The synthesis of substituted dioxolanes by direct oxidation of olefins over a molybdenum 8-hydroxyquinoline catalyst in the presence of water is described. An organic solvent such as chlorobenzene may also be employed. Water is essential to the reaction to make the dioxolanes, otherwise olefin oxides are produced. Hence, 4-methyl-1,3-dioxolane and 2,4-dimethyl-1,3-dioxolane were prepared from propylene oxidation, and three isomers of 2,4,5-trimethyl-1,3-dioxolane were prepared from 2-butene oxidation.