The successive treatment of (E)-delta-(arylmethoxy)-substituted allylic sulfones with t-BuOK and LDA afforded the corresponding (Z)-2,4-dienyl alcohols with high stereoselectivities via 1,4-elimination and the [1,2]-Wittig rearrangement. The predominant formation of (Z)-isomers, due to "syn-effect" in the elimination step, was further successfully applied to (E)-delta-(3-silyl-2-propynyloxy)-substituted allylic sulfones.