This invention provides a catalyst recovery process whereby a liquid/liquid extraction is used to separate mixtures of 2-alkene-1,4-diols and 3-alkene-1,2-diols, formed by the hydration of gamma,delta-epoxyalkenes using mixtures of hydriodic acid and organic solvent soluble iodide salts as catalysts, from the catalyst. In this extraction, gamma,delta-epoxyalkene, or a gamma,delta-epoxyalkene-containing organic solvent, is used to convert any hydriodic acid present to iodoalcohol and to extract the catalysts from water, leaving the diol products in the aqueous phase, from which they may be subsequently recovered by distillation, extraction or by other means.