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-4 H -oxireno[2,3-e] isoindole-4,6(5 H )‑dione ( 10 ) with HBr to the corresponding bromodiols, regioselectively. Structures of the synthesized compounds are elucidated through spectral methods ( 1 H NMR, 13 C NMR and HRMS) Afterwards, the racemic products 11a-b were purified and the absolute geometries of 5‑bromo-2-ethyl-4,6-dihydroxyhexahydro-1 H -isoindole 1,3(2 H )‑dione ( 11a ) and 2-benzyl-5‑bromo-4,6-dihydroxyhexahydro-1 H -isoindole-1,3(2 H )‑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).