(5Z,8Z,11Z,14Z)-Ethyl 17-Oxoheptadeca-5,8,11,14-tetranoate is an intermediate used in the synthesis of Eicosapentaenoic Acid (E477802), which is an important polyunsaturated fatty acid of the marine food chain that serves as a precursor for the prostaglandin-3 and thromboxane-3 families. Also, it differs from arachidonic acid (the eicosatetraenoic acid that is a precursor for the prostaglandin and thromboxane-2 families) by the extra double bond between the third and fourth carbons from the “methyl end” of the molecule. Antilipemic.