data reports
Open access
In the title compound, C17H15NO4, the conformation about the C=C double bond [1.348 (2) Å] is E with the ketone group almost co-planar [C—C—C—C torsion angle = 7.2 (2)°] but the phenyl group twisted away [C—C—C—C = 160.93 (17)°]. The terminal aromatic rings are almost perpendicular to each other [dihedral angle = 81.61 (9)°] giving the molecule an overall U-shape. The crystal packing feature benzene-C—HO(ketone) contacts that lead to supramolecular helical chains along the b axis. These are connected by π–π interactions between benzene and phenyl rings [inter-centroid distance = 3.6648 (14) Å], resulting in the formation of a supramolecular layer in the bc plane.
data reports
Open access
In the title compound, C15H20BrNO2, there are two independent molecules (A and B) comprising the asymmetric unit and these adopt very similar conformations. In A, the dihedral angle between the CO2 and MeC=CMe2 groups is 80.7 (3)°, and these make dihedral angles of 3.5 (3) and 84.09 (16)°, respectively, with the bromobenzene ring. The equivalent dihedral angles for molecule B are 78.4 (3), 2.1 (3) and 78.37 (12)°, respectively. The most prominent interactions in the crystal packing are amine-N—HO(carbonyl) hydrogen bonds between the two independent molecules, resulting in non-centrosymmetric ten-membered {OC2NH}2 synthons. Statistical disorder is noted for each of the terminal methyl groups of the ethyl residues.