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DOI: 10.1039/A903063H (Paper) Reference Section for: Chem. Commun., 1999, 1063-1064

Convergent synthesis of the ABCDE ring framework of ciguatoxin

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Kenji Maeda, Tohru Oishi, Hiroki Oguri and Masahiro Hirama

Abstract

An alkylation–metathesis sequence is shown to be a powerful method to synthesize the ABCDE ring framework of ciguatoxin 1.

References

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  11. The stereochemistry of 2 was unambiguously determined by 1H NMR analysis. Selected data for 2: δH(500 MHz, CDCl3) 0.98 (9H, s, TBDPS), 0.99 (9H, s, TBDPS), 1.55 (1H, q, J 11.4, H14ax), 1.53–1.60 (1H, m, H22), 1.62–1.69 (1H, m, H22′), 1.71–1.78 (1H, m, H21), 2.05–2.14 (1H, m, H21′), 2.29 (1H, dt, J 11.4, 4.1, H14eq), 2.31-2.38 (1H, m, H8), 2.64 (1H, ddd, J 16.0, 7.7, 3.5, H8′), 3.08–3.15 (2H, m, H12, H13), 3.28(0)(1H, ddd, J 8.4, 7.7, 3.8, H9), 3.28(5)(1H, ddd, J 11.4, 8.9, 4.1, H15), 3.31–3.40 (2H, m, H20, H24), 3.35 (1H, dd, J 9.0, 8.4, H10), 3.48 (1H, t, J 9.0, H11), 3.62–3.70 (3H, m, H23, H25, H25′), 3.88 (1H, dq, J 8.9, 2.3, H16), 4.01 (1H, dq, J 16.0, 2.8, H5), 4.12 (1H, dq, J 9.0, 2.3, H19), 4.29 (1H, dd, J 16.0, 5.7, H5′), 4.83 (1H, d, J 11.5, CH2Ph), 4.89 (1H, d, J 11.5, CH2Ph), 5.64 (1H, dt, J 13.0, 2.3, H18), 5.77 (1H, dddd, J 11.8, 5.1, 3.5, 2.8, H7), 5.83 (1H, dt, J 13.0, 2.3, H17), 5.87 (1H, ddt, J 11.8, 5.7, 2.8, H6), 7.23–7.43 (17H, m, Ph), 7.52–7.56 (4H, m, Ph), 7.59–7.66 (4H, m, Ph).
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