Synthesis of 11cis, 15cis- and 10cis, 15cis-Octadecadienoic acid, the probable precursors of 4cis-heptenal in autoxidized butterfat

Research paper by H. J. J. Pabon, D. A. Van Dorp

Indexed on: 01 May '69Published on: 01 May '69Published in: Journal of the American Oil Chemists' Society


11cis,15cis- and 10cis,15cis-Octadecadienoic acid are considered to be precursors of 4cis-heptenal occurring in autoxidized butterfat. The synthesis of these acids was carried out as follows. In liquid ammonia, 1-sodio-1,5-octadiyne was coupled with 1-chloro-9-iodononane and 1-sodio-1,6-nonadiyne with 1-chloro-8-iodooctane. The 1-chloro-10,14-and -9,14-heptadecadiynes thus obtained were converted into 11,15- and 10,15-octadecadiynoic acid. Stereospecific partial hydrogenation of the 11,15-diynoic acid, or of the methyl 10,15-diynoate, and subsequent saponification, yielded the acids desired.