Ambergris odor

Availability until recently, there was no known way to obtain, at any cost, the natural odor concentrates of muguet, lilac, gardenia and a great deal of other flowers we do not know how to raise the whale population that would be needed to satisfy our demand for ambergris odor. 

Okoumal 126, a powerful ambergris odorant, has two stereogenic centers in the 1,3-dioxolane ring and therefore there are four stereoisomers of 126a-d. The four stereoisomers of disila-okoumal 125 were obtained by chromatographic separation of the racemate prepared by Scheme 24. 

C16H28O, Mr 236.40, nip 75-76 °C, is a crystalline autoxidation product of ambrein (see Ambergris, p. 184) with a typical ambergris odor. It is prepared from (-)-sclar-eol, a diterpene alcohol obtained from extraction of clary sage plants (see Sage Oils,... 

CompositionMain components are linalyl acetate (see linalool) (45-70%) and linalool (10-20%). Depending on the distillation conditions it also contains small amounts (up to a few %) of the diterpene alcohol (-)-sclareol (see labdanes). These components constitute the main part (ca. 70%) of the solvent extract of clary ( clary concrete ). Larger areas in USA, Israel, and parts of the fcnina USSR are used for the cultivation of C. to produce sclareol. (-)-Sclareol is the starting material for the valuable ambergris odor substance (- )-8,12-epoxy-13,14,15,16-tetranorlab-dane ( ambroxide , ambrox , CisHjjO, Mr 236.40) The tricyclic lactone (+)-norambreinolide ( sclare-olide , C,6H2 02, Mr 250.38) is usually an intermediate.. 0... 

Jeger s ketal (394), named after its discoverer, but also called Amberketal, Ambrake-tal, and Ketamber, is another material with a powerful ambergris odor. It is prepared from manool (395), extracted from the New Zealand tree Dacrydium biforme, by permanganate oxidation to the ketone (396) followed by osmylation of the double bond and spontaneous formation of the ketal from the resultant diol-ketone. It has also been synthesized from larixol (397), which is readily available from the European larch, Larix decidua 449). 

Asymmetric acetylation of ( )-y-cyclohomogeraniol (24) with vinyl acetate and lipase AK gave (K)-Y-cyclohomogeranyl acetate (25) and (S)-Y-cyclohomogeraniol (24) (Figure 24.13) [15,16]. These were converted to ancistrodial (a defense substance of a termite) and y-coronal (an ambergris odorant), respectively. 

Ohloff, G., Schulte-Eke, K.H., and Muller, B.L. (1977) Formation of ambergris odorants from ambrein imder simulated natural conditions. Helv. Chim. Acta, 60, 2763—2766. 

In the above-mentioned works, 3 was converted to 21 (Fig. 12), which served as the key intermediate in the syntheses. For the preparation of an isomeric alcohol 22, its racemate was acetylated with vinyl acetate in the presence of lipase AK (Amano) to give the acetate (i )-23 and the remaining alcohol (5)-22 [48]. The enantiomers of 22 served as the intermediate for the synthesis of ancistrodial, a defense substance of a termite Ancistrotermes cavithorax [49], (5)-7-coronal, an ambergris odorant [48], and the enantiomer of the antibacterial terpene from Premna oligotricha [49]. 

Acetyl cedrene (95) is obtained by the acetylation of the hydrocarbon fraction, a-cedrene [469-61-4] (91). The product has a woody, warm-ambergris, and musk odor, and many types of products are available (189). 

The odor of ambergris, urine, sandalwood, and musk are believed to be related to their distinct structures, and small structural modifications can influence decisively the odor quality and potency. There are three different classes of musk that are not related in structure ... 

C13H22O, Mr 194.32, 20 0.940-0.960, n 1.485-1.498, is a colorless to pale yellow liquid with an extremely powerful, amber, somewhat musty and animal odor. It is a constituent of ambergris (see p. 174). A synthesis starts with the thermolysis of /3-ionone (see p. 63) which leads to dehydroambrinol. The title compound is obtained by hydrogenation over Raney nickel in methanolic solution [115]. 

Fresh ambergris is almost black, but it turns light gray and develops a pleasant odor when exposed to light and seawater over a period of time. The major components of ambergris are epicoprosterol and the odorless triterpene alcohol, ambrein [473-03-0]. 

Together, these compounds largely represent the odor of ambergris. Ambergris is applied as a 3% tincture in 90% ethanol, which is matured by standing over a period of time with occasional shaking. It was used in fine fragrances. FCT 1976 (14) p. 675. 

Cypress oil is produced by steam distillation of terminal branches of Cupressus sempervirens L. (Cupressaceae). It is a liquid with a wood-like odor that has an ambergris note. 

Cistus and labdanum products come from Mediterranean countries, mainly Spain, where the Cistus shrub grows abundantly. They are used widely in perfumery, giving perfume compositions a warm, balsamic tonality with a touch of ambergris. The typical odor originates from a number of compounds which are formed by oxidative degradation of diterpenes with labdane skeleton, which are the main constituents of labdanum gum [284a, 558 565aj. The resinoids and absolutes are excellent natural fixatives. FCT 1976 (14) p.335 [8016-26-0], [89997-74-0]. 

Maleczka, R. E. Paquette, L. A. Adaptation of oxyanionic sigmatropy to the convergent enan-tioselective synthesis of ambergris-type odorants J. Org. Chem. 1991, 56, 6538-6546. 

However, there are also many synthetic materials, and materials of plant origin, that resemble natural animal odors such as musk and ambergris without having the intense fecal or urinous overtones that require them to be hidden within a composition at a level where their presence cannot be consciously recognized. These materials may be quite different chemically to the natural product, but to us their odor and effect are similar. Included in this category are the amber notes derived from labdanum and clary sage, as well as the numerous synthetic musk materials such as galaxolide and musk ketone. 

Labdanum Oil occurs as a golden yellow, viscous liquid with a powerful, balsamic odor, which on dilution, is reminiscent of ambergris. It turns dark brown on standing. It is the volatile oil obtained by steam distillation from crude labdanum gum extracted from the perennial shrub Cistus ladaniferus L. (Fam. 

Ohloff G, Vial C, Wolf HR, Job K, Jegou E, Polonsky J, Lederer E.. Stereochemistry—odor relationships in enantiomeric ambergris fragrances. Helv. Chim. Acta. 1980 63 1932-1946. 

CH3(CH2)8CH(CH3)CHO, Ci2H240, Mr 184.32, bPl3 114 °C, d 5 0.830, ng1 1.4321, is reported as being found in nature. It is a colorless liquid, with an odor markedly different from that of the isomeric dodecanal. It has a fatty odor with incense and ambergris notes. 

C15H30O2, Mr 242.40, is not known in nature. It is a colorless liquid, bpo.i pa 94 °C, df5 0.931, ng° 1.463-1.467, with a noble woody odor with ambergris nuances. It is prepared by reaction of cyclododecanol with paraformaldehyde/hydrochloric gas to give cyclododecyl chloromethyl ether, which is treated with sodium ethylate [116]. 

Cyclic ethers used as fragrances include a number of terpenoid compounds. Some of them, such as 1,4-cineole [470-67-7] and 1,8-cineole, occur in essential oils in significant quantities. Others are only minor components examples are rose oxide, ner-ol oxide [1786-08-9], and rose furan [15186-51-3], which contribute to the specific fragrance of rose oil. Caryophyllene oxide [1139-30-6], which has a woody, slightly ambergris-like odor, can be prepared by treatment of -caryophyllene with organic peracids. a-Cedrene oxide [11000-57-0] is another wood-fragrance compound, which can be easily prepared by epoxidation of cedarwood oil hydrocarbons. 

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