Butadiene telomers, easily prepared by the palladium-catalyzed telomerization of butadiene with various nucleophiles are extremely useful starting materials for natural product syntheses. The following natural products were synthesized in short steps by using several butadiene telomers : Steroid (19-nortestosterone), macrolides (diplodialides, 9-decanolides, lasiodiplodin, zearalenone, recifeiolide, curvularin), Matsutake alcohol, lipoic acid, pellitorin, dihydrojasmone, methyl dihydrojasmonate, muscone, civetone, pyrethrolone, 12-acetoxy-1, 3-dodecadiene, royal jelly acids and queen substance. In these syntheses, Wacker type oxidation of terminal double bonds to methyl ketones catalyzed by PdCl₂-CuCl is used in key steps.