The Grieco elimination is an organic reaction describing the elimination reaction of an aliphatic primary alcohol through a selenide to a terminal alkene [1][2].
The alcohol first reacts with o-nitrophenylselenocyanate and tributylphosphine to a selenide in a nucleophilic substitution on electron deficient selenium. In the second step the selenide is oxidized with hydrogen peroxide to a selenoxide in which elimination takes place with expulsion of a selenol in a fashion similar to that of the Cope elimination. This reaction takes part in the synthesis of ring C of the Danishefsky Taxol synthesis.