H. Rakoff, E. Emken
Oct 1, 1978
Citations
0
Influential Citations
23
Citations
Journal
Journal of Labelled Compounds and Radiopharmaceuticals
Abstract
Four geometrically isomeric deuterated 12-octadecenoates and their triglycerides were synthesized for use in metabolism studies in humans. Methyl trans-12-octadecenoate-15,15,16,16-d4 (81.7% d4) and the corresponding cis isomer (88.9% d4) were obtained by the Wittig reaction between hexyl-3,3,4,4-d4-triphenylphosphonium bromide (or iodide) and methyl 12-oxododecanoate. The phosphonium salt was derived, in several steps, from 3-hexynol and the methyl 12-oxododecanoate from cyclododecene. Methyl cis-12-octadecenoate-9,10,15,15,16,16-d6 (79.9% d6) was obtained via the Wittig reaction between hexyl-d4-triphenylphosphonium bromide and methyl 12-oxododecanoate-9,10-d2. This deuterated aldehyde ester was prepared by lead tetraacetate oxidation of methyl 12,13-dihydroxyoctadecanoate-9,10-d2 which was obtained, in several steps, from Vernonia anthelmintica seed oil. A simple and convenient stereospecific synthesis of methyl trans-12-octadecenoate-9,10-d2 (84.9% d2) was accomplished by thermal decomposition of methyl 12,13-di-O-(ethoxymethylene)-octadecanoate-9,10-d2 which was prepared, in several steps, from 12,13-epoxy-9-octadecenoate obtained from Vernonia oil. All deuterations were catalyzed by tris(triphenylphosphine)chlororhodium. cis- and trans- isomers were separated on an Amberlyst XN 1005 column impregnated with silver ions.