ANOMALOUS RING CLEAVAGE DURING LITHIUM ALUMINUM HYDRIDE – ALUMINUM CHLORIDE REDUCTION OF 2,2,4,4-TETRAALKYLATED-1,3-DIOXOLANES

Abstract

The anomalous reductive cleavage by LiAlH4–AlCl3 of 2,2,4,4-tetramethyl-1,3-dioxolane in ether solution has been examined. Evidence supports the view that this unexpected direction of ring cleavage is due to steric repression of the formation of the intermediate oxocarbonium leading to cleavage of the C2—O1 bond of the dioxolane ring.