Brassidic acid

CH3(CH2)7CH=CH(CH2)uCOOH Brassidic acid trans-13-Docosenoic acid... 

Brasslosaure, /. brassic acid (brassidic acid), brat, pr. S aing. (of braten) roasts, etc, braten, v.t. roast calcine grill, broil, bake, fry bum, scorch. 

Bent hydrocarbon chains - e.g. brassidic acid trans-CH3(CH2)7CH=CH(CH2)iiCOOH), which has a straight hydrocarbon chain, gives a condensed film, whereas erucic acid (cis-CH3(CH2)7CH-CH(CH2)iiCOOH), which has a bent hydrocarbon chain, gives a very expanded Aim. 

The first recorded observation (Adam, 13) of reaction in a monolayer, made in 1926, describes the oxidation by acid permanganate of a film of oleic acid. The reaction proceeds with expansion of the film, since the double bond in the middle of the chain is converted into a dihydroxy group, which is sufficiently hydrophilic to pull the hydrocarbon chain flat on to the surface of the water. Triolein and erucic and brassidic acids all behave in the same way. Adam also observed (14) that films of 7-hydroxy-stearolac.tone, spread on alkali, hydrolyzed to 7-hydroxystearic acid. 

The steric factors influencing the course of a reaction can be modified if the reactant is spread as monomolecular film. An example of this was found by Marsden and Rideal (35) in 1938. They studied the oxidation of monolayers of erucic and brassidic acids, containing, respectively, cis and trans double bonds. The oxidant was acid permanganate in the underlying aqueous solution. The oxidation products from both acids appeared to be identical, corresponding most closely with the properties of the cis dihydroxy acid. This material, m.p. 100°C., occurs in the bulk oxidation from erucic acid only the trans unsaturated acid gives an isomer of m.p. 130°C. There is thus some evidence for a directive oxidation due to orientation at an interface. The comparison of the products of the surface reaction was made by spreading films of the various dihydroxy compounds. 

CgHj CH CH(CH2)7C00H ibid CgH. CH CH(CH2)70H ibid CgHi CH CH(CH2)iiCOOH ibid trans-9 octadecenoic acid cis-9 octadecenoic acid trans-8 octadecenyl alcohol cis-8 octadecenyl alcohol trans-13 docosenoic acid CIS-13 docosenoic acid elaidic acid oleic acid elaidyl alcohol oleyl alcohol brassidic acid erucic acid... 

Erucic Acid. 13-Docosenolc acid Al3 l4-docoseno-ic acid. C]2H4202 mol wt 338.56. C 78.04%, H 12.51%, O 9.45%. A monoethenoid acid found in the seed fats of Cru-ciferae and Tropaeolaceae. It constitutes 40 to 50% of the total fatty acids of rapeseed, mustard- and wallflower seed, and it represents up to 80% of fatty acids of nasturtium seeds, cf K. S. Markley, Fatty Acids Part I (Interscience. New York, 2nd ed., 1960) p 138-139. Prepn of a crude product hy alkaline hydrolysis of rapeseed oil Noller, Talbot, Org. Syn. eoll. vol. II, 258 (1943). A purer product is obtained by the method of Dor6e and Pepper, J. Chem. Soc. 1942, 477, which involves a fractional precipitation and crystallization. Prepn of a pure product by acid soap crystallization Chobanov el al. Chem. A Ind. (London) 1965, 606. Synthesis Bowman, J. Chem. Soc. 1950, 177, 325 Bounds et al. ibid. 1953, 2393. Treatment with nitric acid yields the trans isomer, brassidic acid, q v. Dorie. Pepper-foe. eft. Brief review E. Lower, Manuf. Chem. 56(6), 61-63 (1985). 

Many early results for erucic acid actually included total C22 fatty acids since the analysis was performed on nonpolar columns in order to save time and increase sample throughput. Present day analyses are usually carried out using polar phases, including a mixed phase which allows separation of all major fatty acids according to chain length and degree of unsaturation. Erucic acid values reported from these analyses still contain very small amounts of vaccenic and brassidic acids. It is necessary to use open tubular gas chromatography to determine these isomers. 

Brassidic Acid Brassic acid, A -docosenoie acid, trans-eructc acid, ieoerueic acid)... 

Bombykal, see H-OOl38 Bombykol, in H-OOl54 Brassicasterol, in M-OOOl 1 Brassidic acid, in D-00207 Brassylic acid, see T-00145 3-Bromo-2-(3-bromo-2-pentenyl)-5-chlorotetrahydro-6-(2-penten-4-ynyl)-2//-pyran, see 1-00075... 

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