Crystal structure of 3,6-dihydroxy-4,5-dimethylbenzene-1,2-dicarbaldehyde

Abstract

The planar achiral title compound has C 2v symmetry and crystallizes in the chiral space group P21.

(Z)-1-Benzoyl-5-benzylidene-2-hydroxy-4-oxo-4,5-dihydro-1H-pyrrole-3-carbonitrile

“…Narasegowda et al (2005) reported a case of chiral crystallization in space group P2 1 2 1 2 1 , the same space group as the title compound. In contrast, our recent examples of chiral crystals composed of achiral molecules both crystallize in space group P2 1 (Yagi et al, 2018;Yamazaki et al, 2018). To the best of our knowledge, this is the first crystal structure reported for chiral crystallization of a pyrrole of this type.…”

Hirshfeld Surface Analysis for Investigation of Intermolecular Interaction of Molecular Crystals

“…This is an achiral, neutral, and almost simple planar compound that interestingly crystallizes in a space group without centrosymmetry (sometimes called "chiral crystallization") [66]. Between these planar molecules, some localized O•••H interactions (five types were pointed out in the original paper) can be identified by…”

Success or Failure of Chiral Crystallization of Similar Heterocyclic Compounds

“…In this study, chiral crystallization (achiral compounds crystallize in the chiral space group) [20][21][22] was observed in a heterocyclic 4-hydroxycoumarin compound (CA1), accidentally obtained in trying to synthesize a hydrazone Schiff base ligand, by reacting 4-hydroxycoumarin and pyrazinamide in the presence of glacial acetic acid in ethanolic solution. However, chiral crystallization was not observed in a heterocyclic compound (CA4), accidentally obtained in trying to synthesize a Schiff base ligand, by reacting isatin and pyrazinamide in the same procedure as for CA1.…”