The reaction of α-(2-pyridylthio)allylstannanes with allylic halides in the presence of a catalytic amount of copper(I) iodide in DMSO-THF produced the 1,5-dienes 3 in good yields. The γ-selective allylation using allyl chloride followed by the alkylation and hydrolysis of resulting vinyl sulfides gave δ,ε-unsaturated ketones.