(-)-Ascochlorin was synthesized using palladium-catalyzed three component coupling reaction. Reaction of the aryl iodide 3, isoprene, and sodium p-toluenesulfinate in the presence of Pd-2(dba)(3)CHCl3 catalyst and NaHCO3 gave the 4-aryl-2-methyl-2-butenyisulfone 5 selectively in 68% yield. The allylic sulfone 5 was converted into the useful intermediate 2 in 5 steps, which was subjected to Julia olefination with the aldehyde 4 and deprotection gave (-)-ascochlorin.