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Sarkar S, Sarkar P, Samanta D, Pati SK, Rath SP. Cooperativity in Diiron(III)porphyrin Dication Diradical-Catalyzed Oxa-Diels–Alder Reactions: Spectroscopic and Mechanistic Insights. ACS Catal 2022. [DOI: 10.1021/acscatal.2c02479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sabyasachi Sarkar
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Pallavi Sarkar
- Theoretical Sciences Unit, School of Advanced Materials (SAMat), Jawaharlal Nehru Center for Advanced Scientific Research, Bangalore 560064, India
| | - Deepannita Samanta
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Swapan K Pati
- Theoretical Sciences Unit, School of Advanced Materials (SAMat), Jawaharlal Nehru Center for Advanced Scientific Research, Bangalore 560064, India
| | - Sankar Prasad Rath
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
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2
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Padhi B, Reddy GS, Mallampudi NA, Choudhury UM, Mohapatra DK. CuBr 2-catalyzed diastereoselective allylation: total synthesis of decytospolides A and B and their C6-epimers. Org Biomol Chem 2020; 18:2685-2695. [PMID: 32202577 DOI: 10.1039/c9ob02689d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An efficient CuBr2-catalyzed diastereoselective allylation of a cyclic hemiacetal with allyltrimethylsilane as a nucleophile has been developed. The protocol offers a cost effective, protecting group tolerant, and operationally simple approach to 2,6-trans-disubstituted tetrahydropyran with excellent diastereoselectivity. Furthermore, the application of this methodology has been demonstrated in the total synthesis of decytospolides A and B and their C6-epimers.
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Affiliation(s)
- Birakishore Padhi
- Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad-500007, India.
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3
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Affiliation(s)
- Kylie A. Agnew‐Francis
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane, Queensland Australia 4072
| | - Craig M. Williams
- School of Chemistry and Molecular Biosciences The University of Queensland Brisbane, Queensland Australia 4072
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4
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Zou X, Yang L, Liu X, Sun H, Lu H. Silver Tetrafluoroborate-Catalyzed Oxa-Diels-Alder Reaction Between Electrically Neutral Dienes and Aldehydes. Adv Synth Catal 2015. [DOI: 10.1002/adsc.201500487] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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5
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Carneiro VM, Trivella DB, Scorsato V, Beraldo VL, Dias MP, Sobreira TJ, Aparicio R, Pilli RA. Is RK-682 a promiscuous enzyme inhibitor? Synthesis and in vitro evaluation of protein tyrosine phosphatase inhibition of racemic RK-682 and analogues. Eur J Med Chem 2015; 97:42-54. [DOI: 10.1016/j.ejmech.2015.04.036] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 03/05/2015] [Accepted: 04/16/2015] [Indexed: 10/23/2022]
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6
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Heravi MM, Ahmadi T, Ghavidel M, Heidari B, Hamidi H. Recent applications of the hetero Diels–Alder reaction in the total synthesis of natural products. RSC Adv 2015. [DOI: 10.1039/c5ra17488k] [Citation(s) in RCA: 109] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The synthetic utility and potential power of the Diels–Alder (D–A) reaction in organic chemistry is evident.
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Affiliation(s)
| | | | | | | | - Hoda Hamidi
- Department of Chemistry
- Alzahra University
- Tehran
- Iran
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7
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8
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Kuntiyong P, Lee TH, Kranemann CL, White JD. Total synthesis of the marine toxin phorboxazole A using palladium(II)-mediated intramolecular alkoxycarbonylation for tetrahydropyran synthesis. Org Biomol Chem 2012; 10:7884-99. [PMID: 22910851 DOI: 10.1039/c2ob25766a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The potent antitumor agent phorboxazole A was synthesized from six subunits comprising C1-C2 (115), C3-C8 (98), C9-C19 (74), C20-C32 (52), C33-C41 (84) and C42-C46 (85). Tetrahydropyrans B and C containing cis-2,6-disubstitution were fabricated via palladium(II)-mediated intramolecular alkoxycarbonylation which, in the case of tetrahydropyran C, was carried out with catalytic palladium(II) and p-benzoquinone as the stoichiometric re-oxidant. Tetrahydropyran D was obtained by a stereoselective tin(IV)-catalyzed coupling of a C9 aldehyde with an allylsilane, and the C19-C20 connection was made using a completely stereoselective Wittig-Schlosser (E) olefination. Coupling of the oxazole C32 methyl substituent with the intact C33-C46 δ-lactone 3was accompanied by elimination of the vinyl bromide to a terminal alkyne, but the C32-C33 linkage was implemented successfully with 83 and C33-C41 lactone 84. The C42-C46 segment of the side chain was then appended via Julia-Kocienski olefination. The macrolide portion of phorboxazole A was completed by means of an Ando-Still-Gennari intramolecular (Z)-selective olefination at C2-C3 which required placement of a (dimethoxyphosphinyl)acetate moiety at C24. Final deprotection led to phorboxazole A via a route in which the longest linear sequence is 37 steps and the overall yield is 0.36%.
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Affiliation(s)
- Punlop Kuntiyong
- Department of Chemistry, Oregon State University, Corvallis, Oregon, USA
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9
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Fujiwara K, Kurahashi T, Matsubara S. Cationic Iron(III) Porphyrin-Catalyzed [4 + 2] Cycloaddition of Unactivated Aldehydes with Simple Dienes. J Am Chem Soc 2012; 134:5512-5. [DOI: 10.1021/ja300790x] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kyohei Fujiwara
- Department
of Material Chemistry, Graduate School of
Engineering, Kyoto University, Kyoto 615-8510,
Japan
| | - Takuya Kurahashi
- Department
of Material Chemistry, Graduate School of
Engineering, Kyoto University, Kyoto 615-8510,
Japan
| | - Seijiro Matsubara
- Department
of Material Chemistry, Graduate School of
Engineering, Kyoto University, Kyoto 615-8510,
Japan
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10
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Commandeur C, Florent JC, Rousselle P, Bertounesque E. Easy Access to Pyranoacridines, Pyranoxanthenes, and Arylchromenes Through a Domino Reaction. European J Org Chem 2011. [DOI: 10.1002/ejoc.201001598] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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11
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Clarke PA, Santos S, Mistry N, Burroughs L, Humphries AC. The Asymmetric Maitland−Japp Reaction and Its Application to the Construction of the C1−C19 Bis-pyran Unit of Phorboxazole B. Org Lett 2011; 13:624-7. [DOI: 10.1021/ol102860r] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Paul A. Clarke
- Department of Chemistry, University of York, Heslington, York, YO10 5DD, U.K., and Department of Chemistry, AstraZeneca R&D Charnwood, Bakewell Road, Loughborough, Leicestershire, LE11 5RH, U.K
| | - Soraia Santos
- Department of Chemistry, University of York, Heslington, York, YO10 5DD, U.K., and Department of Chemistry, AstraZeneca R&D Charnwood, Bakewell Road, Loughborough, Leicestershire, LE11 5RH, U.K
| | - Nimesh Mistry
- Department of Chemistry, University of York, Heslington, York, YO10 5DD, U.K., and Department of Chemistry, AstraZeneca R&D Charnwood, Bakewell Road, Loughborough, Leicestershire, LE11 5RH, U.K
| | - Laurence Burroughs
- Department of Chemistry, University of York, Heslington, York, YO10 5DD, U.K., and Department of Chemistry, AstraZeneca R&D Charnwood, Bakewell Road, Loughborough, Leicestershire, LE11 5RH, U.K
| | - Alexander C. Humphries
- Department of Chemistry, University of York, Heslington, York, YO10 5DD, U.K., and Department of Chemistry, AstraZeneca R&D Charnwood, Bakewell Road, Loughborough, Leicestershire, LE11 5RH, U.K
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12
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Díaz-Oltra S, Angulo-Pachón CA, Murga J, Falomir E, Carda M, Marco JA. Synthesis and biological properties of the cytotoxic 14-membered macrolides aspergillide A and B. Chemistry 2010; 17:675-88. [PMID: 21207589 DOI: 10.1002/chem.201001682] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2010] [Revised: 09/03/2010] [Indexed: 11/07/2022]
Abstract
Total, stereoselective syntheses of the naturally occurring, cytotoxic macrolides aspergillide A and B are described. Olefin metatheses and asymmetric allylations were key steps in the synthetic sequences. Cytotoxicity assays against several tumor cell lines have been performed for the two aspergillides and some of the intermediates or side products of the synthetic sequence. One of these intermediates has been found markedly active against the human leukemia cancer cell line HL-60, with an IC(50) value comparable with that of the clinical drug fludarabine.
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Affiliation(s)
- Santiago Díaz-Oltra
- Depart. de Q. Inorgánica y Orgánica, Univ. Jaume I, Avda. Sos Baynat s/n, 12071 Castellón, Spain
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13
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McGowan MA, Stevenson CP, Schiffler MA, Jacobsen EN. An enantioselective total synthesis of (+)-peloruside A. Angew Chem Int Ed Engl 2010; 49:6147-50. [PMID: 20586089 PMCID: PMC2993561 DOI: 10.1002/anie.201002177] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Meredeth A. McGowan
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St., Cambridge, MA 02138
| | - Christian P. Stevenson
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St., Cambridge, MA 02138
| | - Matthew A. Schiffler
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St., Cambridge, MA 02138
| | - Eric N. Jacobsen
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St., Cambridge, MA 02138, Fax: (+1) 617-496-1880
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14
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McGowan M, Stevenson C, Schiffler M, Jacobsen E. An Enantioselective Total Synthesis of (+)-Peloruside A. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.201002177] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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15
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16
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Fu F, Loh TP. An asymmetric synthesis of the polyol fragment of the polyene macrolide antibiotic RK-397. Tetrahedron Lett 2009. [DOI: 10.1016/j.tetlet.2009.03.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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17
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18
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Synthesis of six-membered oxygenated heterocycles through carbon–oxygen bond-forming reactions. Tetrahedron 2008. [DOI: 10.1016/j.tet.2007.11.092] [Citation(s) in RCA: 212] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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19
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Smith AB, Razler TM, Ciavarri JP, Hirose T, Ishikawa T, Meis RM. A Second-Generation Total Synthesis of (+)-Phorboxazole A. J Org Chem 2008; 73:1192-200. [DOI: 10.1021/jo7018152] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Amos B. Smith
- Department of Chemistry, The Penn Center for Molecular Discovery, and Monell Chemical Senses Center, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Thomas M. Razler
- Department of Chemistry, The Penn Center for Molecular Discovery, and Monell Chemical Senses Center, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Jeffrey P. Ciavarri
- Department of Chemistry, The Penn Center for Molecular Discovery, and Monell Chemical Senses Center, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Tomoyasu Hirose
- Department of Chemistry, The Penn Center for Molecular Discovery, and Monell Chemical Senses Center, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Tomoyasu Ishikawa
- Department of Chemistry, The Penn Center for Molecular Discovery, and Monell Chemical Senses Center, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Regina M. Meis
- Department of Chemistry, The Penn Center for Molecular Discovery, and Monell Chemical Senses Center, University of Pennsylvania, Philadelphia, Pennsylvania 19104
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20
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Smith AB, Razler TM, Meis RM, Pettit GR. Synthesis and Biological Evaluation of Phorboxazole Congeners Leading to the Discovery and Preparative-Scale Synthesis of (+)-Chlorophorboxazole A Possessing Picomolar Human Solid Tumor Cell Growth Inhibitory Activity. J Org Chem 2008; 73:1201-8. [DOI: 10.1021/jo701816h] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Amos B. Smith
- Department of Chemistry, The Penn Center for Molecular Discovery, and Monell Chemical Senses Center, University of Pennsylvania, Philadelphia, Pennsylvania 19104, and Cancer Research Institute, Arizona State University, Tempe, Arizona 85287
| | - Thomas M. Razler
- Department of Chemistry, The Penn Center for Molecular Discovery, and Monell Chemical Senses Center, University of Pennsylvania, Philadelphia, Pennsylvania 19104, and Cancer Research Institute, Arizona State University, Tempe, Arizona 85287
| | - Regina M. Meis
- Department of Chemistry, The Penn Center for Molecular Discovery, and Monell Chemical Senses Center, University of Pennsylvania, Philadelphia, Pennsylvania 19104, and Cancer Research Institute, Arizona State University, Tempe, Arizona 85287
| | - George R. Pettit
- Department of Chemistry, The Penn Center for Molecular Discovery, and Monell Chemical Senses Center, University of Pennsylvania, Philadelphia, Pennsylvania 19104, and Cancer Research Institute, Arizona State University, Tempe, Arizona 85287
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21
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Kumar SP, Nagaiah K. Stereoselective synthesis of the C31–C39 unit of (+)-phorboxazoles from m-anisaldehyde. Tetrahedron Lett 2007. [DOI: 10.1016/j.tetlet.2006.12.105] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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22
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Erpenbeck D, van Soest RWM. Status and perspective of sponge chemosystematics. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2007; 9:2-19. [PMID: 16817029 DOI: 10.1007/s10126-005-6109-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2005] [Accepted: 03/30/2006] [Indexed: 05/10/2023]
Abstract
In addition to their pharmaceutical applications, sponges are an important source of compounds that are used to elucidate classification patterns and phylogenetic relationships. Here we present a review and outlook on chemosystematics in sponges in seven sections: Secondary metabolites in sponges; Further applications of bioactive compound research in sponges; Sponge chemotaxonomy; Pitfalls of sponge chemotaxonomy; The chemotaxonomic suitability of sponge compounds; Potential synapomorphic markers in sponges; and The future of sponge chemotaxonomy.
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Affiliation(s)
- Dirk Erpenbeck
- Zoological Museum, IBED, University of Amsterdam, 1090GT Amsterdam, The Netherlands.
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23
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White JD, Kuntiyong P, Lee TH. Total Synthesis of Phorboxazole A. 1. Preparation of Four Subunits. Org Lett 2006; 8:6039-42. [PMID: 17165924 DOI: 10.1021/ol062530r] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[Structure: see text] Four subunits of the potent antitumor agent phorboxazole A were constructed; fragments C20-C32 and C9-C19 containing tetrahydropyrans A and B, respectively, were assembled using palladium-catalyzed intramolecular alkoxycarbonylation.
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Affiliation(s)
- James D White
- Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, USA.
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24
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Reiter M, Turner H, Gouverneur V. Intramolecular Hetero-Michael Addition of β-Hydroxyenones for the Preparation of Highly Substituted Tetrahydropyranones. Chemistry 2006; 12:7190-203. [PMID: 16819725 DOI: 10.1002/chem.200600415] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Structurally diverse beta-hydroxyenones are shown to undergo nonoxidative 6-endo-trig ring closure to form highly substituted tetrahydropyranones. Amberlyst-15, Al(ClO(4))(3) x 9 H(2)O and [Pd(MeCN)(4)](BF(4))(2) were found to be suitable catalysts for these intramolecular conjugate additions, preventing side reactions, such as dehydration or retroaldolisation. The use of [Pd(MeCN)(4)](BF(4))(2) is particularly effective, as this palladium-mediated reaction is under kinetic control and generates tri- and tetrasubstituted tetrahydropyranones with high levels of diastereocontrol. In the presence of the Lewis acid Al(ClO(4))(3) x 9 H(2)O, the reaction proceeded with a similar level of diastereocontrol; however, in contrast to [Pd(MeCN)(4)](BF(4))(2), this catalyst can promote enolisation. The palladium-mediated reaction was also found to be compatible with an enantioenriched beta-hydroxyenone substrate, giving no loss of enantiopurity upon ring closure. The most distinctive synthetic development to emerge from this new chemistry is the possibility to access tri- and tetrasubstituted 2,6-anti-tetrahydropyranones from anti-aldol precursors. These compounds are particularly difficult to access by using alternative methodologies. Two modes of activation were envisaged for the ring closure, involving metal coordination to either the C=C or C=O functional groups. Experimental results suggest that C=O coordination was the preferred mode of activation for reactions performed in the presence of Al(ClO(4))(3) x 9 H(2)O or [Pd(MeCN)(4)](BF(4))(2).
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Affiliation(s)
- Maud Reiter
- University of Oxford, Chemistry Research Laboratory 12, Mansfield Road, Oxford OX1 3TA, UK
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25
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Clarke PA, Santos S. Strategies for the Formation of Tetrahydropyran Rings in the Synthesis of Natural Products. European J Org Chem 2006. [DOI: 10.1002/ejoc.200500964] [Citation(s) in RCA: 280] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Paul A. Clarke
- School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
- Address from January 1, 2006: Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK
| | - Soraia Santos
- School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
- Address from January 1, 2006: Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK
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26
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Kataoka K, Ode Y, Matsumoto M, Nokami J. Convenient synthesis of highly optically active 2,3,4,6-tetrasubstituted tetrahydropyrans via Prins cyclization reaction (PCR) of optically active homoallylic alcohols with aldehydes. Tetrahedron 2006. [DOI: 10.1016/j.tet.2005.12.054] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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27
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Li DR, Zhang DH, Sun CY, Zhang JW, Yang L, Chen J, Liu B, Su C, Zhou WS, Lin GQ. Total Synthesis of Phorboxazole B. Chemistry 2006; 12:1185-204. [PMID: 16267861 DOI: 10.1002/chem.200500892] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
An efficient and highly convergent total synthesis of the potent antitumor agent phorboxazole B has been achieved. The synthetic strategy of this synthesis features: 1) a highly efficient substrate-controlled hydrogenation to construct the functionalized cis-tetrahydropyrane unit; 2) iterative crotyl addition to synthesize the segment that contains alternating hydroxyl and methyl substituents; 3) Hg(OAc)2/I2-induced cyclization to establish the cis-tetrahydropyrane moiety; 4) 1,3-asymmetric induction in the Mukaiyama aldol reaction to afford the stereogenic centers at C9 and C3; and 5) the exploration of the Still-Gennari olefination reaction to complete the macrolide ring of phorboxazoloe B.
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Affiliation(s)
- De-Run Li
- Shanghai Institute of Organic Chemistry, 354 Fenglin Rd, Shanghai 200032, PR China
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28
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Abstract
The C1-C17 bis-oxane subunit 22 of phorboxazole B is efficiently synthesized by exploiting differential reactivities between similar substituents on the hydropyran rings in 4. Selective dihydroxylation of the equatorial vinyl group, hydroboration of the axial vinyl group, and intramolecular Mitsunobu lactonization serve to fully differentiate the similar hydropyrans.
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Affiliation(s)
- Brian S Lucas
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706-1396, USA
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29
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Smith AB, Razler TM, Ciavarri JP, Hirose T, Ishikawa T. (+)-Phorboxazole A Synthetic Studies. A Highly Convergent, Second Generation Total Synthesis of (+)-Phorboxazole A. Org Lett 2005; 7:4399-402. [PMID: 16178543 DOI: 10.1021/ol051584i] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[structure: see text] A second generation total synthesis of the potent antitumor agent (+)-phorboxazole A (1) has been achieved. The cornerstone of this approach comprises a more convergent strategy, involving late-stage Stille union of a fully elaborated C(1-28) macrocycle with a C(29-46) side chain. The second generation synthesis entails the longest linear sequence of 24 steps, with an overall yield of 4.2%.
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Affiliation(s)
- Amos B Smith
- Department of Chemistry, Monell Chemical Senses Center, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
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30
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Lucas BS, Luther LM, Burke SD. A Catalytic Enantioselective Hetero Diels−Alder Approach to the C20−C32 Segment of the Phorboxazoles. J Org Chem 2005; 70:3757-60. [PMID: 15845024 DOI: 10.1021/jo050034v] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[reaction: see text] An efficient synthesis of the C20-C32 segment of the phorboxazoles has been achieved using an enantioselective hetero Diels-Alder reaction catalyzed by Jacobsen's Cr(III) amino indanol Schiff base catalyst.
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Affiliation(s)
- Brian S Lucas
- Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, Wisconsin 53706-1396, USA
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31
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Lowe JT, Panek JS. Stereocontrolled [4+2]-Annulation Accessing Dihydropyrans: Synthesis of the C1a-C10 Fragment of Kendomycin. Org Lett 2005; 7:1529-32. [PMID: 15816744 DOI: 10.1021/ol0501875] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[reaction: see text] Development of new organosilane reagents bearing C-centered chirality where the stereocenter is fully substituted, and their use in the stereocontrolled synthesis of cis- and trans-dihydropyrans containing a trisubstituted olefin is described. The reagents participate in Lewis acid promoted [4+2]-annulations providing useful levels of selectivity with both aliphatic and aromatic aldehydes. A stereoselective synthesis of the C1a-C10 fragment of kendomycin (1) is also described.
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Affiliation(s)
- Jason T Lowe
- Department of Chemistry and Center for Chemical Methodology and Library Development, Metcalf Center for Science and Engineering, 590 Commonwealth Avenue, Boston University, Boston, Massachusetts 02215, USA
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32
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Abstract
Novel and structurally diverse natural products containing imidazol-, oxazole-, or thiazole-unit(s) display a wide variety of biological activities. The isolation, biological activity and total synthesis of naturally occurring muscarine, imidazole, oxazole and thiazole alkaloids have been reviewed. The literature covers from January 2003 to June 2004.
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Affiliation(s)
- Zhong Jin
- Institute and State Key Laboratory of Elemento-organic Chemistry, Nankai University, Tianjin, 300071, PR China.
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33
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Abstract
An overview of marine natural products synthesis during 2003 is provided. The emphasis on total syntheses of molecules of contemporary interest, new total syntheses, and syntheses that have resulted in structure conformation or stereochemical assignments.
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Li DR, Sun CY, Su C, Lin GQ, Zhou WS. Toward the Total Synthesis of Phorboxazole B: An Efficient Synthesis of the C20−C46 Segment. Org Lett 2004; 6:4261-4. [PMID: 15524458 DOI: 10.1021/ol048275x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An efficient synthesis of the C20-C46 segment of phorboxazole B is described. The key steps involved Hg(OAc)(2)/I(2)-induced cyclization to construct the cis-tetrahydropyran moiety, the coupling of the metalated 2-methyloxazole 7 with lactone 6, and Julia olefination to furnish the conjugated diene moiety.
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Affiliation(s)
- De Run Li
- Shanghai Institute of Organic Chemistry, 354 Fenglin Rd, Shanghai 200032, P.R. China
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36
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Taylor MS, Jacobsen EN. Asymmetric catalysis in complex target synthesis. Proc Natl Acad Sci U S A 2004; 101:5368-73. [PMID: 15020767 PMCID: PMC397387 DOI: 10.1073/pnas.0307893101] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2003] [Indexed: 11/18/2022] Open
Abstract
This article describes three distinct strategies by which stereochemically complex molecules are synthesized and the ways asymmetric catalysis can impact on all three. The development of general methods to prepare synthetically useful building blocks leads to an expanded "chiral pool" of potential starting materials for asymmetric synthesis. The possibility of discovering new reactions to access new types of building blocks is particularly attractive and serves to help define the frontiers of the field. Asymmetric catalysis can also be applied to diastereoselective synthesis such that the stereochemistry of the catalyst, and not that of the substrate, determines the relative configuration of the product. Finally, in reactions where multiple stereocenters are generated simultaneously or in tandem, catalyst and substrate control can operate in a complementary manner to achieve one of many possible stereochemical outcomes selectively.
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Affiliation(s)
- Mark S Taylor
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
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Paterson I, Steven A, Luckhurst CA. Phorboxazole B synthetic studies: construction of C(1–32) and C(33–46) subtargets. Org Biomol Chem 2004; 2:3026-38. [PMID: 15480468 DOI: 10.1039/b407240e] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The convergent syntheses of the C(1-32) and C(33-46) domains of phorboxazole B are described. An iterative cyclocondensation strategy exploited the Jacobsen hetero-Diels-Alder (HDA) reaction as a platform for the synthesis of both the C(5-9) and C(11-15) tetrahydropyran rings. The use of 2-silyloxydiene coupling partners bearing an increasing resemblance to the phorboxazole skeleton was found to lead to a reduction in diastereoselectivity, however, in the case of the C(11-15) ring. The coupling of aldehyde and 2-silyloxydiene by this route provided a C(1-32) fragment which was elaborated to the macrolide core of phorboxazole B. The synthesis of the C(33-46) domain involved a Nozaki-Kishi coupling of aldehyde 31 and vinyl iodide 39. The syntheses of 31 and 39 were highly diastereoselective: an Evans [Cu(Ph-pybox)](SbF6)2-catalysed Mukaiyama aldol reaction formed the cornerstone of the synthesis of 31 whilst a Nagao-Fujita acetate aldol reaction provided a convenient means of installing the sole stereogenic centre of 39.
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Affiliation(s)
- Ian Paterson
- University Chemical Laboratory, Lensfield Road, Cambridge, UKCB2 1EW.
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Greeves N, Lee WM, McLachlan SP, Oakes GH, Purdie M, Bickley JF. Short synthesis of a tetrasubstituted tetrahydropyran with five stereogenic centres—stereoselective double tandem rearrangements and cyclisation. Tetrahedron Lett 2003. [DOI: 10.1016/j.tetlet.2003.09.209] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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39
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Run Li D, Qiang Tu Y, Lin GQ, Zhou WS. Studies on the synthesis of phorboxazole B: stereoselective synthesis of the C28–C46 segment. Tetrahedron Lett 2003. [DOI: 10.1016/j.tetlet.2003.09.141] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Chakraborty TK, Reddy V, Reddy T. Synthesis of highly substituted tetrahydropyrans: preparation of the C20–C28 moiety of phorboxazoles. Tetrahedron 2003. [DOI: 10.1016/j.tet.2003.08.056] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Lucas BS, Burke SD. Palladium(0)-Mediated Desymmetrization of Meso Tetraols: An Approach to the C3−C17 Bis-oxane Segment of Phorboxazoles A and B. Org Lett 2003; 5:3915-8. [PMID: 14535742 DOI: 10.1021/ol0354775] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[reaction: see text] meso-Tetraol bis(allylic acetates) 2 and 5 were synthesized via two-directional chain elongation. A palladium-mediated, ligand-controlled desymmetrization provided the desired bis-oxanes in greater than 98% ee. Bis-oxanes 1 and 4 represent potential synthetic intermediates for the C3-C17 subunits of phorboxazoles A and B.
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Affiliation(s)
- Brian S Lucas
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706-1396, USA
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Pattenden G, González MA, Little PB, Millan DS, Plowright AT, Tornos JA, Ye T. Total synthesis of (+)-phorboxazole A, a potent cytostatic agent from the sponge Phorbas sp. Org Biomol Chem 2003; 1:4173-208. [PMID: 14685321 DOI: 10.1039/b308305e] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A convergent total synthesis of phorboxazole A (1a), from the C(3-19), C(20-27) and C(33-46) fragments 5, 4 and 91, respectively, concentrating on stereocontrolled formation of the bonds at C(2-3), C(19-20) and C(27-28), is described. Although a coupling reaction between a macrolide ketone and the side chain substituted sulfone, at C(27-28) was not successful, a Wadsworth-Emmons olefination involving the oxane methyl ketone 4 and an oxazole produced the oxane 90 which was next coupled to 91 leading to the C(20-46) unit 100. A further coupling of 100 to 71c at C(19-20) then led to 105, ultimately, and the synthesis was completed by a macrocyclisation reaction from 105, at the C(2-3) alkene bond, followed by deprotection of 106.
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Affiliation(s)
- Gerald Pattenden
- School of Chemistry, The University of Nottingham, University Park, Nottingham, UK NG7 2RD.
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