9-Fluoro-2,4,4a,6-tetrahydrospiro[benzo[c]chromene-3,2′-[1,3]dioxolane]

In the title compound, C15H15FO3, the dihedral angle between the mean plane through all the non-H atoms of the dioxolane ring with those of the rest of the atoms of the chromene ring system, including the substituent F atom, is 81.1 (1)°. The pyran ring has an envelope conformation with the O atom as the flap. The cyclohexene ring has a half-chair conformation, while the dioxolane ring has a twisted conformation on an –O—CH2– bond. In the crystal, molecules are linked via C—H...O hydrogen bonds, forming chains along [100]. The chains are linked by C—H...π interactions, involving the fluorobenzene ring, forming layers parallel to the ac plane

N-Butoxycarbonyl-5-oxo-l-proline ethyl ester

The molecular structure of the title compound, C12H19NO5, may be visualized as made up of two nearly perpendicular planes [dihedral angle = 87.39 (12)°] and its crystal structure is a good example of C—H...O interactions assuming significance in optimizing supramolecular aggregation in crystals in a molecule which is severely imbalanced in terms of donors to acceptor atoms. The pyrrolidine ring adopts a (3T2) twist conformation with puckering parameters Q = 0.2630 (4) Å and ϕ = 59 (9)°. The crystal structure features R24(10) and R34(26) ring motifs formed by four weak C—H...O interactions, leading to supramolecular sheets lying parallel to the bc plane

Crystal structure of 5-benzoyl-2,4-diphenyl-4,5-dihydrofuran-3-carbonitrile

In the title compound, C24H17NO2, the carbonyl O atom of the benzoyl group is cis with respect to the furanyl O atom, and the associated O—C—C—O torsion angle is 4.62 (19)°. The puckering of the dihydrofuran ring is close to twisted (4T5), with parameters Q = 0.1856 (16) Å and φ = 313.5 (5)°. Molecules are interconnected via a C—H...N and a C—H...O hydrogen bond, leading to layers parallel to the (200) plane and characterized by R44(28) and R44(36) graph-set motifs. The furan O atom does not participate in intermolecular hydrogen bonding. The crystal lattice encompasses a solvent-accessible void of 24.7 (8) Å3

2-Amino-4-(4-chlorophenyl)-5,6,7,8,9,10-hexahydrobenzo[8]annulene-1,3-dicarbonitrile

In the title compound, C20H18ClN3, the cyclooctene ring exhibits conformational disorder of two methylene groups with a site-occupation factor of 0.859 (6) for the major occupied site. In the crystal, molecules are connected into inversion dimers via pairs of weak N—H...N hydrogen bonds, forming an R22(12) graph-set motif. These dimers are further connected via weak N—H...Cl interactions into chains running along [011]. There are also C—H...N interactions present in the crystal