A new synthesis of leukotrieneB3 methyl ester is reported, starting from bis(trimethylsilyl) unsaturated derivatives as building blocks for the triene moiety of the leukotriene. The two stereogenic centers have been generated by enantioselective chemical reduction of two acetylenic ketones with both R- or S-Alpine BoraneR. The three conjugated double bonds system of the leukotriene has been assembled