Acid Erucic

Reactions in which a product remains in the him (as above) are complicated by the fact that the areas of reactant and product are not additive, that is, a nonideal mixed him is formed. Thus Gilby and Alexander [310], in some further studies of the oxidation of unsaturated acids on permanganate substrates, found that mixed hlms of unsaturated acid and dihydroxy acid (the immediate oxidation product) were indeed far from ideal. They were, however, able to ht their data for oleic and erucic acids fairly well by taking into account the separately determined departures from ideality in the mixed hlms. 

Fig. 35 Fluorescence scan of the dansyl semicadavende denvatives of 1 behenic acid 2 erucic acid, 3 steanc acid, 4 oleic acid, 5 linoleic acid, 6 linolenic acid...

Erucasaure, /. erucic acid, eruieren, v.t. ascertain, find out. 

Fatty acids, both saturated and unsaturated, have found a variety of applications. Brassilic acid (1,11-un-decanedicarboxylic acid [BA]), an important monomer used in many polymer applications, is prepared from erucic acid (Scheme 2), obtained from rapeseed and crambe abyssinica oils by ozonolysis and oxidative cleavage [127]. For example, an oligomer of BA with 1,3-butane diol-lauric acid system is an effective plasticizer for polyvinylchloride. Polyester-based polyurethane elastomers are prepared from BA by condensing with ethylene glycol-propylene glycol. Polyamides based on BA are known to impart moisture resistance. 

Other alkenoic acids that have been dimerized with retention of configuration at the double bond are oleic acid (23 % dimer yield), elaidic acid (44%) [143], and erucic acid (40%) [144]. 

Muscalure 20, the pheromone of the housefly has been prepared from oleic acid or erucic acid, similarly (Z)-l 1-heneicosene 21, the synergist of muscalure was obtained [189]. The intermediate 22 for the pheromone of the Cabbage looper was prepared using (Z)-methyl-4-octenedioate [166bJ, that was obtained by partial ozonolysis of (Z,Z)-l,5-cyclooctadiene. Similarly disparlure 23, the sex attractant of the gypsy moth, has been synthesized by two successive crossed-couplings with (Z)-4-octene dioate [191],... 

By way of a specific example let us consider erucic acid. The main commercial source of erucic acid is a specially bred form of rape seed (HEAR) as pointed out above. With European consumption being around 60 000 tpa almost 40 000 ha of land are used to grow rapeseed for erucic acid production in Europe. The high level of erucic found in this type of rape seed oil make it unsuitable for human consumption, owing to the indigestibility of such large amounts of this acid. Erucic acid is also the major fatty acid to be found in nasturtium and crambe seeds (up to 75% and 56% respectively), and it is also found in the salad herb, rocket. 

The oil thus obtained, which should amount to 1460-1600 cc., is dissolved in three times its volume of 95 per cent ethyl alcohol and the mixture cooled to —10 to o°, when the erucic acid crystallizes (Note 3). After six to eight hours at this temperature, the crude erucic acid is collected on a basket centrifuge (Note 4). The mother liquor, on chilling, yields a second crop of erucic acid. The combined product (800-1100 g.) melts either partially or wholly at room temperature, owing to the presence of oleic acid. It is dissolved in an equal volume of alcohol,... 

The crystallization is best accomplished by cooling for several hours at o°. Cooling in an ice-salt mixture is much quicker but the erucic acid so obtained contains more oleic acid. 

The centrifuge affords an easy way of filtering the erucic acid, since, if the acid is not quickly separated from the mother liquor, it melts and makes separation impossible. If a centrifuge is not available, the acid must be filtered at o°, which is inconvenient except during cold weather. 

The mother liquors from the recrystallizations may be combined, evaporated, and distilled under reduced pressure, taking two equal fractions. The lower (b.p. 200-220°/ mm.) consists mainly of oleic acid the higher (b.p. 220-250°/ mm.) is solid at 20° and yields a further quantity of erucic acid on recrystallization. 

Oil Palmitic acid Stearic acid Oleic acid Linoleic acid Linolenic Elaeostearic Ricinoleic Gondoic Erucic acid... 

Z 11 eicosenoic (gondoic) acid, Z 13 docosenoic (erucic) acid, 11,12 dihydroxyeicosanoic acid, 13,14 dihydroxydocosanoic acid Oils from Brassicaeae seeds [12,44,45]... 

Fatty acids have also been converted to difunctional monomers for polyanhydride synthesis by dimerizing the unsaturated erucic or oleic acid to form branched monomers. These monomers are collectively referred to as fatty acid dimers and the polymers are referred to as poly(fatty acid dimer) (PFAD). PFAD (erucic acid dimer) was synthesized by Domb and Maniar (1993) via melt polycondensation and was a liquid at room temperature. Desiring to increase the hydrophobicity of aliphatic polyanhydrides such as PSA without adding aromaticity to the monomers (and thereby increasing the melting point), Teomim and Domb (1999) and Krasko et al. (2002) have synthesized fatty acid terminated PSA. Octanoic, lauric, myristic, stearic, ricinoleic, oleic, linoleic, and lithocholic acid acetate anhydrides were added to the melt polycondensation reactions to obtain the desired terminations. As desired, a dramatic reduction in the erosion rate was obtained (Krasko et al., 2002 Teomim and Domb, 1999). 

Technical report series no. 21 (June 2003) Erucic acid in food-A toxicological review and risk assessment Food Standards, Australia, New Zealand. 

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