Addition of alcoholes to asymmetric epoxides

Summary Formation of some asymmetric glycoles by the addition of some alcoholes or glycoles to the asymmetric epoxides in the presence of HC10₄ were investigated by ¹³C NMR and the results were simply discussed. It was cleared that the formation of the adducts were led by the electronegativity of the side groups as well as steric nature of the nucleophile involved in the reaction is mostly due to the behavior of the oxonium ions formed as intermediates in the reactions.