A series of cis and trans 3, 7-diazabicyclo [4.3. 0] nonan-8-ones has been synthesized and tested for their ability to revert scopolamine-induced amnesia in the mouse passive- avoidance test. The racemates of the most potent compounds 4 and 7 were separated and tested, but no enantioselectivity was found for the nootropic activity. Compounds 4 and 7 and their enantiomers displayed interesting antihyperalgesic activity in two models of ...