Terpenes Olefine

Other Peroxyacids. Benzeneperoxyseleninic acid has been prepared in situ from benzeneseleninic acid and hydrogen peroxide and is used to epoxidize terpenic olefins and Baeyer-Villiger oxidation of cyclic ketones. 

Moreover, the catalytic activity of a reused catalyst is completely preserved after several cycles, and the filtrate is catalytically inactive. This supported and reusable P-W catalyst has also been applied for the epoxidation of a series of terpene olefins (356). The productivity of the catalyst for the conversion of these bulky molecules is superior to that reported for Ti-MCM materials, for example. The stereochemical and regioselective characteristics of W catalysis are preserved in the supported P-W catalyst. For instance, geraniol is epoxidized at the 2,3 position, affording the tram product. 

Acetoxylation is a valuable method for the introduction of an OH group into organic compounds, which can be used for further syntheses. In Section 3.3.14.2 it has been mentioned that acetoxylation of higher and cyclic olefins with palladium salts, or catalyzed by palladium salts or metal, mostly leads to allylic derivatives. This also takes place in the catalytic acetoxylation of terpenic olefins [79, 80]. 

Chirally modified ruthenium clusters have also been used for a kinetic resolution of enantiomers in the catalytic hydrogenation of non-functiona-lized terpene olefins (Scheme 5) The hydrogenation of a-pinene (IR,5R 27 S,5S 28) leads in principle to the cis- and /rans-pinanes (11 ,25,5/ 29 15,21 , 55 30 IR,2R,5R 31 IS",25,55 32). When a racemic mixture of both a-pinene enantiomers (27 and 28) is hydrogenated in the presence of the (15,25,35,5.R)-isopinocampheyl cluster HRu3(CO)9[//3, //2-NEt-... 

Bromomethyl)- or (hydroxymethyl)cycIopropane derivatives undergo acid-catalyzed homoallyiic rearrangements to yield trans-olefins (J.P. McCormick, 1975 S.F. Brady, 1968 M. Julia, 1974). This rearrangement is the basis of Julia s terpene synthesis (see. p. 70). 

Hydrocarbon resin is a broad term that is usually used to describe a low molecular weight thermoplastic polymer synthesized via the thermal or catalytic polymerization of coal-tar fractions, cracked petroleum distillates, terpenes, or pure olefinic monomers. These resins are used extensively as modifiers in the hot melt and pressure sensitive adhesive industries. They are also used in numerous other appHcations such as sealants, printing inks, paints, plastics, road marking, carpet backing, flooring, and oil field appHcations. They are rarely used alone. 

Hydrocarbons, compounds of carbon and hydrogen, are stmcturally classified as aromatic and aliphatic the latter includes alkanes (paraffins), alkenes (olefins), alkynes (acetylenes), and cycloparaffins. An example of a low molecular weight paraffin is methane [74-82-8], of an olefin, ethylene [74-85-1], of a cycloparaffin, cyclopentane [287-92-3], and of an aromatic, benzene [71-43-2]. Cmde petroleum oils [8002-05-9], which span a range of molecular weights of these compounds, excluding the very reactive olefins, have been classified according to their content as paraffinic, cycloparaffinic (naphthenic), or aromatic. The hydrocarbon class of terpenes is not discussed here. Terpenes, such as turpentine [8006-64-2] are found widely distributed in plants, and consist of repeating isoprene [78-79-5] units (see Isoprene Terpenoids). 

Phosphorus(V) sulfide reacts with olefins, amines, Grignard reagents, and terpenes (6,26) as follows ... 

Paint and varnish manufacturing Resin manufacturing closed reaction vessel Varnish cooldng-open or closed vessels Solvent thinning Acrolein, other aldehydes and fatty acids (odors), phthalic anhydride (sublimed) Ketones, fatty acids, formic acids, acetic acid, glycerine, acrolein, other aldehydes, phenols and terpenes from tall oils, hydrogen sulfide, alkyl sulfide, butyl mercaptan, and thiofen (odors) Olefins, branched-chain aromatics and ketones (odors), solvents Exhaust systems with scrubbers and fume burners Exhaust system with scrubbers and fume burners close-fitting hoods required for open kettles Exhaust system with fume burners... 

In addition to the above-described terpenes proper, there are a few other hydrocarbons which may be conveniently dealt with here. These are salvene, the so-called olefinic terpenes, myrcene and ocimene, the terpene homologues, cantharene, santene, and a hydrocarbon of the formula CjjHjg found in sandalwood oil, and the diterpene phyllocladene. 

Koschelew has recently prepared a closely related olefinic terpene, which he has termed /3-myrcene, by treating isoprene in a sealed tube to 80° to 90° for five days. This body has the constitution —... 

Corrosion inhibitor To protect metal surfaces, particularly bearing surfaces (copper, silver, lead) against corrosion Zinc dialkyidithiophosphates, sulphurised olefins, sulphurised terpenes... 

Molybdenum hexacarbonyl [Mo(CO)6] has been vised in combination with TBHP for the epoxidation of terminal olefins [44]. Good yields and selectivity for the epoxide products were obtained when reactions were performed under anhydrous conditions in hydrocarbon solvents such as benzene. The inexpensive and considerably less toxic Mo02(acac)2 is a robust alternative to Mo(CO)6 [2]. A number of different substrates ranging from simple ot-olefms to more complex terpenes have been oxidized with very low catalytic loadings of this particular molybdenum complex (Scheme 6.2). The epoxidations were carried out with use of dry TBHP (-70%) in toluene. 

The reaction of olefin sulfation and its possibilities has been extensively studied [3-10] and it was used to produce alcohol sulfates. Dry distillation of spermaceti gives palmitic acid and cetene-1, which can be sulfated with sulfuric acid to give cetyl-2 sulfate [11]. Other surfactants were obtained from olefins produced from natural substances, such as alcohol sulfates by sulfation of olefins from decarboxylation of oleic acid [12], by sulfation of olefins made by dehydrating hydroabietyl alcohol, by direct sulfation of abietyl alcohol [13,14], or by sulfation of natural terpenes [15]. 

One or both carbonyls in /3-diketones can be reduced, as well as the carbonyl function in acyl cyanides (210). Similar treatment of a,/3-unsat-urated ketones and aldehydes can lead to the saturated carbonyl products via selective reduction of the olefinic bond (207, 208, 210) see Eq. (51) in Section III,A,4. Some terpenes (a- and /3-ionone, pulegone) were reduced in this way (208). Platinum(II) phosphine complexes have been used for the hydrosilylation of saturated ketones and could be used for the reduction (211). 

Olefins with allylic hydrogen, chloro- and fluoroolefins, terpenes, tetrahydronaphthalene > c=c<... 

A closely related dicationic platinum complex has been shown to transform efficiently /3-citronellene into cis-thujane in a highly diastereoselective manner, which mimics terpene biosynthesis.362 Also, using platinum(n) catalysis, Widenhoefer has reported an intramolecular alkylation of indoles with unactivated olefins, which can be carried out in an enantioselective fashion (Scheme 99).363... 

Cyclic olefins and diolefins form much more aerosol than 1-alkenes that have the same number of carbon atoms (for example, cyclohexene 1-hexene, and 1,7-octadiene 1-octene). The same effect of chain length and double-bond position is observed for diolefins (1,7-octadiene > 1,6-heptadiene > 1,5-hexadiene, and 1,7-octadiene 2,6-octadiene). Heavier unsaturated cyclic compounds, such as indene and terpenes, form even more aerosol. 

The gas-phase reactivity of various terpenes has been measured. Stephens and Scott were the first to include two terpenes (pinene and a-phel-landrene) with their study of the relative reactivity of various hydrocar ns. Both monoterpenes showed the high reactivity predicted by their olefinic structure. Conversion of nitric oxide to nitrogen dioxide in e presence of isoprene is at a rate intermediate between those for ethylene and trans-2-butene, and Japar et al, reported rate constants for the a-pinene and terpinolene-ozone reactions. Grimsrud et a/. measured the rate con-... 

Aerosol formation from terpenes has not been extensively investigated. Only one olefinic terpene, a-pinene, has been studied. 

---