16 mole% of initial bromine was released over the course of the reaction indicating approximately 1.7 Br-C bonds were reduced per BDE-209 molecule. The distribution of debrominated congeners, however, indicated a much greater extent of debromination for some products than what was inferred from an average bromine mass balance. The produced congeners varied from tetra- to nona-bromodiphenyl ether, including BDE-47 and -99, during the 24 h reaction. Experiments with deuterated water indicated that water was not the major hydrogen donor in the reduction but rather THF provided the reducing power. This conclusion was supported by the presence of succinic acid, which was produced from oxidation of THF. The reactions with aqueous catechol, rather than THF-water mixtures, were performed to assess the possible role that compounds found in natural environments, such a tannin-like phenols, might have on the chemistry. These experiments indicated that birnessite mediated debromination of BDE-209 might occur in natural settings.
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Affiliation(s)
- Mi-Youn Ahn
- Department of Earth and Atmospheric Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, IN 47907, USA.
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Yamamoto Y, Maekawa M, Akindele T, Yamada KI, Tomioka K. Dimethylzinc-initiated radical reaction of cyclic ethers with arylamines, alkoxyamines, and dialkylhydrazines. Tetrahedron 2005. [DOI: 10.1016/j.tet.2004.10.080] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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21
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Chapter 5.3 Five-membered ring systems: Furans and benzofurans. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/s0959-6380(05)80049-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Abstract
(+)-Muconin (1), isolated from the leaves of Rollinia mucosa (Jacq.) Baill. (Annonaceae), is a sequential THF/THP-possessing acetogenin that exhibits potent and selective in vitro cytotoxicity toward pancreatic and breast tumor cell lines. In this study, a new route was established for obtaining (+)-muconin (1) starting with (-)-muricatacin (2), a compound recently synthesized via the novel alpha-C-H hydroxyalkylation and alpha'-C-H oxidation of tetrahydrofuran.
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Affiliation(s)
- Takehiko Yoshimitsu
- Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan.
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Yamamoto Y, Yamada KI, Tomioka K. Unexpected reaction of a dimethylzinc-generated THF radical with aldehydes. Tetrahedron Lett 2004. [DOI: 10.1016/j.tetlet.2003.11.037] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Yoshimitsu T, Makino T, Nagaoka H. Synthesis of (--)-Muricatacin via alpha- and alpha'-C-H bond functionalization of tetrahydrofuran. J Org Chem 2003; 68:7548-50. [PMID: 12968919 DOI: 10.1021/jo0301696] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
(--)-Muricatacin, a potent cytotoxic (4R,5R)-5-hydroxyheptadecan-4-olide, has been synthesized through alpha-C--H hydroxyalkylation and alpha'-C--H oxidation of tetrahydrofuran. This study presents a novel method for C--H bond functionalization as a means for preparing gamma-(hydroxyalkyl)-gamma-butyrolactones.
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Affiliation(s)
- Takehiko Yoshimitsu
- Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan.
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