Roberts, S. A., Martinez-Ariza, G., & Hulme, C. (2015). Crystal structures of N-tert-butyl-3-(4-fluoro-phenyl)-5-oxo-4-[2-(tri-fluoro-meth-oxy)phen-yl]-2,5-di-hydro-furan-2-carboxamide and 4-(2H-1,3-benzodioxol-5-yl)-N-cyclo-hexyl-5-oxo-3-[4-(tri-fluoro-meth-yl)phen-yl]-2,5-di-hydro-furan-2-carboxamide. Acta crystallographica. Section E, Crystallographic communications, 71(Pt 2), 199-202.
The title compounds, C22H19F4NO4, (I), and C25H22F3NO5, (II), each contain a central nearly planar di-hydro-furan-one ring. The r.m.s. deviation from planarity of these rings is 0.015 Å in (I) and 0.027 Å in (II). The mol-ecules are T-shaped, with the major conformational difference being the O-C-C-O torsion angle [-178.9 (1) in (I) and 37.7 (2)° in (II)]. In the crystal of (I), mol-ecules are linked by N-H⋯O hydrogen bonds, forming chains along [001] while in (II) mol-ecules are linked by N-H⋯O hydrogen bonds, forming chains along [010]. In (II), the tri-fluoro-methyl substituent is disordered over two sets of sites, with refined occupancies of 0.751 (3) and 0.249 (3).