✦ LIBER ✦
Thermal rearrangement of bicyclogermacrane-1,8-dione. Synthesis of humulenedione and (−)-cubenol, starting from natural (+)-Aromadendrene-V
✍ Scribed by Harrie J.M. Gijsen; Joannes B.P.A. Wijnberg; Aede de Groot
- Book ID
- 104203083
- Publisher
- Elsevier Science
- Year
- 1994
- Tongue
- French
- Weight
- 800 KB
- Volume
- 50
- Category
- Article
- ISSN
- 0040-4020
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✦ Synopsis
Treatment of a distillation tail of Eucalyptus globulus, containing mainly (+)-aromadendrene (1) and (-)-alloaromadendrene (Z), with K/Al203 gives a quantitative conversion of 1 anti 2 into isoledene (4). Oxidative cleavage of the central double bond in 4 produces (+)-bicyclogermacrane-l,Sdione (5). Thermal rearrangement of 5 gives via a homo [1,5J hydrogen shift at relatively low
temperature the humulenedione 6, and at higher temperature (FVPJ the products 9 and 10 both with a cadinane skeleton. The naturally occurring humulenedione ( 7) and I-)-cubenol ( 17) can be synthesized starting from 6 and 9, respectively.