Ricinoleic acid synthesis

The most attractive method for production of pure 9,ll-c,t-CLA is through the dehydration of ricinoleic acid. Synthesis from this relatively inexpensive starting material has proven elusive as it is difficult to control the formation of dehydration products (124). Synthesis of 9,ll-c,t-CLA from ricinoleic acid has been reported (125), which, although an efficient reaction, uses expensive elimination reagents such as l,8-diazobicyclo-(5,4,0)-undecene. For most applications, the high cost of the elimination reagent increases the production cost beyond the level at which commercial production of CLA is economically viable. 

Teomim et al. [406] reported the synthesis of ricinoleic acid and hydrogenated ricinoleic acid (hydroxystearic acid)-based monomers, which were synthesized from the attachment of a carboxylic acid side chain via a hydrolyzable ester bond to the hydroxy group (succinic acid/maleic acid). These monomers were... 

Fatty acids have been used previously in the development of polymers for biomedical applications as they are considered to be inert, inexpensive and biocompatible. The main fatty acids which are used as a base for synthesis of biomedical polymers (polyanhydrides) are stearic acid (/), erucic acid (C22 unsaturated fatty acid) dimer (2), bile acid dimer (i), ricinoleic acid 4) and other fatty acids (5), middle long carbon chain (C12 - 15) dibasic acids, such as dodecanedioic, brassylic acid, tetradecandioic acid and pentadecandioic acid (/). 

The incorporation of fatty acids into a polyanhydride chain was investigated using two fatty acids lithocholic acid and ricinoleic acid. Lithocholic acid containing polyanhydrides (Figure 2) were prepared by two step synthesis. Polyanhydrides reached molecular weights of 21000-115000 Da, depending on the polymer composition. Release of model drugs from these polymers showed sustained release of 5FU for almost 3 weeks and triamcinolone for 4 weeks (22). 

Ricinoleic acid is a bifunctional fatty acid containing a hydroxy group along the fatty chain. The presence of both carboxylic and hydroxyl groups allows incorporation of ricinoleic acid into a polymer backbone by formation of an ester bond. The synthesis of poly(ester-anhydride) contains two steps trans-... 

Synthesis of CLA by Dehydration of Ricinoleic Acid (12-Hydroxy-c/s-9-Octadecadienoic Acid)... 

Hayes, D.G. Lipase-catalyzed synthesis of poly-hydric alcohol-poly(ricinoleic acid) ester star polymers. Polym. Prepr. (Am. Chem. Soc., Div. Polym. Chem.) 2005, 46 (1), 276-277. 

Other modifications of vegetable oils in polymer chemistry include the introduction of alkenyl functions, the study of novel polyesters and polyethers and the synthesis of semi-interpenetrating networks based on castor oil (the triglyceride of ricinoleic acid) [42], and also the production of sebacic acid and 10-undecenoic acid from castor oil [44]. Additionally, the recent application of metathesis reactions to unsaturated fatty acids has opened a novel avenue of exploitation leading to a variety of interesting monomers and polymers, including aliphatic polyesters and polyamides previously derived from petrochemical sources [42, 45]. 

The synthesis of AA by ozonolysis of OA or ricinoleic acid is known since the beginning of the twentieth century [15-17]. The key intermediates and products of the method are in accordance with the still-accepted mechanism developed by Criegee [18] (Scheme 20.1). 

One of our major areas of development was the synthesis and study of the chromatographic (8-10), spectroscopic (11-14), and spectrometric properties of a large number of heteroaromatic fatty acid derivatives (each containing either a furan, pyrrole, thiophene, selenophene, or tellurophene nucleus). These fatty acid derivatives were obtained by total synthesis or by partial synthesis from polyunsaturated unsaturated fatty acids (12,13,15-18) and unsaturated hydroxylated fatty acids, such as ricinoleic acid (from castor oil) (19-24). In this range of heteroaromatic fatty acid derivatives, only fatty acids containing a furan nucleus are found in nature (lipid extracts of the pike and salmon and from the latex of the rubber plant) (25-29). A typical method for the preparation of a disub-... 

B. S. Rao and A. Palanisamy, Synthesis, photo curing and viscoelastic properties of triacrylate compositions based on ricinoleic acid amide derived from castor oil . Prog Org Coat, 2008,63,416-23. 

Scheme 3.11 The synthesis of ABA triblock copolyesters based on ricinoleic acid and L-lactide. ROP Ring-opening polymerisation [23]...

Cramail and co-workers [40] described the synthesis of two linear and branched a,(0-diene monomers from castor and vernonia oils to develop linear low-density polyethylene and very low-density polyethylene-like polyesters. Methyl 10-undecenoate and 12-hydroxystearic acid, obtained from ricinoleic acid, were employed for the synthesis of the branched a,ro-diene, and a second monomer of similar structure (but linear) was synthesised from methyl 10-undecenoate and 1,12-dodecanediol (obtained from vernolic acid). Further ADMET copolymerisation of the dienes led to a series of copolyesters with Mn values of 14-62 kDa, Tm of 13.2-87.4 °C, and with various degrees of branching depending on the feed ratio between the two a,(0-dienes. 

There is presumptive evidence that the proplastid and the ofl storage organelles differ in function. Thus, Yamada and his colleagues, as well as Simcox et al., have shown that proplastids isolated from developing castor bean endosperm synthesize only oleic acid. However, the major product of fatty acid synthesis in these seeds is triricinoleoylglycerol. Galliard and Stumpf (1966) have shown that the synthesis of ricinoleic acid involves a microsomal preparation (presumably endoplasmic reticulum) which hydroxylates oleoyl-... 

Palaskar, DV Boyer, A Cloutet, E Alfos, C Cramail, H. Synthesis of biobased polyurethane from oleic and ricinoleic acids as the renewable resources via the AB-Type self-condensation approach. Biomacromolecules, 2010, 11, 1202-1211. 

Scheme 5.3 Synthesis of ricinoleic acid based monomers. RAM, ricinoleic acid maleate RAS, ricinoleic acid succinate HSAS, hydroxy stearic acid succinate.

The condensation reaction of diacetyl mixed anhydrides of aromatic or aliphatic diacids is carried out in the temperature range 150—200°C. The synthesis of polyanhydride from RA half-esters with maleic and succinic anhydride has been reported (Teomim and Domb, 1999). Ricinoleic acid maleate (RAM) or ricinoleic acid succinate (RAS) diacid half esters were polymerised by melt condensation as shown in Scheme 5.3. 

Several tissues have been used to study the mechanism of fatty acid synthesis, particularly the avocado mesocarp, spinach and lettuce chloroplasts, and etiolated barley seedlings, but some major advances have been made from studies of maturing oil-bearing seeds, e.g. castor bean (in which 90% of the fatty acid content is ricinoleic acid) and safflower, Carthamus tine tor ius (76% linoleic and 1% oleic). Oleic acid plays a central role in plant fatty acid anabolism as the precursor of the major unsaturated fatty acids, e.g. it is the first detectable fatty acid formed when acetate is fed to the developing castor bean and is itself a precursor of ricinoleic acid. 

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