Secohellebrigeninamide

The title compound, C₂₆H₃₇NO₅, was the reaction product of hellebrigenin with N,N-dimethyl­formamide. It consists of three cyclo­hexane rings (A, B and C), one five-membered ring (D) and one dihydro­pyran ring (E). The stereochemistry of the ring junctions is is A/B cis, B/C trans, C/D cis and C/E trans. The cyclo­hexane rings A, B and C have chair conformations. Both the five-membered ring D and the dihydro­pyran ring adopt an envelope conformation. Two orientations are found for the aldehyde group with occupancies of 0.608 (10) and 0.392 (10). In the crystal, short O—H...O hydrogen bonds and short C—H...O contacts involving the hy­droxy group, terminal methyl group and carbonyl group link the mol­ecules into a three-dimensional network.

2,3,4-Trihy­droxy­benzoic acid 0.25-hydrate

The asymmetric unit of the title compound, C₇H₆O₅·0.25H₂O, contains two mol­ecules of 2,3,4-trihy­droxy­benzoic acid, with similar conformations, and one water mol­ecule which lies on a twofold rotation axis. Both acid mol­ecules are essentially planar [maximum r.m.s deviations = 0.0324 (2) and 0.0542 (3) Å for the two acid molecules]. The mol­ecular conformations are stabilized by intra­molecular O(phenol)—H...O(carbox­yl/phenol) inter­actions. A cyclic inter­molecular association is formed between the two acid and one water mol­ecule [graph set R₃³(12)] involving O—H...O hydrogen bonds. The two acid mol­ecules are further linked through a cyclic R₂²(8) carb­oxy­lic acid hydrogen-bonding association, which together with inter­molecular O—H...O hydrogen-bonding inter­actions involving the phenol groups and the water mol­ecule, and weak π–π inter­actions [minimum ring centroid separation = 3.731 (3) Å], give a three-dimensional network.

1,4-Bis(4H-1,2,4-triazol-4-yl)benzene dihydrate

The asymmetric unit of the title compound, C₁₀H₈N₆·2H₂O, comprises half the organic species, the mol­ecule being completed by inversion symmetry, and one water mol­ecule. The dihedral angle between the 1,2,4-triazole ring and the central benzene ring is 32.2 (2)°. The water mol­ecules form O—H...N hydrogen bonds with N-atom acceptors of the triazole rings. C—H...N hydrogen bonds are also observed, giving a three-dimensional framework.