Linalyl Derivatives

4 Linalyl Derivatives.- The new linalyl derivatives (97) and (98) have been isolated from yudzu (Citrus junos) peel. A number of hydroxylated linalools (99) - (102) have been found in the Vitls 

Cinnamomum camphora, and its total synthesis has been reported. 

A comparative study on the incorporation of H-labelled neryl, geranyl, and linalyl derivatives into a-terpineol by cell-free 

Linalyl acetate (106) reacts with thexylborane to give the cyclic 

Treatment of this with sodium cyanide followed by trifluoroacetic 

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Figure 3. Linalyl derivatives cyclize preferentially from the anti-endo conformation.

Aroma chemicals are isolates, or chemically treated oils or components of oils. Some components are removed physically, others chemically. In most cases, they are further purified by distillation. For example, Bois de Rose (rosewood) oil may be distilled to isolate linalool, which may be then further treated chemically to yield derivatives such as linalyl acetate, an important fragrance ingredient and a primary component in its own right of lavender and lavandin oils. Vetiver oil Haiti, although containing only 70% alcohols, is treated with acetic anhydride, then carefully distilled to include valuable odor components in the distillate, even though they may not be esters. 

Methyl salicylate 144 (Structure 4.44), the main constituent of wintergreen oil, is derived from benzoic acid. Other important esters are linalyl acetate 145, benzyl benzoate 146 and benzyl isobutyrate 147. 

Ethyl acetate, which is a comparatively small molecule, has the typical fruity character associated with all the lower esters, and a more or less equal balance between the influence of the two structural units, derived from ethyl alcohol and acetic acid. Linalyl acetate and geranyl acetate, however, although retaining the typical character of an acetate have much less of the ester fruitiness and are more closely related to the corresponding alcohols, linalool, and geraniol. The dominance of the alcohol appears to be even greater in phenylethyl acetate and paracresyl acetate (a phenolic ester). 

Although a variety of primary and secondary amines can be utilized as nitrogen nucleophiles, amina-tion of allylic substrates with ammonia has been reported to be unsuccessful. Therefore, bis(p-methoxy-phenyDmethylamine, sodium p-toluenesulfonamide or sodium azide have been utilized instead of ammonia. In the presence of a palladium catalyst, imides, such as phthalimide, react with allylic esters with the exception of geranyl and linalyl acetates. 0-Geranyl- and 0-linalyl-isourea derivatives, however, reacted with phthalimide giving the expected -allylic phthalimides in 65% and 71% yields, respectively. ... 

Triol (21) was prepared according to Williams et al. (7J using diastereoisomeric 6,7-epoxy-linalyl acetate. In our hands, (21) was directly amenable to HRGC Rt 2427. Derivatization afforded the a-cetonide derivatives with Rt s 1828 and 1837,respectively (the natural (21) co-chromatographed with the isomer at Rt 1828). Synthesis of (24) and (25) was accomplished by Se02 oxidation of linalool (13) and afforded, after reductive work-up, the (E)- and (Z)-isomers in a ratio of about 10 1. Spectral properties ( H-NMR, MS, FTIR) corresponded to those published (13,14,15). HRGC Rj. s 2294 and 2254. 

Composition Genuine essential oils consist exclusively of volatile components with boiling points mainly between 150 and 300 °C. They contain predominantly hydrocarbons or monofunctional compounds such as aldehydes, alcohols, esters, ethers, and ketones. Parent compounds are mono- and sesquiterpenes, phenylpropane derivatives, and longer-chain aliphatic compounds. Accordingly, essential oils are relative non-polar mixtures, i.e., they are soluble in most organic solvents. Often the organoleptic properties are not determined by the main components but by minor and trace compounds such as, e.g., 1,3,5-undecatrienes and pyrazines in galbanum oil. In many of the commercially important oils, the number of identified components exceeds 100. Very many of the constituents are chiral, frequently one isomer predominates or is exclusively present, e. g., (- )-menthol in peppermint oils or (-)-linalyl acetate in lavender oil. 

Geranyl and Neryl Derivatives.- Geranyl- and linalyl-3-D-glucosides have been detected in shoots of Camellia sinensis, ... 

The reactions are late steps in the biosynthetic pathway. Thymol, for instance, is formed from y-terpinene via p-cymene, camphor from bornyl pyrophosphate via borneol (Fig. 100). Menthol is derived from piperitenone as shown in Fig. 101. Terpinyl acetate and linalyl acetate are esters of with acetic acid, respectively. 

V.2.5.1 ELIMINATION OF ALLYLPALLADIUM AND RELATED DERIVATIVES 1985 TABLE 2. Elimination Reactions of Geranyl Acetate, Neryl Acetate, and Linalyl Acetate... 

Thomas, A. F., and R. Dubini Terpenoids Derived from Linalyl Oxide. 3. The Isolation, Structure, Absolute Configuration and Synthesis of the Davanafurans, Nor-Sesquiterpenes Isolated from Artemisia pallens. Helv. Chim. Acta 57, 2006 (1974). 

Terpenoids Derived from Linalyl Oxide. 4. The Oxidation of Davanone. Isola-... 

Several typical examples of naturally occurring fragrant compounds, that is, synthesized by plants and flowers and other living organisms, are shown in Fig. 12.1. Geraniol-nerol and citronellol (and their derivatives) are responsible for the rosy floral scents. Linalool causes the floral scent of lavender and bergamot. Linalyl acetate gives fruity odor. Methyl ionone is found in iris-violet. Menthol may be familiar to you the odor of mint comes from it. Pine scent is caused by terpineol, bomeol, and their derivatives. 

Umney and Bennett have examined a Chinese nerolioil derived from Citrus triptera. It had a specific gravity 0-850 and optical rotation + 35 . It contained 4-8 per cent, of esters calculated aslinalyl acetate, and 21 per cent, of free alcohols as linalol. It contained much limonene, camphene, linalyl acetate, methyl-anthranUate and a paraffin. 

The more complicated cyclic carbon skeletons of the bornanes, thujanes and pinanes are also derived from intramolecular cyclization of the linalyl cation. Members of all three families are present in the essential oil of cotrrmon sage (Salvia officinalis) which contains some 75 separate volatile compounds (Santos-Gomes and Fernandes-Ferreira... 

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