LARGE-SCALE SYNTHESIS OF METHYL CIS-9,TRANS-11-OCTADECADIENOATE FROM METHYL RICINOLEATE

The conjugated linoleic acid methyl cis-9, trans-11-octadecadienoate h as been prepared on a large scale from methyl ricinoleate. Methyl rici noleate was purified from castor esters by a partition method. It was converted to the mesylate, which was reacted with a base (1,8-diazabic yclo[5.4.0]-undec-7-ene) to give a product that contained 66% of the d esired ester; Two urea crystallizations produced a product containing 83% methyl cis-9, trans-11-octadecadienoate, the identity of which was confirmed by gas chromatography linked to mass spectrometry and by Fo urier transform infrared spectroscopy. The remaining impurities were m ethyl cis-9, cis-11- and cis-9-, trans-12-octadecadienoate.