1. The author thanks Dr H.P. Benecke, for the1H-NMR, Dr R.H. Bailey for the MS and Miss Patricia Cofer for the collection of the plant material. Thanks are also due to Prof. R.A. Abramovitch, for a generous supply of chemicals and his interest. The use of the facilities of this Department is also gratefully acknowledged.
2. J. Bhattacharyya and D.H. Miles, Tetrahedron Lett,1977, 2749.
3. D.H. Miles, J. Bhattacharyya, N.V. Mody, J.L. Atwood, S. Black, and P.A. Hedin, J. Am. chem. Soc.99, 618 (1977).
4. Satisfactory C, H analyses were obtained for the new compounds.
5. A.D. Cross, H. Carpio and P. Crabbe, J. chem. Soc.1963, 5539.