The synthesis and properties of a number of novel branched Jatropha curcas L. oil (JO) derivatives containing vicinal di-ester units in the fatty acid chains are reported. Both the length (acetyl vs. hexanoyl) and the stereochemistry of the vicinal di-ester units (cis vs. trans) were varied. The compounds were prepared by two different synthetic approaches using catalytic chemistry. The first approach involves epoxidation of JO using a Sharpless epoxidation with methyltrioxorhenium as the catalyst to give epoxidized JO (1), followed by an esterification reaction with the corresponding anhydrides using ammonium-12-molybdophosphate (AMP) as catalyst to give trans-di-esters of JO (4a, 4b). The second approach is based on the dihydroxylation of JO using either the Prilezhaev method, resulting in trans-diols of JO (2), or the Upjohn method using osmium tetroxide as catalyst to give cis-diols of JO (3). In subsequent steps, the diols were esterified with acetic-or hexanoic anhydride using dimethylaminopyridine as catalyst to produce the corresponding cis-and trans-di-esters of JO (5a, 5b, 6). The best cold flow properties (lowest pour-and cloud point, crystallization and melting temperature) were obtained for JO with hexanoyl branches in a trans orientation (5b, pour point of À148C, melting point of À58C, and crystallization temperature of À258C) and these values are considerably better than for the JO source.Practical applications: Jatropha curcas L. oil (JO) is a toxic oil with potential applications not only as a green biodiesel but also as a feedstock for the oleochemical industry. The toxicity prohibits the use in food products but does not interfere with technical applications. Here we report studies on the synthesis of interesting JO derivatives (epoxidized, dihydroxylated, and branched compounds) that could be useful starting materials for a range of derivatives with a broad application perspective. The branched JO derivatives with vicinal di-ester units in the fatty acid chains have cold flow properties (pour-and cloud point, melting point and crystallization temperature) considerably better than the original JO. In addition, the oxidative stability was also improved significantly. These novel branched JO derivatives may have interesting applications as cold-flow improvers for biodiesel or as biolubricants.

An experimental study to modify Sterculia foetida L. oil (STO) or the corresponding methyl esters (STO FAME) to branched ester derivatives is reported. The transformations involve conversion of the cyclopropene rings in the fatty acid chains of STO through various catalytic as well as stoichiometric reactions. Full conversion of the cyclopropene rings was obtained using Diels-Alder chemistry involving cyclopentadiene in water at 408C without the need for a catalyst. Olefin metathesis reactions were performed using a Grubbs 2nd generation catalyst and cyclopropene ring conversion was !99 and 54 mol% with 2,3-dimethyl-2-butene and 1-octene, respectively. Oxidation reactions were performed using established epoxidation (Sharpless) and dihydroxylation (Prilezhaev) protocols using aqueous hydrogen peroxide as the oxidant. For both reactions, full conversion of the cyclopropene rings was obtained at RT to yield the corresponding a,b-unsaturated ketone in good selectivities. Rearrangement reactions of the cyclopropene rings to the corresponding conjugated diene were successfully performed using homogeneous and heterogeneous palladium catalysts. Excellent conversions (!99%) were obtained using homogeneous palladium catalyst in a biphasic cyclohexane-water mixture (1:1) at 908C. Relevant cold flow properties of all products were determined and compared to crude STO and STO FAME. Best results were obtained for the metathesis products of STO with 1-octene, with a cloud point (CP) and pour point (PP) of À128C.Practical applications: The S. foetida L. tree produces a tropical oil with high potential to be converted to various oleochemical products. The oil contains cyclopropene rings in the fatty acid chains which are known to be very reactive and as such excellent starting materials for various chemical modification reactions. We here report an experimental study on the modifications of STO into novel branched ester derivatives which are prospective products for a range of applications. Examples are the use as cold-flow improvers for biodiesel or biolubricants (ester derivatives with long, aliphatic branches), as reactive building block material for resin, coatings and/or packaging application (derivatives containing unsaturated (cyclic) structures in the fatty acid chains). Abbreviations: APT, attached proton test; 1, methyl esters of STO; 2, methyl esters of Diels-Alder reaction products; 3a, product of metathesis reaction of STO with 2,3-dimethyl-2-butene; 3b, product of metathesis reaction of STO with 1-octene; 4a, methyl esters of 3a; 4b, methyl esters of 3b; 5, product of epoxidation reaction; 6, product of hydroxylation reaction; 7, product of 1,4-addition reaction of STO with noctylMgBr; 8, methyl esters of 7; 9, methyl esters of rearrangement

This paper describes an experimental study on the application of metal triflate salts for the (trans‐) esterification of fatty esters (triolein, methyl oleate, methyl linoleate), fatty acid (oleic acid), as well as Jatropha curcas L. oil with methanol and higher alcohols (ethanol, n‐propanol, iso‐propanol, iso‐butanol, tert‐butanol). The effect of the metal type (scandium, bismuth, aluminium, lanthanum, copper, zinc) and process conditions on reaction performance were evaluated. Highest conversions were obtained with Al(OTf)3. Reaction of triolein with methanol gave 99 mol% conversion at 165 °C for 1 h and the main product was the methyl ester. In addition, partial methoxylation of the carbon–carbon double bonds in the fatty acid chains was observed, though their fraction in the mixture was less than 20 mol%. The trans‐esterification reaction was also successfully performed using higher alcohols, giving >95 % conversions for ethanol, n‐propanol, iso‐propanol and iso‐butanol, whereas tert‐butanol was not reactive. For the reaction of oleic acid with methanol, quantitative esterification, partial methoxylation of the carbon–carbon double bonds and the formation of small amounts of a lactone was observed. The methodology using Al(OTf)3 was successfully performed on the trans‐esterification reaction of JO (FFA content of 2.1 wt%) with various alcohols. Key properties (viscosity, pour point and cloud points) of the (branched) Jatropha esters were determined. The best cold‐flow properties were obtained for the iso‐propyl esters of JO, with cloud point and pour point of −3 and −24 °C, respectively.