Abstract Trienes of the type R (R′) C [DOUBLE BOND] C [DOUBLE BOND] C [DOUBLE BOND] CH 2 (R and R′ are H or alkyl) have been prepared in good to excellent yields from 1, 4-dichloro-2-alkynes, R (R′) C (Cl) C [TRIPLE BOND] CCH 2 Cl, and zinc dust or sodium iodide in dimethyl sulfoxide.