Chemicals 1-octadecene

These reactions, which are believed to occur predominantly inter-molecularly, are capable of producing intermediates which hold some potential as precursors for important chemical products. For example, metathesis of olive oil, which consists chiefly of triglycerides of oleic acid, produces the glyceride of 9-octadecene-l,l8-dioic acid from which can be obtained, after saponification, acidification, and low-temperature crystallization, the free acid, which can be transformed by intramolecular condensation to civetone. 

Fig. 44. An optical resonance spectrum from Tallin and Davis (1990) for the chemical reaction between an octadecene droplet and bromine vapor. Reprinted with permission from J. Aerosol Sci. 21, 73-86, Tallin, D. C., and Davis, E. J., <3opyr t 1990, Pergamon Press pic.

Thus, if the monochromator is set to a wavenumber of 650cm", the formation of the C—Br bond can be recorded as a function of time during a chemical reaction between bromine and an olefin. Buehler used this method to follow the bromine/octadecene reaction. It should be pointed out that the Raman scattering is a function of droplet size as well as composition, and unlike bulk Raman it is complicated by the morphological resonances... 

Fig. 49. The levitation voltage and the Raman peak height associated with the C—Br bond for the chemical reaction between 1-octadecene and bromine (from Buehler, 1991).

Even though it is commonly referred to as sphingosine, its proper chemical name is D-erythro-1,3-dihydroxy-4, 5-trans-octadecene. Other satisfactory names are rran.v-4-sphingosine, sphing-4-enine, or sphingenine in any event, all the naturally occurring sphingolipids contain only the D-erythro form. 

More chemical specificity is represented by the structure of the sex pheromone released by females of the Korean population of the apple leaf miner Lyonetia prunifoliella. The main compound is 10,14-dimethyl-l-octadecene (M25), which is accompanied by minor amounts of the saturated hydrocarbons, 5,9-dimethyloctade-cane and 5,9-dimethylheptadecane 902 Earlier, the three compounds were reported to be components of the sex pheromone for the North American population of the moth.903 During bioassays in Korea, all (S, -configured isomers proved to be electrophysiologically active, whereas (105,145)-dimethyloctadec-l-ene elicited the strongest response. In contrast to the North American insects, (105,145)-M25 was found to attract the moths as a single compound. In the case of the Lyonetia compounds, the structure M25 suggests the incorporation of two propanoate units interrupted by an acetate unit. 

SCHEME 9. Possible mechanism for the formation of Ln203 nanoplates and nanodiscs (OAH = oleic acid, OM = oleylamine, ODE = 1-octadecene). Reprinted with permission from Reference 462. Copyright 2007 American Chemical Society... 

Fig. 2. Chemical structures of typical slick-forming compounds, a.) oleyl alcohol (Z-9-octadecen-l-ol OLA), b.) oleic acid methyl ester (methyl Z-9-octadecenoate OLME), and c.) methyl palmitate (methyl hexadecanoate PME)...

Ei cosene-1 Hexadecene-1 Octene-1 intermediate, specialty industrial chemicals gasoline additives C20-24 alpha olefin Octadecene-1 intermediate, specialty industrial chemicals lubricants Octadecene-1... 

C20-24 alpha olefin Octadecene-1 intermediate, specialty industrial chemicals polymers... 

Ricinic (castor) oil is a special oil which is of significant use in the emulsifier industry. This consists of 85% of esters of c/5-12-hydroxy-9-octadecenic acid. The free hydroxy group is used as a starting point for the formation of chemical derivatives such as esters or ethers, for instance, in polyethoxylated or polyglycerol surfactants. 

Because the free enthalpy change in this type of reaction is virtually zero, the result at equilibrium is a random distribution of the alkylidene groups. Thus, starting with methyl oleate, the equilibrium mixture consists of 50 mol% of the starting material and 25 mol% of each of the products 9-octadecene and dimethyl 9-octadecene-1,18-dioate. The cis/trans ratio of the reaction products is also in accordance with thermodynamics. This demonstrates that - in the presence of a suitable catalyst - the metathesis of unsaturated fatty acid esters provides a convenient and highly selective route to unsaturated diesters. Unsaturated diesters are important intermediates for the production of useful chemical products such as macrocyclic compounds. For instance, the diester obtained by metathesis of ethyl oleate has been subjected to a two-step reaction sequence, i.e. a... 

From a synthetic point of view, cross-metathesis reactions are very useful for the production of fine chemicals, which often can hardly be obtained by other means. An example is the synthesis of 1-triacontanol, CH3(CH2)28CH20H, a plant growth stimulant. This synthesis was performed in a relatively simple two-step process by cross-metathesis of methyl erucate with 1-octadecene in the presence of a WCl6/Me4Sn catalyst, equation (7), followed by hydrogenation over a Cu/Zn catalyst of the ester thus obtained [14]. 

Due to the fact that the conversion of oleochemical feedstocks into more valuable chemicals appears especially attractive, an economical metathesis of fats and oils and their derivatives should be considered seriously by the oleochemical industry. It has perspectives especially for production of products with a high added value. As an example, Figure 1 presents a process scheme for the (batch-wise) production of dimethyl octadecene-l,18-dioate from methyl oleate via metathesis in the presence of a supported Re207 catalyst [68]. 

Fig. 6.4.5. Methods used to analyze the aliphatic components of suberin. Top left chemical methods used to depolymerize suberin. Top right gas-liquid chromatogram of the mixture of monomers generated by LiAlD4 treatment of suberin from the chalazal region of the inner seed coat of Citrus paradisi the components are trimethylsilyl ethers of 1,16-dihydroxyhexadecane (1), 1,18-dihydroxy-octadecene (2), 1,9,18-trihydroxyoctadecene (3), 1,9,18-trihydroxyoctadecane (4), 1,9,10,18-tetrahy-droxyoctadecane (5), 1,22-dihydroxydocosane (6), 1,24-dihydroxytetracosane (7). Bottom mass spectrum of component 2 from gas chromatogram (111)...

Aqueous thickening agent 1-Octadecene Methyl vinyl ether South Africa 4,466 1970 Imperial Chemical... 

FIGURE4.40 EI-MS spectrum of (Z)-9-octadecen-4-olide and its dimethyldisulfide derivative showing. Cleavage between thioether groups (from Cosse, A. A., et al, Journal of Chemical Ecology 27 (2001) 1841-1853.)... 

In the presence of (-l-)-ephedrine, (E)-l-acetylcyclooctene (50d) photoisomerizes to enantiomeric (Z)-isomer, which is trapped by cyclopentadiene to give a Dies-Alder adduct in 22 %ee. A stable sila analogue of (E)-cycloheptene (79E) was prepared," and its enantiomers were resolved by chiral HPLC."° However, direct and sensitized asymmetric photoisomerizations afford the (E)-isomer in low chemical and optical yields." Direct irradiation at >280 nm of doubly bridged (Z)-D2ij-l(10)-bicyclo[8.8.0]octadecen-2-one (80Z) in diethyl (-I-)-tartrate as solvent affords the levorotatory (E)-isomer with an E/Z ratio of 7. 22> 23... 

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