In the title compound, C(13)H(10)F(3)N(3)O(5), a derivative of andrographolide, the five-membered ring adopts an envelope conformation, while the non-planar six-membered ring has a chair conformation. An intra-molecular C-H⋯F hydrogen bond results in the formation of a non-planar six-membered ring adopting a twisted conformation. In the crystal structure, inter-molecular C-H⋯O hydrogen bonds li...

In the title compound, C(15)H(24)O(4), the six-membered ring shows a distorted chair conformation and the five-membered ring adopts an envelope conformation with the C atom bearing the methyl and OH groups as the flap. In the crystal, O-H⋯O hydrogen bonds link the mol-ecules into chains running along the a-axis direction.

In the title compound, C(12)H(24)O(4), the dioxane ring adopts a chair conformation; the n-hexyl chain, which occupies an equatorial position, has an extended zigzag conformation. In the crystal, mol-ecules are connected by O-H⋯O hydrogen-bonds into a zigzag chain running along the b axis, giving rise to a herringbone pattern.

In the title compound, C(14)H(17)NO(3), the piperidine ring has a chair conformation and an intra-molecular C-H⋯O inter-action stabilizes the mol-ecular conformation. In the crystal, weak inter-molecular C-H⋯O inter-actions occur.

The conformation of the title compound, C(27)H(21)NO(3), is stabilized by a weak intra-molecular C-H⋯O hydrogen bond, which generates an S(6) ring motif. The pyrrolidine ring adopts a half-chair conformation. Both of the other five-membered rings are in envelope conformations. No significant inter-molecular hydrogen bonds are observed.

In the title mol-ecule, C(12)H(18)Cl(2)N(2)O(2), the six-membered ring is in a chair conformation and the five-membered ring is in an envelope conformation. In the crystal, weak inter-molecular bifurcated (C-H)(2)⋯O hydrogen bonds connect mol-ecules into chains along [010].

In the title compound, C(14)H(14)F(4)N(2)O(3)S, the hexa-hydro-pyrimidine ring adopts a half-chair conformation. The mol-ecular conformation is stabilized by an intra-molecular O-H⋯O hydrogen bond, generating an S(6) ring. The crystal structure features O-H⋯S and N-H⋯S hydrogen bonds.

In the title compound, C(28)H(33)NO(4)·CH(2)Cl(2), the pyrrolidone ring adopts a twisted envelope conformation and the cyclo-hexene has a half-chair conformation. In the crystal, weak C-H⋯O hydrogen bonds link the components into chains along [100].

In the title salt, C(6)H(18)N(3) (3+)·3NO(3) (-), the piperazine ring adopts a chair conformation and the ethyl-ammonium group is equatorial relative to the piperazine ring, and in an all-trans conformation. In the crystal, strong charge-assisted N-H⋯O hydrogen bonds link the piperazinediium trications and the nitrate anions into a three-dimensional network.

In the title mol-ecule, C(29)H(28)F(2)N(2)O, the piperazine ring adopts a chair conformation with the pendant N-C bonds in equatorial orientations. The conformation of the N-C-C-O linkage is gauche [torsion angle = -64.6 (4)°] and the dihedral angle between the fluoro-benzene rings is 64.02 (15)°.