Huan-Mei Guo

2,6-Bis(2,4-dichloro­benzyl­idene)cyclo­hexa­none

The title compound, C20H14Cl4O, was prepared from a mixture of 2,4-dichlorobenzophenone and cyclohexanone. The dihedral angles formed by the cyclohexane ring and two benzene rings are 39.18 (2) and 60.72 (2)°. There are some weak intramolecular C—H⋯O and C—H⋯Cl hydrogen-bond contacts in the crystal structure.

(3R,6R,12R,20S,24S)-20,24-Ep-oxy-dammarane-3,6,12,25-tetraol dihydrate.

The title compound, C30H52O5·2H2O, was degraded from pseudoginsenoside F11 which was extracted and seperated from Panax quinquefolium saponin. The three six-membered rings are in chair conformations. The five-membered ring is in an envelope conformation and the tetrahydrofuran ring has a conformation intermediate between half-chair and envelope. In the crystal, intermolecular O—H⋯O hydrogen bonds link molecules into a three-dimensional network. Intramolecular O—H⋯O hydrogen bonds also occur.

3-(4-Fluorophenyl)-1,5-diphenyl-2-pyrazoline

Fiveand six-membered heterocyclic compounds are important constituents that often exist in biologically active natural products and synthetic compounds of medicinal interest (Gilchrist, 1998). Among them, 1,3,5-trisubstituted pyrazolines can be easily prepared from phenylhydrazine and chalcone derivatives (Nakamichi et al., 2002). Some 1,3,5-triarylsubstituted pyrazolines can also be used as probes in a biological environment (Fahrni et al., 2003). Here, we report the crystal structure of such a compound, (I).

(3R,6R,12R,20S,24R)-20,24-Ep­oxy­dammarane-3,6,12,25-tetra­ol

In the title compound, C30H52O5, the three six-membered rings are in chair conformations, the five-membered ring is in an envelope form and the tetrahydrofuran ring has a conformation intermediate between half-chair and sofa. Intramolecular O—H⋯O hydrogen bonds may influence the conformation of the molecule. In the crystal, molecules are linked by intermolecular O—H⋯O hydrogen bonds, forming a three-dimensional network.

6-Benzyl 4-ethyl 2-chloro-5,6,7,8-tetra-hydro-pyrido[4,3-d]pyrimidine-4,6-di-carboxyl-ate.

In the title compound, C18H18ClN3O4, the dihedral angle between the pyrimidine ring and the N-bonded ester grouping is 56.27 (7)° and the dihedral angle between the aromatic rings is 11.23 (7)°.

5-tert-Butyl 3-ethyl 1-isopropyl-4,5,6,7-tetra­hydro-1H-pyrazolo­[4,3-c]pyridine-3,5-dicarboxyl­ate

In the title compound, C17H27N3O4, the six-membered ring adopts a half-chair conformation with the N atom and the adjacent methylene C atom displaced by −0.391 (2) and 0.358 (2) Å, respectively, from the plane of the other four atoms. In the crystal, molecules are linked by weak C—H⋯O interactions.

1-[3-(2-Nitro­phen­yl)-5-phenyl-2-pyrazolin-1-yl]ethanone

The title compound, C17H15N3O3, was prepared from 1-(2-nitrophenyl)-3-phenylprop-2-en-1-one and hydrazine. The dihedral angle between the benzene and phenyl rings is 74.55 (2)°. The pyrazoline ring is in a slight envelope conformation with the C atom bonded to the phenyl ring forming the flap. In the crystal structure, weak intermolecular C—H⋯O hydrogen bonds connect molecules into chains along [100].

3-(4-Methoxy­phen­yl)-1-(2-nitrophen­yl)prop-2-en-1-one

The title compound, C16H13NO4, was prepared from 2-nitrylhypnone [systematic name: 1-(2-nitrophenyl)ethanone] and 4-methoxybenzophenone by a Claisen–Schmidt condensation. The dihedral angle formed by the two benzene rings is 80.73 (2). The crystal packing is stabilized by intermolecular C—H⋯O hydrogen bonds.

1-(4-Chloro­phen­yl)-3-(5-methyl-2-fur­yl)prop-2-en-1-one

The title compound, C14H11ClO2, was prepared from 4-chlorohypnone and 5-methylfurfural by an aldol condensation reaction. The dihedral angle formed between the two benzene rings is 7.71 (2)°. The crystal structure is stabilized by C—H⋯O interactions.

3-(5-Methyl-2-fur­yl)-1-(p-tol­yl)-2-propen-1-one

The title compound, C15H14O2, was prepared from 4-methylhypnone and 5-methylfurfural by Clasion–Schmidt condensation. All of the bond lengths and bond angles are in normal ranges. The dihedral angle formed by the benzene ring and furan ring is 5.31 (2).