In ether solution, 1, 3-dioxolanes are hydrogenolyzed faster by LiAlH4-AlCl3 than are the corresponding 1, 3-dioxanes. This difference is attributed to the relative ease of oxocarbonium ion formation in the rate-determining step of the reaction. The results obtained have been utilized to explain the selective cleavage of the five-and six-membered acetal structures found in the polyacetals of hexitols.
