This begins a partial listing of the abstracts of papers tentatively scheduled to be presented at the 9th International Congress of Essential Oils. The balance of the abstracts will be published in our report issue of April/May Perfumer & Flavorist.
Unique tricyclic eudesmenones transformed from santanolide, S. Inayama, H. Hori, A. K. Singh, T. Kawamata, T. Shibata, Keio University, and Y. Iitaka, Tokyo University, Japan
A fragrant tricyclic eudesmenone (1) and its inodorous ring isomers (2) were obtained together with tetracyclic adamantanone (3) by an unusual reaction of 3-deoxyhexahydro-l-α-santonin with hot phosphoryl chloride. The structure, conformation and absolute configuration of 1, 2a and b and 3 were all established by spectroscopic especially CD/RD determinations and X-ray diffractions of 1 and 3 as well as 10α, 11α-epoxides of 2a and 2b. The proposed reaction pathway for this unique cyclization-skeletal rearrangement from the eudesmanolide to 3 through 1 and/or 2a, b was rationalized by heat of formation based on a semiempirical MO calculation.