title: 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.
abstract: 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).
authors: Chemistry and Biochemistry, University of Arizona, 1306 E. University Blvd, Tucson, AZ 85721, USA.
authors: Sue A
authors: SA
authors: Roberts
authors: Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, AZ 85721, USA.
authors: Guillermo
authors: G
authors: Martinez-Ariza
authors: Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, AZ 85721, USA.
authors: Christopher
authors: C
authors: Hulme
keywords: N—H⋯O hydrogen bonding; butenolides; crystal structure; pharmaceuticals