N-Monoalkyl 1, 5-diaza-cis-decalins were synthesized in high yield and purity by derivatization of tetrahydronaphthyridine followed by reduction to the saturated system. The position of the conformational equilibrium between the chair–chair inversion forms of a series of four N-monoalkyl of 1, 5-diaza-cis-decalins was measured and was directly related to the size of the N-alkyl group.
