rac-Ethyl 2-hy-droxy-2,7,7-trimethyl-4-(4-nitro-phen-yl)-5-oxo-3,4,5,6,7,8-hexa-hydro-2H-chromene-3-carboxyl-ate.

The title mol-ecule, C21H25NO7, has four stereogenic centres and crystallized as a racemate. It consists of enanti-omeric pairs with the relative configuration rac-(1R*,2S*,3R*). The cyclo-hexenone ring adopts an envelope conformation; the dimethyl-substituted C atom lies 0.640 (1) Šout of the mean plane formed by the rest of the ring atoms (r.m.s. deviation = 0.016 Å). The oxacyclo-hexene ring adopts a half-chair conformation, the hy-droxy- and carboxyl-substituted C atoms lying -0.336 (1) and 0.419 (1) Å, respectively, out of the mean plane formed by the rest of the ring atoms (r.m.s. deviation = 0.002 Å). In the crystal, O-H⋯O hydrogen bonds link the mol-ecules into a chain along the c-axis direction.

1,10-Bis[2-(prop-1-en-yl)phen-oxy]deca-ne.

The complete molecule of the title compound, C(28)H(38)O(2), is generated by a crystallographic centre of symmetry. The molecular conformation displays an intra-molecular C-H⋯π inter-action.

rac-2-tert-Butyl-2,4,5,6,6-penta-chloro-cyclo-hex-3-en-1-one.

The title compound, C(10)H(11)Cl(5)O, is a chiral mol-ecule with two stereogenic centres. However, it crystallizes as a racemate. One of enanti-omers reveals the relative configuration (2S*,5R*). The cyclo-hexene ring adopts a half-chair conformation.

rac-5-Acetyl-6-hy-droxy-3,6-dimethyl-4-phenyl-4,5,6,7-tetra-hydro-2H-indazole.

The title compound, C(17)H(20)N(2)O(2), is chiral but crystallizes in a centrosymmetric space group as a racemate, the relative configuration at the stereogenic centres being 2S*,3R*,4S*. The cyclo-hexane ring adopts a half-chair conformation while the pyrazole ring has an envelope conformation. The crystal packing displays inter-molecular O-H⋯N and N-H⋯O hydrogen bonding.

Poly[(µ(3)-rac-5-eth-oxy-carbonyl-6-hy-droxy-6-methyl-4-phenyl-4,5,6,7-tetra-hydro-benzo[c]isoxazol-3-olato)potassium].

The title compound, [K(C(17)H(18)NO(5))](n), reveals the relative configuration (4R*,5S*,6R*) whereas its crystals are racemic. The cyclo-hexane ring adopts a half-chair conformation and the isoxazole ring has an envelope conformation. The ethyl fragment of the eth-oxy-carbonyl group at position 5 is disordered in a 0.547 (7):0.453 (7) ratio. The K(+) ion is surrounded by five O atoms from three ligands at distances ranging from 2.606 (2) to 3.028 (2) Å, generating a three-dimensional network. The crystal packing displays inter-molecular O-H⋯N and O-H⋯O hydrogen bonds in which the hy-droxy group acts as a double proton donor.

rac-Diethyl 9-hy-droxy-9-methyl-7-phenyl-1,4-diaza-spiro-[4.5]decane-6,8-dicarboxyl-ate.

The title mol-ecule, C(21)H(30)N(2)O(5), is chiral with four stereogenic centres. The crystal is a racemate and consists of enanti-omeric pairs with the relative configuration rac-(6S*,7R*,8R*,9S*). The ethyl fragment of the eth-oxy-carbonyl group at position 6 is disordered in a 0.46 (3):0.54 (3) ratio. The crystal structure features inter-molecular N-H⋯O. Intra-molecular O-H⋯N and N-H⋯O hydrogen bonds also occur.

Ethyl 3,6-dihy-droxy-6-methyl-4-phenyl-4,5,6,7-tetra-hydro-1H-indazole-5-carboxyl-ate monohydrate.

In the title compound, C(17)H(20)N(2)O(4)·H(2)O, the cyclo-hexene ring adopts a half-chair conformation while the indazole ring is essentially planar [maximum deviation = 0.0192 (12) Å]. In the crystal, pairs of inter-molecular O-H⋯N hydrogen bonds link the mol-ecules into dimers lying about inversion centers and intra-molecular O-H⋯O hydrogen bonds result in six-membered rings. The dimers are further connected by N-H⋯O and O-H⋯O hydrogen bonds.

rac-Ethyl 6-hy-droxy-6-methyl-3-oxo-4-phenyl-1,3,4,5,6,7-hexa-hydro-benzo[c][1,2]oxazole-5-carboxyl-ate.

In the title compound, C(17)H(19)NO(5), the cyclo-hexene ring is in a half-chair conformation and the isoxazole ring in an envelope conformation with the N atom as the flap. The C atoms in the 4- and 6-positions are of the same absolute configuration, whereas the C atom in the 5-position is of the opposite configuration, i.e. (4S*,5R*,6S*). The methyl fragment of the eth-oxy-carbonyl group at position 5 is disordered over two sets of sites in a 0.60:0.40 ratio. The crystal packing displays inter-molecular N-H⋯O and O-H⋯O hydrogen bonds.

rac-5-Acetyl-6-hy-droxy-3,6-dimethyl-4-phenyl-2H-4,5,6,7-tetra-hydro-indazol-1-ium chloride.

The structure of the title compound, C(17)H(21)N(2)O(2) (+)·Cl(-), is of inter-est with respect to its biological activity. The title compound comprises an organic cation and a chloride anion in the asymmetric unit. The positive charge is localized in a pyrazole moiety forming a pyrazolium cation. The structure displays inter-molecular O-H⋯Cl and N-H⋯Cl hydrogen bonding.

rac-(1R*,2S*,3S*)-Diethyl 4-methyl-2-phenyl-6-(2-phenyl-hydrazinyl-idene)cyclo-hex-4-ene-1,3-dicarboxyl-ate.

In the title compound, C(25)H(28)N(2)O(4), the cyclohexene ring adopts a half-chair conformation and the dihedral angle between the aromatic rings is 59.44 (11)°. In the crystal, a weak intermolecular N-H⋯O hydrogen bond occurs.

rac-Diethyl 6-hy-droxy-4-[(2-hy-droxy-eth-yl)amino]-6-methyl-2-phenyl-cyclo-hex-3-ene-1,3-dicarboxyl-ate.

The title compound, C(21)H(29)NO(6), is chiral with three stereogenic centres. The crystal is a racemate and consists of enanti-omeric pairs with the relative configuration rac-(2R*,3S*,4R*). The ethyl fragment of the eth-oxy-carbonyl group at position 1 is disordered in a 0.60:0.40 ratio. The crystal packing displays inter-molecular O-H⋯O hydrogen bonding. An intra-molecular N-H⋯O hydrogen bond also occurs.

rac-1-(6-Hy-droxy-3,6-dimethyl-4-phenyl-4,5,6,7-tetra-hydro-2,1-benzoxazol-5-yl)ethanone.

The structure of the title compound, C(17)H(19)NO(3), is of inter-est with respect to anti-bacterial properties, anti-biotic properties and biological activity. The structure displays inter-molecular O-H⋯N hydrogen bonding.