1. Brown, K. S., and Djerassi, C. (1964)J. Am. Chem. Soc. 86, 2451?2463.
2. Cordell, G. A., Saxton, J. E., Shamma, M., Smith, G. F. (1989)Dictionary of Alkaloids, Vol. 2 (Chapman and Hall, New York) pp. 441?444.
3. Harper, J. K., Li, D., Wood, S. G., Mayne, C. L., Cates, R. G., and Owen, N. L. (1993) Manuscript in preparation.
4. Kahrl, J., Gebreyesus, T., and Djerassi, C. (1971)Tetrahedron Lett.,27, 2527?2529.
5. Kirsi, J. J., McKernan, P. A., Burns, N. J., North, J. A., Murray, B. K., and Robins, R. K. (1984)Antimicrob. Agents Chemother.26, 466?475.