Farnesol ambrette seed

Farnesol, CjsH gO, is an aliphatic sesquiterpene alcohol, which occurs in ambrette seed oil, and flower oils of the type of acacia, lime flowers, mignonette, and lilac flowers. 

Other components are acyclic aliphatic esters and terpenes, such as farnesol and farnesyl acetate [237-239a]. Ambrette seed oil is one of the most expensive essential oils and, thus, is used mainly in fine fragrances and in alcoholic beverages. FCT 1975 (13) p.705 [8015-62-1], [84455-19-6]. 

Of the four possible isomers (due to the double bonds in the 2- and 6-positions), the trans-trans isomer is the most common in nature and occurs, for example, in ambrette seed oil. 2-c/s-6-rra s-Farnesol has been identified in petitgrain oil Biga-rade. 

All four isomers of farnesol (111) are found in nature and all have odors in the muguet and linden direction. The commonest is the ( , )-isomer that occurs in, among others, cabreuva and ambrette seed, while the (Z, )-isomer has been found in jasmine and ylangylang, the ( , -isomer in cabreuva, rose, and neroli, and the (Z,Z)-isomer in rose. Nerolidol (113) is the allylic isomer of farnesol and exists in four isomeric forms two enantiomers each of two geometric isomers. 

The reference study of the composition of the odiferous components of ambrette seed was by Maurer and Grieder [30]. A review of ambrette analysis is published [31]. The extract obtained from the freshly broken seeds by L.CO2 is a viscous but mobile oil containing all of the 7-hexadecen-16-olide, 5-tetradecen-14-olide, farnesol and acetates of famesols, 5-dodecenol and 5-tetradecenol. About 60% of this oil is not steam volatile and composed of the stable lipids outlined earlier in this chapter. 

Sesquiterpenic alcohols Examples of sesquiterpenic alicyclic alcohols (8-24) are farnesol and nerolidol (also known as peruviol). Both alcohols, smelling of flowers, are components of many essential oils used in perfumery. Of the four possible geometric isomers, the (2 ,6B)-isomer of farnesol, is the most common in nature and occurs, for example, in basil oil and ambrette (Abelmoschus moschatus Malvaceae) seed oil. The (2Z,6 )-isomer occurs in the petit grain oil bigarade, which is derived from the bitter orange tree leaves (Citrus aurantiumvai. amara, Rutaceae). Farnesol is a natural pesticide for mites and a pheromone for several species of insects. Nerolidol with a double bond at C-6 occurs in the form of (Z)- and ( )-isomers, each of which can exist as an enantiomeric pair (chiral carbon C-3). The individual enantiomers and their mixtures are found in many essential oils. For example, the essential oil known as cabreuva oil that is used in perfumery is obtained from the bark of the South American tree Myrocarpus frondosus (Fabaceae) and contains the (-F)-(E)-isomer of nerolidol (3S,6 )-nerolidol. 

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