1. ibid;McMurry;ibid,1964
2. Synthesis unpublished work;Oppolzer;Am Chem Soc,1980
3. Thesis No Université de Genève Synthesis unpublished results in press;Godel;Chem Angew Chem Engi Chim Acta Chim Acta Chim Acta Tetrahedron Lett Chem Soc,1971
4. in press Syntheses of cyclic natural products de Methoden der Organischen Chemie Georg Thieme Verlag;Oppolzer;Chim Acta Chem Res,1980
5. Generous financial support of this work by the Swiss National Science Foundation Sandoz Ltd Givaudan Vernier is gratefully acknowledged REFERENCES;Basel;Chem Angew Chem mt Chern Angew Chem Engl Chem Rev,1976