Eudesmane 3-Eudesmol

Epoxy-cis-eudesmane (300), the defence pheromone of the West African termite, has been synthesized from lO-epi-y-eudesmol (299) by means of an... 

Nine eudesmane derived sesquiterpenes were isolated from Aristolochia species. Among them, a- and P- eudesmols (325), (326), a-, P- and 8- selmenes (319), (322), (321) and selina-3,7(ll)-diene (320) were found in the essential oils of various Aristolochia members. Govindachari et al. [334] isolated aristolochene (324), a sesquiterpene... 

Given the relatively rare occurrence of eremophilanes in Eremophila species, it is perhaps of little surprise that compounds displaying the putative precursor skeleton, eudesmane, have also been rarely observed. P-Eudesmol (71) has been isolated or detected in a number of species, sometimes co-occurring with elemol (72) (14,15,67). 

Another approach to the eudesmane skeleton has recently been described by Carlson and Zey which also does not depend upon a Robinson annelation reaction (Scheme 25). By this sequence the keto-ester (252) was obtained as the predominant isomer. Previously this compound has been converted into / -eudesmol (cf. ref 142). 

Three agaroflirans (85-87) and P-eudesmol (88) were isolated from the petroleum ether-soluble fraction of the methanolic extract of the fresh rhizomes of A. japonica [63]. It is biogenetically interesting that P-eudesmol was present in the same plant with agaroflirans which possess a 10-epieudesmol skeleton. From the rhizomes of A. japonica, three eudesmane-type sesquiterpenes, 10-ep/-5P-hydroperoxy-p-eudesmol (89), 10-e /-5a-hydroperoxy-P-eudesmol (90) and 4,10-e/ /-5P-hydroxydihydroeudesmol (91) were isolated and their structure were determined by spectroscopic methods and chemical conversions [64]. Compounds 89-91 are considered to be biosynthesized from lO-ep/ -y-eudesmol (92), which was a possible precursor of agarofuran-type... 

Well-known eudesmane derivatives in flavors and fragrances include a- and p-selinene from the oils of Cannabis saliva var. indica (Moraceae), celery (Apium graeveolens, Umbelliferae) and hops (Humulus lupulus, Moraceae), (+)-a- and (+)-P-eudesmol from some oils of eucalyptus (Eucalyplus macarlhuri), (-)-epi-y-eudesmol with its woody odor from the north African oil of geranium (Pelargonium odoralissimum and allied species), and the almost odorless diastereomeric (+)-y-eudesmol from various ethereal oils (+)-p-Costus acid and (+)-p-costol belong to the constituents of the essential oil obtained from the roots of Saussurea... 

The methodology was extended to provide synthetic routes to the sesquiterpenes eudesmane (209), a-selinene (212a), and a-eudesmol (212b) [43,68] (Scheme 6.68). The intermediate diene (208) was found to be a single isomer, presumed to have ( )-geometry. 

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