PURPOSE: To obtain the subject compound useful as a synthetic intermediate raw material for physiologically active substances such as medicines or agricultural chemicals, functional organic compounds such as liquid crystals or surfactants by oxidizing a compound having epoxy ring at the terminal with an oxidizing agent having protonic acidity.

CONSTITUTION: A compound (preferably 1,2-epoxyalkanes which are optically active substances) having epoxy ring at the terminal is oxidized with an oxidizing agent [preferably nitric acid or the nitric acid containing a small amount of a metal (salt) added thereto] having protonic acidity to afford the objective compound.