SYNTHESIS OF (2,3-C-13(2)) ERUCIC-ACID

The synthesis of (2,3-C-13(2)) erucic acid, for use in metabolic studies, is reported. The synthesis employs a repeated 3 step reaction sequence using C-13 labeled triethylphosphonoacetate to extend C18:1, oleyl alcohol, by 4 carbons. The starting alcohol is first oxidized with PCC and the resulting aldehyde is condensed with triethyl( 1-C-13)phosphonoacetate. The product, an alpha,beta unsaturated ester, is reduced with (Ph3PCuH), to ethyl eicosenoate. Reduction with LAH gives eicosenoyl alcohol. A repetition of the reaction sequence using triethyl(2-C-13) phosphonoacetate results in ethyl(2,3-C-13(2))erucate. The (2,3-C-13(2)) erucic acid, obtained by hydrolysis with alcoholic KOH, gave C-13 NMR signals of delta 24.6 and 34.1 ppm for C-3 and C-2 respectively with a J = 34.9 Hz.The overall yield was 5.5 %.