The mol-ecular structure of the title compound, C10H12O4, contains an intra-molecular hydrogen bond between the phenol and acetyl substituents. In the crystal, C-H⋯π inter-actions act between the mol-ecules in a cyclic manner to stabilize stacks of mol-ecules along the b axis. Several C-H⋯O inter-actions are present between the stacks.

The title compound, C(12)H(16)ClNO(2)S, adopts an L-shaped conformation, with the central C-S-N-C torsion angle being -78.0 (2)°. The cyclo-hexyl ring adopts a chair conformation. In the crystal, adjacent mol-ecules are connected by pairs of N-H⋯O hydrogen bonds around an inversion centre, forming cyclic dimers [graph set R(2) (2)(8)].

In the title compound, C(28)H(50)O(5)·H(2)O, all of the six-membered rings of the penta-cyclic triterpene skeleton adopt chair conformations. In the crystal, mol-ecules are linked by O-H⋯O and C-H⋯O hydrogen bonds.

In the title compound, C(5)H(5)ClN(2), a by-product in the synthesis of ethyl 2-(3-chloro-pyridin-2-yl)-5-oxopyrazolidine-3-carboxyl-ate, the amine groups form inter-molecular hydrogen-bonding associations with pyridine N-atom acceptors, giving centrosymmetric cyclic dimers. Short inter-molecular Cl⋯Cl inter-actions [3.278 (3) Å] also occur.

In the title compound, C(15)H(18)ClNO(2), the amide group is coplanar with the chloro-phenyl group, making a dihedral angle of 1.71 (12)°. The cyclo-penta-none ring adopts a twist conformation. A weak intra-molecular C-H⋯O hydrogen bond is observed. Mol-ecules are linked into cyclic centrosymmetric dimers by paired N-H⋯O hydrogen bonds.

The title compound, C(8)H(7)BrO, is a halogenated derivative of acetophenone. The mol-ecule shows noncrystallographic C(s) symmetry. The intra-cyclic C-C-C angles cover the range 118.8 (2)-120.4 (3)°. In the crystal structure, C-H⋯O contacts connect the mol-ecules into undulating sheets perpendicular to the crystallographic c axis.

In the asymmetric unit of the title compound, C(19)H(17)NO(3), there are two crystallographically independent mol-ecules, which are connected to each other by O-H⋯O hydrogen bonds, forming mol-ecular chains as well as cyclic centrosymmetric R(2) (2)(16) dimers.

Through selective cultivation with 6-aminohexanoate linear dimer, a by-product of nylon-6 manufacture, as the sole source of carbon and nitrogen, Pseudomonas aeruginosa PAO, which initially has no enzyme activity to degrade this xenobiotic compound, was successfully expanded in its metabolic ability. Two new enzyme activities, 6-aminohexanoate cyclic dimer hydrolase and 6-aminohexanoate dimer h...

The title compound, C(11)H(14)O(3), is a multiple-substituted derivative of benzoic acid. Intra-cyclic C-C-C angles span a range of 117.16 (19)-122.32 (19)°. Apart from intra-molecular hydrogen bonds between hydroxyl and carboxyl groups, inter-molecular hydrogen bonds are present in the crystal structure, the latter ones giving rise to centrosymmetric carb-oxy-lic acid dimers.

The title compound, C(31)H(50)O, a tetra-cyclic triterpene, was isolated from Ainsliaea henryi. The mol-ecule contains a three-membered ring, a five-membered ring, which exhibits an envelope conformation, and three six-membered rings, which adopt chair conformations.