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Wu CP, Devendar B, Su HC, Chang YH, Ku CK. Efficient synthesis and applications of 2-substituted azulene derivatives: towards highly functionalized carbo- and heterocyclic molecules. Tetrahedron Lett 2012. [DOI: 10.1016/j.tetlet.2012.07.040] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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2
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Pepper HP, Kuan KKW, George JH. Synthesis of a Liphagal–Frondosin C Hybrid and Speculation on the Biosynthesis of the Frondosins. Org Lett 2012; 14:1524-7. [DOI: 10.1021/ol300257v] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Henry P. Pepper
- School of Chemistry & Physics, University of Adelaide, North Terrace, Adelaide SA 5005, Australia
| | - Kevin K. W. Kuan
- School of Chemistry & Physics, University of Adelaide, North Terrace, Adelaide SA 5005, Australia
| | - Jonathan H. George
- School of Chemistry & Physics, University of Adelaide, North Terrace, Adelaide SA 5005, Australia
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3
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Lee DW, Pandey RK, Lindeman S, Donaldson WA. Reactivity of acyclic (pentadienyl)iron(1+) cations: Synthetic studies directed toward the frondosins. Org Biomol Chem 2011; 9:7742-7. [DOI: 10.1039/c1ob05720k] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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4
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Ovaska TV. Synthesis of cycloheptanoid natural products via tandem 5-exo cyclization/Claisen rearrangement process. ARKIVOC 2010; 2011:34-44. [PMID: 22514791 PMCID: PMC3327132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023] Open
Abstract
This article describes the development of microwave-assisted oxyanionic 5-exo-dig cyclization-Claisen rearrangement sequence as a convenient "one-pot" route to a variety of seven-membered carbocyclic ring systems. This process was used as the key transformation for the construction of several natural products, including frondosins A, B, and C.
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Affiliation(s)
- Timo V Ovaska
- Department of Chemistry, Connecticut College, 270 Mohegan Avenue, New London, CT 06320,
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Basavaiah D, Aravindu K, Kumar KS, Reddy KR. Simple, One-Pot, and Facile Synthesis of Angularly Fused [6-7-5], [6-7-6], [6-7-7], and [6,7] Ring Systems Using Baylis-Hillman Acetates. European J Org Chem 2010. [DOI: 10.1002/ejoc.200901483] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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6
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Masters KS, Flynn BL. An efficient synthesis of (±)-frondosin B using a Stille–Heck reaction sequence. Org Biomol Chem 2010; 8:1290-2. [DOI: 10.1039/b924542a] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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7
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Ovaska TV, Sullivan JA, Ovaska SI, Winegrad JB, Fair JD. Asymmetric synthesis of seven-membered carbocyclic rings via a sequential oxyanionic 5-exo-dig cyclization/claisen rearrangement process. Total synthesis of (-)-frondosin B. Org Lett 2009; 11:2715-8. [PMID: 19514798 DOI: 10.1021/ol900967j] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Appropriately substituted nonracemic allyl alcohols, readily prepared from the corresponding enones by application of the CBS methodology, were converted to optically active cycloheptenone derivatives with almost complete transfer of chirality via an efficient "one-pot", cycloisomerization/Claisen rearrangement process. This methodology was directly applied to the expedient total synthesis of (-)-frondosin B.
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Affiliation(s)
- Timo V Ovaska
- Department of Chemistry, Connecticut College, 270 Mohegan Avenue, New London, Connecticut 06320, USA.
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Masters KS, Flynn BL. A concise approach to the polycyclic scaffold of frondosin D. J Org Chem 2008; 73:8081-4. [PMID: 18798675 DOI: 10.1021/jo800682n] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In a study directed at developing a concise approach to the polycyclic core of frondosin D, a Stille-Heck sequence has been identified that gives direct access to the trimethylbicyclo[5.4.0]undecane ring system common to all frondosins.
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Affiliation(s)
- Kye-Simeon Masters
- Department of Medicinal Chemistry, Victorian College of Pharmacy, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
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10
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Simmons E, Hardin A, Guo X, Sarpong R. Rapid Construction of the Cortistatin Pentacyclic Core. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200802203] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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11
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Simmons E, Hardin A, Guo X, Sarpong R. Rapid Construction of the Cortistatin Pentacyclic Core. Angew Chem Int Ed Engl 2008; 47:6650-3. [DOI: 10.1002/anie.200802203] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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12
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Li X, Keon AE, Sullivan JA, Ovaska TV. Studies toward frondosin A and its analogues. Formal total synthesis of (+/-)-frondosin A. Org Lett 2008; 10:3287-90. [PMID: 18611033 DOI: 10.1021/ol8011343] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Two reaction sequences commencing with different starting materials were successfully employed for the synthesis of frondosin A analogues, including (+/-)-frondosin A dimethyl ether. Construction of the bicyclo[5.4.0]undecane core in each case was achieved through an expedient microwave-assisted tandem 5-exo cyclization--Claisen rearrangement process.
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Affiliation(s)
- Xin Li
- Department of Chemistry, Connecticut College, 270 Mohegan Avenue, New London, Connecticut 06320, USA
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13
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Olson JP, Davies HML. Asymmetric [4 + 3] Cycloadditions between Benzofuranyldiazoacetates and Dienes: Formal Synthesis of (+)-Frondosin B. Org Lett 2008; 10:573-6. [DOI: 10.1021/ol702844g] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jeremy P. Olson
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260-3000
| | - Huw M. L. Davies
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260-3000
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Ovaska TV, Kyne RE. Intramolecular thermal allenyne [2 + 2] cycloadditions; facile construction of the 5-6-4 ring core of sterpurene. Tetrahedron Lett 2008; 49:376-378. [PMID: 19562093 DOI: 10.1016/j.tetlet.2007.11.042] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
A variety of 1-allenyl-2-propargyl-substituted cyclopentanol derivatives were found to undergo facile intramolecular microwave-assisted 2+2 alleneyne cycloaddition reactions to generate tricyclic 5-6-4 ring systems present in the sterpurenes.
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Affiliation(s)
- Timo V Ovaska
- Department of Chemistry, Connecticut College, 270 Mohegan Avenue, New London, CT 06320, USA
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Cho EJ, Lee D. Total synthesis of (3R,9R,10R)-panaxytriol via tandem metathesis and metallotropic [1,3]-shift as a key step. Org Lett 2007; 10:257-9. [PMID: 18076184 DOI: 10.1021/ol702651s] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Enyne metathesis is unique for its capacity to carry out multiple bond formation in tandem fashion. Its combined use with metallotropic [1,3]-shift allowed for the development of a novel strategy for the total synthesis of a conjugated 1,3-diyne-containing natural product (3R,9R,10R)-panaxytriol.
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Affiliation(s)
- Eun Jin Cho
- Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, Chicago, Illinois 60607, USA
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Memarian H, Saffar-Teluri A. Microwave-assisted and light-induced catalytic ring opening of α-epoxyketones using DDQ. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/j.molcata.2007.05.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Trost BM, Hu Y, Horne DB. Total synthesis of (+)-frondosin A. Application of the Ru-catalyzed [5+2] cycloaddition. J Am Chem Soc 2007; 129:11781-90. [PMID: 17760442 DOI: 10.1021/ja073272b] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The first total synthesis of (+)-frondosin A was accomplished in 19 longest linear and 21 total steps from commercially available materials. The key features of the synthesis include a Ru-catalyzed [5+2] cycloaddition, a Claisen rearrangement, and a ring expansion to construct the core of the frondosin A in a diastereoselective and regioselective fashion. This is the first application of a Ru-catalyzed [5+2] cycloaddition in the total synthesis of a natural product. Through this synthesis, the absolute configuration of (+)-frondosin A was established.
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Affiliation(s)
- Barry M Trost
- Department of Chemistry, Stanford University, Stanford, California 94305-5080, USA.
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Abstract
An expeditious reaction sequence featuring a microwave-assisted tandem 5-exo cyclization-Claisen rearrangement process was used to assemble the A/B ring system of frondosin B. Completion of the target natural product was achieved in 38.2% yield over an eight-step linear sequence.
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Affiliation(s)
- Xin Li
- Department of Chemistry, Connecticut College, 270 Mohegan Avenue, New London, Connecticut 06320, USA
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Li X, Kyne RE, Ovaska TV. Synthesis of seven-membered carbocyclic rings via a microwave-assisted tandem oxyanionic 5-exo dig cyclization-claisen rearrangement process. J Org Chem 2007; 72:6624-7. [PMID: 17655366 PMCID: PMC2523263 DOI: 10.1021/jo0710432] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Appropriately substituted 1-alkenyl-4-pentyn-1-ol systems, readily prepared from simple starting materials, serve as useful precursors to a number of substituted cyclohept-4-enone derivatives via a microwave-assisted tandem oxyanionic 5-exo cyclization/Claisen rearrangement sequence. The reactions involving terminally substituted 4-pentyn-1-ols were found to be highly stereoselective, with the alpha and beta groups in the final product showing a strong preference for the trans orientation.
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Affiliation(s)
- Xin Li
- Department of Chemistry, Connecticut College, 270 Mohegan Avenue, New London, Connecticut 06320, USA
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Total syntheses of (±)-frondosin C and (±)-8-epi-frondosin C via a tandem anionic 5-exo dig cyclization–Claisen rearrangement sequence. Tetrahedron 2007. [DOI: 10.1016/j.tet.2006.12.057] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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