A new series of analogues (1c–j; 2c–i) of the previously reported analgesic 3, 8-diazabicyclo [3.2. l] octanes (1a, b; 2a, b) was synthesized and tested for their affinity towards μ-opioid receptors. Modifications were introduced either at the cinnamyl or the acyl side chains. The majority of the new compounds, with the exception of 1c, j and 2c, showed Ki values better or comparable with those of the models.