RESUMEN
The crystal structures and packing features of two homologous Meyer's bicyclic lactams with fused pyrrolidone and medium-sized perhydropyrimidine rings, namely, 8a-phenyl-2,3,4,7,8,8a-hexahydropyrrolo[1,2-a]pyrimidin-6(1H)-one, C13H16N2O (1), and 8a-(4-methylphenyl)-2,3,4,7,8,8a-hexahydropyrrolo[1,2-a]pyrimidin-6(1H)-one, C14H18N2O (2), were elucidated, and Hirshfeld surface plots were calculated and drawn for visualization and a deeper analysis of the intermolecular noncovalent interactions. Molecules of 1 and 2 are weakly linked by intermolecular C=O...H-N hydrogen bonds into chains, which are in turn weakly linked by other C=O...H-Car interactions. The steric volume of the substituent significantly affects the crystal packing pattern.
RESUMEN
In the title compound, C12H13NO2, the pyrrolidinone moiety is almost flat while the oxazole ring adopts an envelope conformation with the carbon atom bearing the phenyl substituent as the flap: the angle between the mean planes of the fused heterocyclic rings is 45.47â (19)°. In the crystal, C-Hâ¯O and C-Hâ¯π contacts link the mol-ecules into infinite [010] chains.