Abstract Reactive organometallic compounds such as allyl-zinc,-magnesium, and-lithium and saturated lithium compounds are shown to bring about readily an addition reaction with simple and α-substituted conjugated enynes R C C CH CH CH 2 R′[R= H, CH 3; R′= alkyl, OH, OC 4 H 9, NHC 2 H 5, N (C 2 H 5) 2].