Chlorine and tertiary alkanol dissolved in an inert organic solvent are reacted with calcium oxide in aqueous calcium chloride to produce tertiary alkyl hypochlorite which is recovered in the organic solvent and reacted with water and olefinically unsaturated compound to produce chlorohydrin and tertiary alkanol. Chlorohydrin and tertiary alkanol recovered in the organic solvent are contacted with calcium oxide in aqueous calcium chloride to produce the epoxy compound, and tertiary alkanol recovered in the organic solvent is recycled to hypochlorite production. Calcium chloride produced as by-product in the hypochlorite production and saponification is recovered as an aqueous solution having a calcium chloride concentration of at least 25 wt. % to provide calcium chloride in a usable form.