Myrcene turpentine

In several important cases, new synthetic strategies have been developed into new production schemes. An outstanding example of this is the production of an entire family of terpene derivatives from a-pinene (29), the major component of most turpentines, via linalool (3) (12). Many of these materials had been produced from P-pinene, a lesser component of turpentine, via pyrolysis to myrcene and further chemical processing. The newer method offers greater manufacturing dexibiUty and better economics, and is environmentally friendly in that catalytic air oxidation is used to introduce functionality. 

Uses ndReactions. Some of the principal uses for P-pinene are for manufacturing terpene resins and for thermal isomerization (pyrolysis) to myrcene. The resins are made by Lewis acid (usuaUy AlCl ) polymerization of P-pinene, either as a homopolymer or as a copolymer with other terpenes such as limonene. P-Pinene polymerizes much easier than a-pinene and the resins are usehil in pressure-sensitive adhesives, hot-melt adhesives and coatings, and elastomeric sealants. One of the first syntheses of a new fragrance chemical from turpentine sources used formaldehyde with P-pinene in a Prins reaction to produce the alcohol, Nopol (26) (59). 

Pinene is similar to a-pinene in its reactions. Pyrolytic cleavage to myrcene, the starting material for acyclic terpenes, is used on an industrial scale. Addition of formaldehyde results in the formation of nopol nopyl acetate is used as a fragrance material. /3-Pinene is produced in large quantities by distillation of turpentine oils. It is used as a fragrance material in household perfumery. However, most /3-pinene is used in the production of myrcene. 

The terpenes used were mainly /3-pinene fractions provided by DRT (Soci6td des Derives Rdsiniques et Terpeniques, Vielle-S Girons) and, for certain experiments a turpentine oil containing the main three terpenes a-pinene, /3-pinene, and A -carene. The /3-pinene fractions contained 80-90% /3-pinene, 2% a-pinene, 4-5% myrcene, 2-3% dipentene and 700-1500 ppm S. GC-MS analyses showed that sulfur impurities were composed of alkyl and alkenyl sulfides (mainly dimethyl sulfide), alkyl and alkenyl disulfides (mainly dimethyl disulfide), trisulfides, thiophene and alkylthiophenes (methyl, dimethyl, acetyl and tertiobutyl). 

Impregnation of cobalt and molybdenum (without sodium) increases largely the isomerizing activity of the catalyst the /3-pinene is then completely converted. The catalysts prepared with sodium molybdate and sodium hydroxide (Co-Mo-Na and Na-Co-Mo-Na) have lower isomerizing activities while their HDS activities are significantly increased. As in the case of alumina supported catalysts the sulfided CoMo phase protected by a double layer of alkaline ions on the carbon support gives the best results in HDS of /3-pinene. The behaviour of this catalyst was examined in desulfurization of the turpentine oil (40% a-pinene, 25% /3-pinene, 25% A -carene and 10% camphene + dipentene + myrcene, 1500 ppm S). The results are recorded in Table 6. 

In all examples of the palladium-catalyzed telomerization discussed up till now, the nucleophile (telogen) can be considered renewable. The taxogens used (butadiene, isoprene), however, are still obtained from petrochemical resources, although butadiene could, in principle, also be obtained from renewable resources via the Lebedev process that converts (bio)-ethanol into 1,3-butadiene. Limited attention has been given in this respect to the great family of terpenes, as they provide direct access to renewable dienes for telomerization. In particular, those terpenes industrially available, which are derived mostly from turpentine, form an attractive group of substrates. Behr et al. recently used the renewable 1,3-diene myrcene in the telomerization with diethylamine, for instance [18]. The monoterpene myrcene is easily obtained from (3-pinene, sourced from the crude resin of pines, by pyrolysis, and is currently already used in many different applications. 

Terpenes are obtained either by processing wood in the kraft process in paper production or by collecting resins and turpentine from conifers. The scale of produced terpenoids in comparison with fats and oils is small. Applications for terpenes are in pure form as solvents, as odorous substances, or in dyes. Most terpenoids contain double bonds which are readily available to perform chemical reactions. A widespread component of turpentine is a-pinene, from which many fragrances are produced. A further often-used resource is myrcene, which is obtained by pyrolysis of (3-pinene. Myrcene is an important base chemical to produce, for example, the fragrances nerol and geraniol [7]. 

Neral Limonene (lemons) Myrcene (bayberry) a-Pinene (turpentine)... 

Among these molecules, only a few have been the subject of extensive studies related to their polymerization, namely those which can be readily isolated in appreciable amounts from turpentine a-pinene, P-pinene, limonene and, to a lesser extent, myrcene [5]. 

Myrcene is a hydrocarbon which occurs in many essential oils such as those obtained from parsley leaf, rosemary, celery leaf, hops, lemon-grass, cardamom seeds and blackcurrant buds. It is also obtained when P-pinene, a major constituent of turpentine, is heated to a high temperature. It has a pleasant odour for a hydrocarbon, being described as sweet, balsamic, herbal and refreshing. 

Terpene tor- pen [ISV terp- (fir. Gr Terpen-tin turpentine, fir. ML terhentina) + -ene] (1873) n. A class of unsaturated organic compounds having the empirical formula C10H16 occurring in most essential oils and oleoresinous plants. Structurally, the unimportant terpenes and their derivatives are classified as monocyclic (dipentene), bicyclic (pinene), and acyclic (myrcene). 

Myosin see Muscle proteins Myrcene a triply unsaturated acyclic monoterpene hydrocarbon. M is a pleasant smelling liquid, M, 136.24, b.p.,2 55-56°C, p 0.8013, n 1.470. It is a component of many essential oils, and it is prepared for the perfumery industry by pyrolysis of p-pinene (from oil of turpentine). M. is al used commercially for the preparation of isomeric acyclic monoterpene alcohols and their acetates... 

Myrcene (70) is very widespread in nature. Some sources, such as hops, contain high levels and it is found in most of the common herbs and spices. All isomers of a-ocimene (84), b-ocimene (85), and alio ocimene (86) are found in essential oils, the isomers of b-ocimene (85) being the most frequently encountered. Limonene (73) is present in many essential oils, but the major occurrence is in the citrus oils that contain levels up to 90%. These oils contain the dextrorotatory (/ ) -enantiomer, and its antipode is much less common. Both a phellandrene (87) and b phellandrene (88) occur widely in essential oils. For example, ( ) a phellandrene is found in Eucalyptus dives and (5)-(-)-b-phellandrene in the lodge-pole pine, Pinus contorta. p Cymene (83) has been identi ed in many essential oils and plant extracts and thyme and oregano oils are particularly rich in it. a-Pinene (65), b-pinene (7, and 3-carene (77) are all major constituents of turpentine from a wide range of pines, spruces, and rs. The pinenes are often found in other oils, 3 carene less so. Like the pinenes, camphene (89) is widespread in nature. 

Turpentine is mostly composed of monoterpenes and these can have different industrial applications. Bomeol is used in cosmetics and in non-cosmetic products, such as household cleaners [145]. Carveol, linalool, myrcene, a- and (3-pinene, phellandrene and terpineol are used in the food, perfume, and cosmetics industry as fragrance and to impart flavors to foods [133, 146-149]. Also, it has been reported that turpentine could be an interesting resource for the pharmaceutical industry due... 

Another use of myrcene is the synthesis of pheromones that can be used as traps for insects. M3Tcene can be found in many plants, but its extraction would not be economical, so industrially it is obtained by pyrolysis of p-pinene, which is contained in turpentine. 

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