Abstract: Leukotriene E4 and two analogues homo-LTE4 and nor-LTE4 have been prepared via the intermediate epoxides. The epoxides were formed by the coupling of a polyenyne sulfonium salt with the required aldehyde-ester in a biphasic reaction system employing aqueous sodium hydroxide as the base for the generation of the ylide. Reduction of the acetylene bonds yielded the desired polyene epoxides which on treatment with L-cysteine ...