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Kaneko M, Yamashita A, Yasuno Y, Yamauchi K, Sakai K, Oishi T. Synthesis of the MN Ring of Caribbean Ciguatoxin C-CTX-1 via Desymmetrization by Acetal Formation. Org Lett 2024; 26:855-859. [PMID: 38241474 DOI: 10.1021/acs.orglett.3c04013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2024]
Abstract
The MN ring of Caribbean ciguatoxin C-CTX-1 was synthesized from a meso-syn-2,7-dimethyloxepane derivative corresponding to the M ring via desymmetrization by acetal formation with a camphor derivative, followed by construction of the N ring via the Horner-Wadsworth-Emmons reaction and acetal formation. The meso-syn-2,7-dimethyloxepane derivative was synthesized via photoinduced electrocyclization of a conjugated exo-diene under flow conditions, giving a cyclobutene derivative, followed by ring expansion via oxidative cleavage and diastereoselective reduction of a β-hydroxy ketone.
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Affiliation(s)
- Masahiro Kaneko
- Department of Chemistry, Faculty and Graduate School of Science, Kyushu University, 744 Moooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Atsuhiro Yamashita
- Department of Chemistry, Faculty and Graduate School of Science, Kyushu University, 744 Moooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Yoko Yasuno
- Department of Chemistry, Faculty and Graduate School of Science, Kyushu University, 744 Moooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Kosei Yamauchi
- Department of Chemistry, Faculty and Graduate School of Science, Kyushu University, 744 Moooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Ken Sakai
- Department of Chemistry, Faculty and Graduate School of Science, Kyushu University, 744 Moooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Tohru Oishi
- Department of Chemistry, Faculty and Graduate School of Science, Kyushu University, 744 Moooka, Nishi-ku, Fukuoka 819-0395, Japan
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Triantafyllakis M, Alexander S, Woolford S, Wilson C, Clark JS. Synthesis of the A-F Fragment of the Pacific Ciguatoxin CTX3C by Iterative Ring-Closing Metathesis and Tsuji-Trost Allylation. Chemistry 2023; 29:e202303121. [PMID: 37830907 PMCID: PMC10946863 DOI: 10.1002/chem.202303121] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 10/12/2023] [Accepted: 10/13/2023] [Indexed: 10/14/2023]
Abstract
The fully functionalized A-F fragment of the Pacific ciguatoxin CTX3C has been synthesized from a derivative of D-glucal, which serves as the B-ring. Rings A and C were introduced to either side of ring B by ring-closing diene and enyne metathesis (RCM). The seven-membered D-ring and eight-membered E-ring were assembled by iterative use of a six-step reaction sequence in which RCM was used for ring construction and Tsuji-Trost allylation was employed for subsequent stereoselective functionalization. The nine-membered F-ring was formed by use of an RCM reaction and bears the functionality required for attachment of the I-M fragment and subsequent closure of rings G and H.
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Affiliation(s)
- Myron Triantafyllakis
- School of ChemistryJoseph Black BuildingUniversity of GlasgowUniversity AvenueGlasgowG12 8QQUK
| | - Sam Alexander
- School of ChemistryJoseph Black BuildingUniversity of GlasgowUniversity AvenueGlasgowG12 8QQUK
| | - Sophie Woolford
- School of ChemistryJoseph Black BuildingUniversity of GlasgowUniversity AvenueGlasgowG12 8QQUK
| | - Claire Wilson
- School of ChemistryJoseph Black BuildingUniversity of GlasgowUniversity AvenueGlasgowG12 8QQUK
| | - J. Stephen Clark
- School of ChemistryJoseph Black BuildingUniversity of GlasgowUniversity AvenueGlasgowG12 8QQUK
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