1. A. Groweiss, S.A. Look and W. Fenical, J. Org. Chem., 53, 2401, (1988); D.J. Faulkner, Nat. Prod. Rep., 10, 497, (1993) and references therein.

2. Taken from the Ph.D. thesis of M.B.R., University of Salford, 1993.

3. F. Leyendecker and M.-T. Comte, Tetrahedron, 42, 1413, (1986).

4. R.Bergamaseo, D.H.S. Horn, R.H. Nearn, and J.S. Wilkie, Aust. J. Chem., 38, 475, (1985).

5. For a thorough discussion, see Y. Yamamoto, Y. Chounan, S. Nishii, T. Ibuka, and H. Kitahara, J. Am. Chem. Soc., 114, 7652, (1992), and references cited therein.

6. S.S. Wong and M.N. Paddon-Row, J. Chem. Soc., Chem. Commun., 456, (1990) and references cited therein.

7. E.J. Corey and R.K. Bakski, Tetrahedron Lett., 31, 611, (1990).

8. H.C. Brown, J. Chandrasekharan and P.V. Ramachandran, J. Am. Chem. Soc., 110, 1539, (1988).

9. W.H. Pirkle, D.L. Sikhenya and M.S. Paulin, J. Org. Chem., 42, 384, (1977); W.H. Pirkle and C.W.Boeder, J. Org. Chem., 42, 3697,(1977).