1154
5. (a) Larson, D. P.; Heathcock, C. H. J. Org. Chem. 1996, 61, 5208–5209. (b) Lu, S.-F.; O’yang, Q.; Guo, Z.-W.; Yu, B.; Hui,
Y.-Z. Angew. Chem., Int. Ed. Engl. 1997, 36, 2344–2346.
6. Leather, G. R. Weed Sci. 1983, 31, 37–42.
7. (a) Macías, F. A.; Varela, R. M.; Torres, A.; Molinillo, J. M. G.; Fronczek, F. R. Tetrahedron Lett. 1993, 34, 1999–2002.
(b) Macías, F. A.; Molinillo, J. M. G.; Varela, R. M.; Torres, A.; Fronczek, F. R. J. Org. Chem. 1994, 59, 8261–8266. (c)
Macías, F. A.; Varela, R. M.; Torres, A.; Molinillo, J. M. G. Tetrahedron Lett. 1999, 40, 4725–4728.
8. Heliannuol A (1) has been synthesized, see: Grimm, E. L.; Levac, S.; Trimble, L. A. Tetrahedron Lett. 1994, 35, 6847–6850.
9. During the preparation of this manuscript, a reported synthesis of heliannuol A and D came to our attention, see: Takabatake,
K.; Sato, K.; Kakehashi, T.; Nishi, I.; Shindo, M.; Shishido, K. Chem. Abs. 1999, 131, 73489 and 144720.
10. Carreño, M. C.; García Ruano, J. L.; Sanz, G.; Toledo, M. A.; Urbano, A. J. Org. Chem. 1995, 60, 5328.
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14. Joseph-Nathan, P.; Tovar-Miranda, R.; Martínez, E.; Santillan, R. L. J. Nat. Prod. 1988, 51, 1116.
15. This somewhat disappointing yield for the coupling and reduction sequence is in stark contrast to similar coupling reactions
of aryl zinc species with the same vinyl triflate that proceed in 85–90% yield for the 2 step sequence: Looper, R. E. M. S.
Thesis, Western Washington University: Bellingham, WA, 1999.
16. For 10: δH10=2.79, app t, J=6.2 Hz; for 11: δH10=2.83, dd, J=9 and 3 Hz; The stereochemical assignment was confirmed
by X-ray diffraction of a model 2-(5-methyl-2H,3H,4H,5H-benzo[f]oxepan-2-yl)propan-2-ol. Details of the stereochemical
correlation will be reported in the full article describing this work.
17. For some relevant phenol–epoxide cyclizations, see: (a) Arnone, A.; Bernardi, R.; Bravo, P.; Frigerio, M.; Ticozzi, C. Gazz.
Chim. Ital. 1989, 119, 87–94 and references cited therein. (b) Krohn, K.; Baltus, W. Tetrahedron 1988, 44, 49–54. (c)
Weerawarna, S. A.; Guha-Biswas, M.; Nelson, W. L. J. Heterocycl. Chem 1991, 28, 1395–1403.
18. (a) Feutrill, G. I.; Mirrington, R. N. Tetrahedron Lett. 1970, 1327–1328. (b) Feutrill, G. I.; Mirrington, R. N. Aust. J. Chem.
1972, 25, 1719–1729.
19. The melting point of our synthetic 4 is 162–163°C, 100 degrees higher than was reported for the natural material in the
original work (Ref 7b). Professor Macías confirmed via personal communication that an error exists in the original paper,
and that the melting point of natural heliannuol D is 159–161°C.