One-step and non-catalytic intramolecular redox reactions of conjugated all E-dienals to non-conjugated Z-enoic acids in subcritical water

► Non-conjugated unsaturated acid derivatives are obtained by treating conjugated dienals in superheated fluids in one-step. ► Simple treatment of all E-dienals in superheated fluids produces thermodynamically less-stable Z unsaturated acid derivatives. ► The obtained non-conjugated unsaturated acid is converted to biologically active γ-lactone with a hydroxyl group by hydrogen peroxide in one step.