Total synthesis of (5Z,8Z,11Z,14Z)-18- and 19-oxoeicosa-5,8,11,14-tetraenoic acids

18-oxo-ETE was synthesized via the corresponding tetraacetylenic precursor, which was prepared by cross-coupling of three key synthons: methyl 5-hexynoate, the bisfunctional C7–C13 fragment—7-bromo-2,5-heptadiyne-1-ol and rac-3-(benzoyloxy)hept-6-yn. The carbonyl function was introduced at the last synthesis step. 19-oxo-ETE was synthesized by coupling of acid anhydride, prepared from monomethyl ester of (5Z,8Z,11Z,14Z)-nonadeca-5,8,11,14-tetraen-1,19-dioic acid, either with lithium dimethylcuprate or methylcuprate in a one-step procedure.