J. R. Gone et al. / Tetrahedron Letters 50 (2009) 1023–1025
1025
6. (a) Sanchez-Viesca, F.; Romo, J. Tetrahedron 1963, 19, 1285–1291; (b) Bohlman,
F.; Bornowaki, H.; Arndt, C. Chem. Ber. 1966, 99, 2828–2834.
2.32–2.49 (m, 2H), 2.86–2.96 and 3.10–3.20 and 3.28–3.43 (m, 2H total), 4.06–
4.19 and 4.32–4.39 (2 ꢁ m, 1H total), 5.24–5.50 (m, 2H), 5.81–5.92 (m, 1H),
7.35–7.49 (m, 6H), 7.65–7.76 (m, 4H).
7. For reviews of guianolide/pseudoguianolide syntheses see: (a) Heathcock, C. H..
In The Total Synthesis of Natural Products; ApSimon, J., Ed.; John Wiley & Sons:
New York, 1973; Vol. 2, pp 197–558; (b) Heathcock, C. H.; Graham, S. L.;
Pirrung, M. C.; Plavac, F.; White, C. T.. In The Total Synthesis of Natural Products;
ApSimon, J., Ed.; John Wiley & Sons: New York, 1983; Vol. 5, (c) Pirrng, M. C.;
Morehead, A. T., Jr.; Young, B. G.. In The Total Synthesis of Natural Products;
Goldsmith, D., Ed.; John Wiley & Sons: New York, 2000; Vol. 11.
14. A similar selective reduction has been reported: Davies, H. M. L.; Doan, B. D. J.
Org. Chem. 1998, 63, 657–660.
15. Compound 17: 1H NMR (400 MHz, CDCl3) d 0.71 (d, J = 7.2 Hz) and 0.92 (d,
J = 7.2 Hz) total 3H, 1.04 and 1.05 (2 ꢁ s, 9H total), 1.19–2.02 (m, 7H), 2.15–
2.44 (m, 5H), 2.49–2.65 and 3.01–3.08 (m, 1H total), 3.96–4.06 and 4.27–4.35
(m, 1H total), 5.25 (d, J = 2.4 Hz) and 5.35 (d, J = 1.6 Hz) 1H total, 7.34–7.48 (m,
6H), 7.62–7.74 (m, 4H); FAB-HRMS m/z 450.2793 (calcd for C29H37NOSiLi
(M+Li+) m/z 450.2804).
8. For a recent review on the synthesis of guianolides with a trans-lactone moiety
see: Schall, A.; Reiser, O. Eur. J. Org. Chem. 2008, 2353–2364.
9. Semi-syntheses of guianolides have been reported from photochemical
16. Repeated chromatography of the mixture of diastereomers lead to a small
sample greatly enriched in one diastereomer. The relative configuration of this
diastereomer was unassigned, and in general the mixture of diastereomers was
used in the synthesis. Compound 19: 1H NMR (400 MHz, CDCl3) d 1.06 (d,
J = 7.2 Hz, 3H), 1.44 (dt, J = 13.5, 8.0 Hz, 1H), 1.49–1.90 (m, 8H), 2.01 (dd,
J = 13.4, 9.8 Hz, 1H), 2.19 (br t, J = 8.0 Hz), 2.44–2.54 (m, 1H), 2.55–2.59 (m, 2H),
2.90 (d, J = 6.0 Hz, 1H), 4.39–4.48 (m, 1H); FAB-HRMS m/z 228.1586 (calcd for
C13H19NOSiLi (M+Li+) m/z 228.1576).
rearrangement the naturally occurring terpene
a-santonin: (a) Zhang, W.;
Luo, S.; Fang, F.; Chen, Q.; Hu, H.; Jia, X.; Zhai, H. J. Am. Chem. Soc. 2005, 127, 18–
19; (b) Barques, V.; Blay, G.; Cardona, L.; Garcia, B.; Pedro, J. R. J. Nat. Prod. 2002,
65, 1703–1706; (c) Yuuya, S.; Hagiwara, H.; Suzuki, T.; Ando, M.; Yamada, A.;
Suda, K.; Kataoka, T.; Naai, K. J. Nat. Prod. 1999, 62, 22–30; (d) Lauridsen, A.;
Cornett, C.; Vulpius, T.; Moldt, P.; Christensen, S. B. Acta Chem. Scand. 1996, 50,
150–157.
10. For earlier work see: (a) Wallock, N. J.; Donaldson, W. A. Org. Lett. 2005, 7,
2047–2049; (b) Wallock, N. J.; Bennett, D. W.; Siddiquee, T. A.; Haworth, D. T.;
Donaldson, W. A. Synthesis 2006, 3639–3646.
11. Yong, W.; Vandewalle, M. Synlett 1996, 911–912.
12. Gree, R.; Laabassi, M.; Moset, P.; Carrie, R. Tetrahedron Lett. 1985, 26, 2317–
2318.
17. Griffith, W. P.; Ley, S. V.; Marsden, S. P.; Norman, J. Synthesis 1994, 639–666.
18. Borrelly, S.; Paquette, L. A. J. Am. Chem. Soc. 1996, 118, 727–740.
19. The crystallographic data for 21 has been deposited with the CCDC (CCDC
Union Road, Cambridge CB12 1EZ, UK; fax: +44(1223)336033; e-mail:
13. Selected spectral data: 12: 1H NMR (300 MHz, CDCl3) d 0.45 (d, J = 9.0 Hz, 1H),
1.02 and 1.03 (2 ꢁ s, 9H total), 1.84 (d, J = 6.0 Hz, 3H), 2.03–2.34 (m, 4H), 3.25–
3.37 (m, 1H), 3.55–3.65 (m, 1H), 3.66 and 3.68 (2 ꢁ s, 3H total), 4.13–4.22 (m,
1H), 4.36–4.53 (m, 2H), 4.96–5.03 (m, 1H), 7.32–7.46 (m, 6H), 7.60–7.68 (m,
4H); FAB-HRMS m/z 607.1784 (calcd for C32H36O6SiFeLi (M+Li+) m/z 607.1791).
Compound 14: 1H NMR (300 MHz, CDCl3) d 0.81 (d, J = 9.0 Hz, 3H), 1.08 and 1.09
(2 ꢁ s, 9H total), 1.52–1.74 (m, 2H), 1.87–1.99 (m, 1H), 2.22–2.3.11 (m, 1H),
20. Compound 24: 1H NMR (300 MHz, CDCl3) d 0.89 (d, J = 7.8 Hz, 3H), 1.39–1.54
(m, 2H), 1.56–1.70 (m, 1H), 1.90–2.11 (m, 3H), 2.18–2.43 (m, 5H), 2.44–2.59
(m, 2H), 2.65 (dd, J = 7.2, 16.2 Hz, 1H), 4.07 (dd, J = 9.6, 9.6 Hz, 1H); 13C NMR
(75 MHz, CDCl3) d 20.3, 28.3, 30.1, 34.5, 37.5, 40.5, 40.7, 43.0, 44.1, 45.5, 86.6,
176.0, 217.7. FAB-HRMS m/z 223.1336 (calcd for C13H19O3 (M+H+) m/z
223.1334).