Synthesis of 11,12-leukotriene A4, 11S,12S-oxido-5Z,7E,9E,14Z-eicosatetraenoic acid, a novel leukotriene of the 12-lipoxygenase pathway

A simple and efficient method for preparing 11,12-leukotriene A4 has been established by the stereospecific biomimetic route from arachidonic acid. 12S-Hydroperoxy-5Z,8Z,10E,14Z-eicosatetraenoic acid was synthesized using a partially purified 12-lipoxygenase of porcine leukocytes. The methyl ester of the compound was then chemically converted to two labile epoxides with a conjugated triene structure. These compounds were identified by proton NMR and mass spectrometry to be 11S,12S-oxido-5Z,7E,9E,14Z-eicosatetraenoic acid (11,12-leukotriene A4) and its geometric isomer.