Sesquiterpene isolongifolene

An investigation has been made of the stereochemistry of epoxidation of the sesquiterpene isolongifolene. The a-epoxide structure 29 has been proved by x-ray crystallography. 

Farnum, Mehta, and co-workers have shown that longifolene 218 and isolongifolene 219 in HSO3F media give a mixture of cyclohexenyl cations at different temperatures. Quenching these cations provides some unusual sesquiterpene like Cis-hexahydronaphthalenes 220-225 (Scheme 5.82). 

Santhanakrishnan, T. S., U. R. Nayak, and Sukh Dev Studies in Sesquiterpenes. XLII. Isolongifolene (Part 3) Systematic Degradation. Tetrahedron 26, 641 (1970). 

Mehta, G., D. N. Dhar, and S. C. Suri Addition of Chlorosulphonyl Isocyanate to Some Polycyclic Sesquiterpenes, Longifolene, Isolongifolene, a-Cedrene, Caryo-phyllene and Thujopsene. Indian. J. Chem. 16B, 87 (1978). 

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