In the title compound, C 23H 26O 4, the two cyclo-hexene rings adopt envelope conformations whereas the pyran ring adopts a boat conformation. In the crystal, pairs of inter-molecular O - H⋯O hydrogen bonds link the molecules into inversion dimers.

Sarveswari S

Department of Chemistry

School of Advanced Sciences

Vellore Campus

Vijayakumar V

Fun H.-K

Loh W.-S

Rajesh K

Fulltext

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

&nbsp;

&nbsp;

VIT University

9-(4-Hy-droxy-phen-yl)-3,3,6,6-tetra-methyl-4,5,6,9-tetra-hydro-3H-xanthene-1,8(2H,7H)-dione.

Acta Crystallographica Section E Structure Reports Online

The 1,4-dihydro-pyridine ring in the title compound, C17H 19NO5, has a flattened-boat conformation, and the benzene ring is almost orthogonal to it [dihedral angle = 82.98 (12)°]. The hydr-oxy group is disordered over two positions in a 0.780 (4):0.220 (4) ratio. In the crystal, hydrogen-bonding inter-actions of the type Na - H⋯Oc and Oh - H⋯Oc (a = amine, c = carbonyl and h = hydr-oxy) link the mol-ecules into a three-dimensional network.

Dimethyl 4-(3-hydroxyphenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate

The 1,4-dihydro-pyridine ring in the title hydrate, C17H 18BrNO2·H2O, has a flattened-boat conformation, and the benzene ring is occupies a position orthogonal to this [dihedral angle: 82.19 (16)°]. In the crystal packing, supra-molecular arrays mediated by N - H⋯Owater and Owater - H⋯Ocarbonyl hydrogen bonding are formed in the bc plane. A highly disordered solvent mol-ecule is present within a mol-ecular cavity defined by the organic and water mol-ecules. Its contribution to the electron density was removed from the observed data in the final cycles of refinement and the formula, mol-ecular weight and density are given without taking into account the contribution of the solvent mol-ecule.

1-[5-Acetyl-4-(4-bromophenyl)-2,6-dimethyl-1,4-dihydropyridin-3-yl]ethanone monohydrate

In the mol-ecular structure of the title compound, C21H 25NO4, the dihydro-pyridine ring adopts a flattened boat conformation while the cyclo-hexenone ring is in an envelope conformation. In the crystal structure, mol-ecules are linked into a two-dimensional network parallel to (10 ) by N- H⋯O and O- H⋯O hydrogen bonds. The network is generated by R 4 4(30) and R 4 4(34) graph-set motifs.

Ethyl 4-(3-hydroxyphenyl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate

Examination of the symmetric Hantzsch 1,4-dihydropyridine ester derivatives of the prototypical nifedipine molecule indicates the tendency of this class of molecule to form a common packing motif. Crystal structure analysis of 2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylic diesters and analogs reveals that they form extended chains, characterized as the C(6) packing motif, via intermolecular (amine) N—H...O=C (C3,C5 carbonyl) hydrogen bonds. In addition, all the prepared derivatives also satisfy the basic structural requirements for their high binding efficiency to the receptor. The reproducible C (6) packing motif observed among these compounds has a use in the design of solid-state materials.

Journal	Acta Crystallographica Section E Structure Reports Online
Publisher	International Union of Crystallography (IUCr)
ISSN	16005368
Open Access	No