monoaldehyde in the form of the internal acetal 2-hydroxy-1,4-dioxane. This compound was used in reductivealkylations of selected primary and secondary amines, demonstrating its utility in the preparation of target structures with the 2-(2-hydroxyethoxy)ethylamino unit. diethylene glycol - oxidations - reductivealkylations - 2-hydroxy-1,4-dioxane - ruthenium(VIII) catalysis