Musk

The original musk components of perfumes were extracted from animal sources. Nowadays, such sources are obsolete on both ethical and economical grounds. The two major ones were musk and civet, which were 

The natural musks were always very expensive and their macrocyclic structures presented synthetic challenges, which were not conquered, even on laboratory scale, until the pioneering work of Ruzika (1926). It was therefore of major importance to the fragrance industry when, in 1888, Baur discovered the nitromusks. He had actually been working on explosives and noticed that the product of t-butylation of trinitrotoluene (TNT) had a pleasant, sweet, musky odour. The compound was named Musk Baur, although the alternative name, Musk Toluene, eventually became more common. For a while it was also known as Tonkinol, because of the similarity of its odour to that of musk Tonkin. Baur then searched for analogues of this material and discovered Musk Xylene, 

The nitromusks became the main contributors of musk notes in perfumery and maintained that position until the middle of the twentieth century. However, nitromusks suffer from a number of disadvantages and the discovery of the polycyclic musks in the middle of the twentieth 

Cumene is prepared on a large scale from benzene and propylene as an intermediate in the synthesis of acetone and phenol. This makes it an inexpensive and readily available starting material for the production of Galaxolide. Three further electrophilic addition reactions complete the synthesis. First, /.voamylene is added to form pentamethylindane to 

Many methods have been developed in an attempt to overcome the problem posed by entropy in the formation of large rings. Inclusion of unsaturation in the substrate reduces the number of degrees of freedom in it and consequently increases the possibility of the two ends of the chain meeting. In the acyloin reaction, electrostatic attraction is used to restrict movement of the alkyl chain. A dicarboxylic acid is added to a suspension of sodium (or another alkali metal) particles in an inert solvent. The acid functions react with the metal to form carboxylate anions, which are then held to the positive surface of the metal by electrostatic attraction. This means that the chain becomes a loop, fastened to the metal particle at each end until the two carboxylate groups approach close enough to allow the acyloin reaction to take place between them. 

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CifiHjoO. A yellow liquid b.p. 330°C. The perfume base obtained from the scent glands of the Tibetan musk deer also available by synthesis. 

Trinitro-3-tert-butyltoluene, m.p. 97°C, yellow crystals. Used in perfumery and known as musk hour. 

Musk ketone is 4-ter/-butyl-2,6-dimethyl-3,5-dinitroacetophenone, yellow crystals, m.p. 135-136°C. 

Revision Problem 4 Musks are compounds which have some pleasant smell themselves, but function chiefly by retaining and enhancing the perfume of other compounds. How might celestoHde , a modem musk, (TM 398) be made ... 

Ambrettohde is obtained from hibiscus and has a musk like odor Its preparation from a compound A is outlined in the table that follows Write structural formulas ignonng stereochem istry for compounds B through G in this synthesis Hint Zinc as used in step 4 converts vici nal dibromides to alkenes )... 

Musk fragrances Musk odor Musk Oil Muskol MuskTibetine [145-39-1] Muslin Mussels Mustard... 

Synthetic lubricants Synthetic marble Synthetic membranes Synthetic methanol Synthetic musk Synthetic natural gas... 

Wigglers Wijs reagent Wij s solution Wild cherry Wild Musk Wiley melting point... 

Whatever the physiology of odor perception may be, the sense of smell is keener than that of taste (22). If flavors are classed into odors and tastes as is common practice in science, it can be calculated that there are probably more than 10 possible sensations of odor and only a few, perhaps five, sensations of taste (13,21,35—37). Just as a hereditary or genetic factor may cause taste variations between individuals toward phenylthiourea, a similar factor may be in operation with odor. The odor of the steroid androsterone, found in many foods and human sweat, may eflcit different responses from different individuals. Some are very sensitive to it and find it unpleasant. To others, who are less sensitive to it, it has a musk or sandalwood-like smell. Approximately 50% of the adults tested cannot detect any odor even at extremely high concentrations. It is befleved that this abiUty is genetically determined (38). 

Other commonly occurring chemical groups ia essential oils iaclude aromatics such as P-phenethyl alcohol, eugenol, vanillin, ben2aldehyde, cinnamaldehyde, etc heterocycHcs such as iadole (qv), pyra2iaes, thia2oles, etc hydrocarbons (Liaear, branched, saturated, or unsaturated) oxygenated compounds such as alcohols, acids, aldehydes, ketones, ethers and macrocyclic compounds such as the macrocyclic musks, which can be both saturated and unsaturated. 

Since muscone (101), by itself, does not reproduce the total odor impression of this musk, IFF chemists (56) as early as 1971 in an analysis of tincture of Tonquin musk, reported a series of macrocycHc ketones (Table 16) which play a key role in creating the characteristic odor of this musk (11). The introduction of a double bond into a macrocycHc ketone (eg, 102) changes the odor from flowery musk to animal musk. 

P-methjlcyclotridecanone [61415-11-0] strong floral musk with an animal character... 

B. D. Mookherjee and R. W. TrenMe, "Volatile Constituents of Tiacture of Tonquia Musk," paper presented at the FTIIth International Congress of Essential Oils, Oct. 12—17, 1980, Cannes, Grasse, France. 

Orienta.lFa.mily. In these perfumes, a mossy, woody, and spicy accord combines with the sweetness of vanilla or balsam and is accented with animal notes such as amber, civet, and musk. The most important floral accords used are rose and jasmine. 

Musk Family. Even though the musk trend began as a counterculture fashion, these accords have become widely accepted. 

Musk Family. Musk notes, combined with previously accepted accords, have made this a popular group. 

Old Spice Musk for Men (Shulton 1974) Royal Copenhagen Musk (Swank 1975)... 

In addition to large-scale process work, there is also some effort expended in providing synthetic methods for producing small amounts (<100 kg/yr) of materials needed for replacement of naturals that are being discontinued or in short supply. Examples are ambrinol (59) and dihydro-y-ionone (60) for the replacement of ambergris. More recendy, tincture of tonquin musk has been replaced by using, among other materials, mixtures of macrocyclic ketones and alcohols which have been found in the natural substance. 

Hemimellitene. In addition to some specialized solvent appHcations, hemimellitene can be converted to musk Tibetine [145-39-17, 1-/gf/-butyl-3,4,5trimethyl-2,6-dinitrobenzene (14) via 5-/ l -butyl-l,2,3-trimethylbenzene [98-23-7] (13). 

Another significant use of 3-methylphenol is in the production of herbicides and insecticides. 2-/ f2 -Butyl-5-methylphenol is converted to the dinitro acetate derivative, 2-/ f2 -butyl-5-methyl-4,6-dinitrophenyl acetate [2487-01 -6] which is used as both a pre- and postemergent herbicide to control broad leaf weeds (42). Carbamate derivatives of 3-methylphenol based compounds are used as insecticides. The condensation of 3-methylphenol with formaldehyde yields a curable phenoHc resin. Since 3-methylphenol is trifunctional with respect to its reaction with formaldehyde, it is possible to form a thermosetting resin by the reaction of a prepolymer with paraformaldehyde or other suitable formaldehyde sources. 3-Methylphenol is also used in the production of fragrances and flavors. It is reduced with hydrogen under nickel catalysis and the corresponding esters are used as synthetic musk (see Table 3). 

Benzyl saUcylate can be prepared by the reaction of ben2yl chloride with an alkaU salt of saUcyhc acid at 130—140°C or by the transesterification of methyl saUcylate with benzyl alcohol. It is used as a fixative and solvent for nitro musks and as a fragrance for detergents. Benzyl saUcylate was priced at... 

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). 

In some cases, especially when the family is directed more toward Oriental fragrances, the use of vanillin can be up to 5%. These types of perfumes include Spanish fougnre, sweet or fmity chypres, woody Oriental, or spicy Oriental notes. AH the perfumes based on the sweet, warm, and powdery impressions brought by vanillin belong to the great family of the Oriental notes and of the amber notes. Vanillin, when used together with coumarin and nitro-musks, can have a concentration of up to 10%. 

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