A series of 1, 3-dialkyl-2-imidazolidinones 1 and 1, 3-dialkyltetrahydro-2 (lH)-pyrimidinones 2 were reduced to the corresponding aminals 3 and 4, respectively, when treated with excess lithium aluminum hydride in ether. The rate of reduction is affected dramatically by the alkyl substituents and slightly by ring size. Although lithium aluminum hydride reduces cyclic ureas under relatively mild conditions, reduction of ureas occurs less readily than ...
