Ricinoleic acid estolides

Bodalo, A., Bastida, J., Maximo, M.F., Montiel, M.C., Gomez, M., Murcia, M.D., 2008. Production of ricinoleic acid estolide with free and Immobilized lipase from Candida rugosa. Biochem. Eng. J. 39,450-456. 

Dehydration of a suitable precursor at high temperature under vacuo initially yielded a polyester (8), upon which pyrolysis afforded the trans-9,trans-11-18 2 isomer. For this procedure ricinoleic acid was first elaidinized, which means a transformation of the ds- double bond into a trans- double bond (9). The so formed ricinelaidic acid was then heated under vacuum at 235°C. Intermolecular esterification (estolide formation) yielded polyesters with a molecular weight of 1500 to 1600. Pyrolysis and simultaneous distillation furnished a crude product, which was recrystallized in 95% ethanol to furnish the desired trans-9,trans-W- % 2 isomer in a 35% yield. 

Figure 3.12 Formation of estolides from ricinoleic acid.

Flydroxycarboxylic acid with the hydroxyl groups at distant carbons in the molecule, such as ricinoleic acid and related hydroxy fatty acids, yield internal esters called estolides upon heating. Estolides have also been found in oxidised Hpids (see Section 3.8.1.14). 

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