In the search for biological agents, a series of new N-substituted ethyl 11-ethyl-7-methyl-3,5,10-trioxo-4-azatricyclo[5.2.2.02,6]undecane-8-carboxylates 3, 9-methyl-3,5,8-trioxo-4-azatricyclo[5.2.1.02,6]dec-1-yl acetates 6 and 1,3-dioxo-4,5,6,7-tetraphenyl-2,3,3a,4,5,7a-hexahydro-1H-isoindole-4-carboxylic acids 9 were prepared. All compounds were characterized by 1H NMR, ESI-MS, and elemental analyses. Moreover, for intermediate products 2, 5, and 8, X-ray structural analyses were conducted. Compounds 3a–e, 6a, 6b, 9a–e were tested for their cytotoxic properties in K562 and HeLa cells.