The bis-aminals obtained by tetraamine and phenylglyoxal condensation display various behaviours such as equilibrium between different configurations, rearrangements that lead to lactam derivatives, or amine deprotection. Our investigations about them were focused on three different linear amines, and then extended to polyazacycloalkanes cyclen and cyclam. Cyclam was also synthesised with the bis-aminals issued from condensation of linear polyamines with phenylglyoxal. The lactam derivatives described here were moreover, employed for the mono-N-functionalisation of tetraamines by phenyl-acetic acid group. © 2003 Elsevier Science Ltd. All rights reserved.