Synthesis, structural studies and Hirshfeld surface analysis of the substituted isoindole-1,3‑dione derivatives

In this study, we have performed the ring-opening reaction of 5-benzyl/ethyl-2-hydroxyhexahydro-4H-oxireno[2,3-e] isoindole-4,6(5H)‑dione (10) with HBr to the corresponding bromodiols, regioselectively. Structures of the synthesized compounds are elucidated through spectral methods (1H NMR,13C NMR and HRMS) Afterwards, the racemic products 11a-b were purified and the absolute geometries of 5‑bromo-2-ethyl-4,6-dihydroxyhexahydro-1H-isoindole 1,3(2H)‑dione (11a) and 2-benzyl-5‑bromo-4,6-dihydroxyhexahydro-1H-isoindole-1,3(2H)‑dione (11b) was determined by X-ray diffraction analysis. Effective O−H∙∙∙O (2.738–2.874 Å) hydrogen bonds between diol and ketone units are important interactions between the molecules. Hirshfeld surface analyses of the compounds (11a-b) have provided further insights into molecular, crystal structure and intermolecular interactions. The results indicated that the most important contributions for the crystal packings are from H∙∙∙H, O∙∙∙H/H∙∙∙O, C∙∙∙H/H∙∙∙C and Br∙∙∙H/H∙∙∙Br interactions. Finally, energy frameworks were analyzed to a better understanding of the packing of crystal structure and the supramolecular rearrangements for the structures (11a-b).