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. 2012 Nov 16;14(22):5748-51.
doi: 10.1021/ol302751b. Epub 2012 Oct 26.

Synthesis of the C1-C26 hexacyclic subunit of pectenotoxin 2

Ozora Kubo  1 , Daniel P Canterbury, Glenn C Micalizio
Affiliations

Synthesis of the C1-C26 hexacyclic subunit of pectenotoxin 2

Ozora Kubo et al. Org Lett. .

Abstract

Synthesis of the C1-C26 hexacyclic subunit of pectenotoxin-2 (PTX-2) is described that features a stereoselective annulation to generate the C-ring by triple asymmetric Nozaki-Hiyama-Kishi coupling followed by oxidative cyclization. Preparation of the C1-C14 AB spriroketal-containing subunit employs a recently developed metallacycle-mediated reductive cross-coupling between a TMS-alkyne and a terminal alkene.

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Figures

Figure 1
Figure 1
Introduction. A. Structure of PTX2 B. Convergent assembly of the C1-C26 subunit of PTX2. C. C-ring annulation via asymmetric Nozaki-Hiyama-Kishi coupling/epoxidation/cyclization.
Scheme 1
Scheme 1
C-ring annulation strategy and synthesis of 8. A. Proposed annulation of the PTX2 C-ring: B. Synthesis of vinyliodide 5:
Scheme 2
Scheme 2
NHK-based annulation for 2,2,5-trisubstituted THFs.
Scheme 3
Scheme 3
Synthesis of a CDEF-containing subunit of PTX2.
Scheme 4
Scheme 4
Synthesis of the AB spiroketal-containing subunit 3.
Scheme 5
Scheme 5
NHK coupling between 3 and 4, and attempted epoxidation/cyclization cascade.
Scheme 6
Scheme 6
Closure of the C-ring via iodoetherification.
See this image and copyright information in PMC

References

    1. Chae H, Choi T, Kim B, Jung J, Bang Y, Shin DY. Oncogene. 2005;24:4813–4819. - PubMed
    1. Jung JH, Sim CJ, Lee C. J Nat Prod. 1995;58:1722–1726. - PubMed
    1. Spector I, Braet F, Shochet nR, Bubb MR. Micro Res And Tech. 1999;47:18–37. - PubMed
    1. Yasumoto T, Murate M, Oshima Y, Sano M, Matsumoto GK, Clardy J. Tetrahedron. 1985;41:1019–1025.
    2. Sasaki K, Wright JLC, Yasumoto T. J Org Chem. 1998;63:2475–2480. - PubMed
    3. Yasumoto T, Murata M. Chem Rev. 1993;93:1897–1909.
    1. Yasumoto T, Oshima Y, Sugawara W, Fukuyo Y, Oguri H, Igarashi T, Fujita N. Bull Jpn Soc Sci Fish. 1980;46:1405–1411.
    2. Lee J, Igarashi T, Fraga S, Dahl E, Hovgaard P, Yasumoto T. J Appl Phycol. 1989;1:147–152.
    3. Draisci R, Lucentini L, Giannetti L, Boria P, Poletti R. Toxicon. 1996;34:923–935. - PubMed

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