Perfumes cedarwood derivatives

Ced rwood. Many varieties of cedarwood oil are obtained from different parts of the world. They are produced mainly by steam distillation of chipped heartwood, but some are also produced by solvent extraction. The oils, which vary significantly ia chemical composition, are used ia perfumes as such, but the main uses are as distillation fractions and chemical derivatives. For the latter purposes the most used oils, which are similar ia composition, are from Texas ia the United States (Juniperus mexicand) and from China Cupressusfunebris). The principal constituents of these oils are cedrene [11028-42-5] (4), thujopsene [470-40-6] (5), and cedrol [77-53-2] (6). The first two of these are obtained together by distillation and used mostiy ia the form of acetylated derivatives. Cedrol is used as such and, to a greater extent, as its acetate ester. 

Many natural products such as labdanum, cedarwood, and clary sage are fractionated and chemically treated (in this or in the reverse order) to produce derivatives of exceedingly complex composition which, for the perfumer s purposes, behave as naturals. These can be... 

The synthesis of Vertofix (acetyl cedrene) from cedarwood in the early 1960s marked a major step forward in perfumery chemistry, providing perfumers with a fine woody material at a reasonable price, which could be used not only to replace the very much more expensive vetiver derivatives but also had an excellent performance in many functional products such as soaps and shampoos. It is interesting also to find in Fidji a small amount of PTBCHA (Vertenex), another relatively new material at that time, and one more frequently associated with functional products. Here it acts as a link between the woody notes and the fresh green top note. 

The major components of the Cedrus wood oils are cedrol, cedrene and thujopsene, and a number of perfume ingredients are made from these. The most important is acetylated cedarwood. This product is used because it possesses a much stronger cedarwood odour than the natural oil and is available under various trade names such as Lixetone and Vertofix . The acetylation can be carried out using acetyl chloride in the presence of a Lewis acid or by using a Bronsted acid system such as polyphos-phoric acid/acetic anhydride or sulfuric acid/acetic anhydride. The cedrol dehydrates into cedrene under the reaction conditions and so the major component in the product is acetylcedrene. However, the main contributor to the odour of the complex reaction product mixture is the ketone derived from acetylation of thujopsene (Daniker et al., 1972). These reactions are shown in Figure 4.36. 

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