Investigation of Three Diasteromeric Chalcone Epoxides Derivatives by NMR Spectroscopy and X-ray Crystallography

Abstract

Structures of diasteromeric chalcone epoxides derivatives [3-(4-nitrophenyl)oxiran-2-yl)(phenyl)]-methanone (C 15 H 11 NO 4 ), compound 1; (3,4-dimethoxy phenyl)-(3-(4-nitrophenyl)-oxiran-2-yl)methanone (C 17 H 15 NO 6 ) compound 2 and [(3-(4-nitrophenyl)-oxiran-2-yl) phenylmethanol] (C 15 H 13 NO 4 ) compound 3 were established by spectral and X-ray diffraction studies. Compound 1 crystallizes in the monoclinic space group P2 1 /c with unit cell parameters a = 10.3127 (10), b = 10.45331(10), c = 12.9227(13) Å , b = 113.769(2)°, Z = 4. Compound 2 crystallizes in the triclinic space group P-1 with unit cell parameters a = 6.977(1), b = 8.259(1), c = 13.964(2) Å , a = 103.889(2), b = 91.151(2), c = 100.780(2)°, Z = 2. Compound 3 crystallizes in the monoclinic space group P2 1 with unit cell parameters a = 6.708(1), b = 8.388(1), c = 12.407(2) Å , b = 103.322(3)°, Z = 2. The absolute configurations of 3 for the chiral centers are 1S, 2R, and 3R. In structures 1 and 2, the molecules in the crystal are linked by C-HÁÁÁO interactions and van der Waals forces.Molecules 2 in the crystal are stacked in an anti-parallel fashion along the a-axis by pÁÁÁp interactions which gives additional support to molecular packing stability. In structure 3, the molecules in the crystal are linked by both intra-and intermolecular hydrogen bonds O1-HÁÁÁO2 and O1-HÁÁÁO4, respectively. Adjacent molecules are interconnected by intermolecular weak C-HÁÁÁO interactions.

Elucidation of the Structure of the 2-amino-3,5-Dibromochalcone Epoxides in Solution and Solid State

“…This orientation may support the lack of NOE correlation between the αand β-hydrogens observed in the solution-phase geometry. [30,31], although the analogous 1,3-diphenyl-2,3-epoxy-1-propanone has been reported to exist in cis conformation [32]. The quinolyl framework and the p-tolyl ring in the analogous 3-(2-chloro-6-methylquinolin-3-yl)oxiran-2-yl-(p-tolyl)methanone have also been reported to exist in cis configuration with a dihedral angle of 65.80(7)° [33].…”

Synthesis, Identification and Study of the Anti-microbial Activity of Novel Chalcone and Epoxy Chalcone Compounds

“…This ring contraction affects the splitting profile of these protons. In general, all spectra for the epoxy chalcones exhibited a minor J value, which is characteristic of the transstereochemistry (J = 1.9 -2 Hz) of rigid threemembered ring systems (epoxy chalcone) [31][32].…”