Under mild conditions, trialkylalanes (Et3Al and (Bu3Al)-Al-i) in chlorine-containing solvents (CH2Cl2 or ClCH2CH2Cl) react with cyclic acetals and orthoformates to form glycol monoethers and dialkylacetals, respectively, in high yields. The H-1 NMR spectroscopic data demonstrate that CH2Cl2 or ClCH2CH2Cl interacts with (Bu3Al)-Al-i.