Wild mustard (Brassica juncea L.) oil is evaluated as a feedstock for biodiesel production. Biodiesel was obtained in 94 wt.% yield by a standard transesterification procedure with methanol and sodium methoxide catalyst. Wild mustard oil had a high content of erucic (13(Z)-docosenoic; 45.7 wt.%) acid, with linoleic (9(Z), 12(Z)-octadecadienoic; 14.2 wt.%) and linolenic (9(Z), 12(Z),15(Z)-octadecatrienoic; 13.0 wt.%) acids comprising most of the remaining fatty acid profile. The cetane number, kinematic viscosity, and oxidative stability (Rancimat method) of the methyl esters was 61.1, 5.33 mm 2 s -1 (40°C) and 4.8 h (110°C), respectively. The cloud, pour and cold filter plugging points were 4, -21 and -3°C, respectively. Other properties such as acid value, lubricity, free and total glycerol content, iodine value, Gardner color, specific gravity, as well as sulfur and phosphorous contents were also determined and are discussed in light of biodiesel standards ASTM D6751 and EN 14214. Also reported are the properties and composition of wild mustard oil, along with identification of wild mustard collected in Brazil as Brassica juncea L. (2n = 36) as opposed to the currently accepted Sinapis arvensis L. (2n = 18) classification. In summary, wild mustard oil appears to be an acceptable feedstock for biodiesel production.

We report a facile Ru-catalyzed route to alkenes from unsaturated fatty acids (alkenoic fatty acids) via readily accessible catalyst precursors, [Ru­(CO)­2RCO2] n and Ru3(CO)12. The catalyst apparently functions in a tandem mode by dynamically isomerizing the positions of double bonds in an aliphatic chain and, subsequently, decarboxylating specific isomers with lower activation barriers. Substrates capable of tandem isomerization-decarboxylation processes (oleic acid, undecylenic acid) are readily converted to mixtures of alkenes. A catalytic cycle is proposed that relies on isomerization positioning double bonds proximate to the acid function to enable facile decarboxylation. To elucidate the proposed mechanistic pathway, substrates that do not undergo decarboxylation under these catalytic conditions (methyl oleate) are compared with those that cannot isomerize the position of unsaturation (cinnamic acid). Both were shown to be operational under these catalytic reaction conditions. Another illustrative comparison shows that the saturated octadecanoic acid is 28 times less reactive than the unsaturated counterpart when reacted using this precatalyst.

Recently, ruthenium-catalyzed isomerization–decarboxylation of fatty acids to give alkene mixtures was reported. When the substrate was oleic acid, the reaction yielded a mixture consisting of heptadecene isomers. In this work, we report the compositional analysis of the mixture obtained by triruthenium dodecacarbonyl catalyzed decarboxylation of oleic acid. Surprisingly, the most prominent single compound identified was heptadecane at approximately 18 wt %. A mixture of heptadecene isomers constituted the greatest percentage of the product (>75%), where all positional isomers were confirmed by GC–MS analysis of dimethyl disulfide derivatives of the product. Besides these components, minor amounts of alkyl aromatics, each with a total of 17 carbons atoms, among them undecyl benzene, were observed. Minor amounts of other compounds, such as shorter-chain hydrocarbons and polyunsaturated C17 compounds, were also observed. A reaction pathway to explain the existence of these products is proposed. Heptadecenes first cyclize to the observed alkyl aromatics under liberation of hydrogen with the formed hydrogen, then in turn hydrogenating some heptadecenes to heptadecane. Thus, triruthenium dodecacarbonyl is suggested to also promote dehydrogenation, aromatization, and hydrogenation under the present conditions. Since the product mixture consisted mainly of long-chain hydrocarbons, its properties regarding diesel fuel application were studied and compared to biodiesel and petroleum diesel. The cetane number (86.9) was high, but oxidative stability (3.4 h; EN 15751) and cold flow (cloud point −1 °C) would require improvement to meet fuel specifications. All other fuel properties were within the limits prescribed in the petrodiesel standards.

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Glycerol was reacted with 4-methoxy cinnamic acid to prepare the corresponding 4-methoxy cinnamoyl glycerol. The reaction proceeded in toluene under reflux conditions with p-toluenesulfonic acid catalyst. Reaction of equimolar amounts of reactants produced the monoester in 20% yield after 2 h. The product was isolated and characterized by FTIR, mass spectrometry, and NMR techniques. Results of mass spectrometry and NMR experiments showed that the ester linkage formed between the carboxylic acid and the primary hydroxyl of glycerol. The ester displayed strong absorbance between 250 and 350 nm and shows potential as a UV filter in formulations where hydrophilic compounds are advantageous.

Ruthenium-catalyzed decarboxylation of 9-cisoctadecenoic is a path to produce biobased olefins. Here, a mechanistic study of this reaction was undertaken utilizing a closed reaction system and a pressure reactor. The proposed mechanism of an isomerization followed by a decarboxylation reaction was consistent with a mathematical kinetic model. That same model was able to accurately predict CO 2 evolution. Additionally, computational chemistry was used to determine that the barrier of the oleic acid decarboxylation reaction is 249 kJ mol −1 . Using the new information, the efficacy of the decarboxylation reaction was improved to an overall catalytic efficiency of 850 total turnovers.

Conjugated linoleic acid (CLA; 9c,11t-18:2) and CLA isomers have been reported, in animals, to exhibit a variety of health-related benefits. Silver ion high-performance liquid chromatography (Ag-HPLC) was found to provide better resolution of the isomers than gas chromatography. Most commercially available samples of CLA, prepared by base-catalyzed isomerization of linoleic acid (9c,12c-18:2), are composed of mixtures of four major isomers. While these isomers have been characterized, we found significant changes in CLA isomer rations within samples obtained from the same producer/commercial supplier over a period of 1.5 yr. In the first sample, the four cis/trans isomers (8t,10c-18:2, 9c,11t-18:2, 10t,12c-18:2 and 11c,13t-18:2) were present in a ratio of approximately 1:2:2:1, while in the second sample they were present in almost equal proportions. If indeed certain daily levels of CLA intake are required to produce suggested health benefits in humans, changes in concentrations of specific CLA isomers could significantly impact these effects. Care must be taken to analyze the CLA used in human and animal studies.

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