Although a literature search revealed no examples of reduction of an acylguanidine with lithium aluminum hydride (LiAlHd), a statement'that the guanidine group is inert to LiAlH4 suggested to us that the reduction of an acylguanidine to an alkylguanidine might be possible. The utility of such a conversion is illustrated by the occurrence of the alkylguanidine moiety in a wide variety of biological systems and the presence of the ...