In the title compound, C(18)H(20)BrNO(3), the oxazolidine ring adopts an envelope conformation with the N atom at the flap position. The mean plane of oxazolidine ring makes dihedral angles of 82.96 (13) and 70.97 (12)°, respectively, with the phenyl and benzene rings. In the crystal, adjacent mol-ecules are connected via O-H⋯O and C-H⋯O hydrogen bonds and C-H⋯π inter-actions into a zigzag chai...

In the title compound, C(28)H(27)ClN(2)O(3)S, the central imidazolidine ring adopts an envelope conformation with the C atom bearing the chloro-phenyl ring at the flap. The geometry around the S atom is distorted tetra-hedral. Three methyl-ene groups of the cyclo-hexene ring are disordered over two sets of sites [site occupancies = 0.562 (10) and 0.438 (10)]. The crystal packing is stabilized b...

The title ester, C27H30N2O3, crystallizes with two independent mol-ecules in the asymmetric unit whose geometrical features are similar. In each mol-ecule, the pyrrolidine ring adopts an envelope conformation, with the fused C atom shared with the piperidine ring as the flap, and the piperidine ring adopts a chair conformation. In the crystal, C-H⋯π inter-actions link the inversion-related mole...

The title compound, C(28)H(34)Cl(2)O(7), is a derivative of the glucocorticoid steroid beclomethasone dipropionate. It features an expoxide linkage [angle at oxygen = 96.6 (2)°]. The dichlorocyclohexenone ring adopts an envelope conformation, with the C atom bearing the two Cl substituents representing the flap. The dichloro-methyl C atom deviates by 0.471 (4) Å from the plane defined by the ot...

In the title compound, C(23)H(24)O(8)·H(2)O, the six-membered ring of the oxan-4-one (tetra-hydro-pyran-4-one) ring displays an envelope conformation with the heterocyclic O atom at the flap position. The dihedral angles between the terminal benzene rings is 37.23 (10)°. Classical intermolecular O-H⋯O and weak C-H⋯O hydrogen bonds are present in the crystal structure.

In the title compound, C17H16O7, which was isolated from the leaves of Micromelum integerrimum, the furan ring adopts an envelope conformation with the O atom as the flap. An intra-molecular C-H⋯O hydrogen bond occurs. The carbonyl O atom is disordered in a 0.57 (8):0.43 (8) ratio. In the crystal, mol-ecules are linked by weak C-H⋯O hydrogen bonds into a C(10) chain along [010].

In the title compound, C20H18ClN3O3, the five- and six-membered heterocycles fused through a spiro C atom are inclined to each other at an angle of 87.4 (1)°. In the tricyclic ring system, the cyclo-hexene ring adopts an envelope conformation with the spiro atom as the flap. In the crystal, two sets of N-H⋯O hydrogen bonds link the mol-ecules into columns containing centrosymmetric R 2 (2)(7) r...

In the title compound, C(11)H(12)O(2), the six-membered ketone ring fused to the 7-meth-oxy benzene ring adopts a slightly distorted envelope configuration with the central methyl-ene C atom being the flap. The crystal packing is stabilized by weak inter-molecular C-H⋯O and C-H⋯π inter-actions, which lead to supra-molecular layers in the bc plane.

The title compound, C(20)H(20)N(2)O, was synthesized by a solvent-free one-pot three-component domino reaction of naph-tha-len-2-ol, nicotinaldehyde and pyrrolidine. The dihedral angle between the naphthalene ring system and the pyridine ring is 74.22 (6)°. The pyrrolidine ring assumes an envelope conformation with the N atom as the flap. An intra-molecular O-H⋯N hydrogen bond stabilizes the mo...

In the title compound, C22H25ClN2O, the pyrazole ring exhibits an envelope conformation with the methine C atom as the flap. The benzene rings are twisted by 3.3 (5) and 84.6 (5)° from the pyrazole mean plane, and are inclined to each other by 81.4 (4)°. In the crystal, pairs of weak C-H⋯O hydrogen bonds form centrosymmetric dimers with an R 2 (2)(16) graph-set motif. C-H⋯π inter-actions link t...