Crystal structure of 2-amino-4-methyl­pyridin-1-ium (2R,3R)-3-carb­oxy-2,3-di­hydroxy­propano­ate monohydrate

The title mol­ecular salt, C₆H₉N₂⁺·C₄H₅O₆⁻·H₂O, crystallized with two 2-amino-4-methyl­pyridin-1-ium cations, two L-(+)-tartaric acid monoanions [systematic name: (2R,3R)-3-carb­oxy-2,3-di­hydroxy­propano­ate] and two water mol­ecules in the asymmetric unit. In the crystal, the cations, anions and water mol­ecules are linked via a number of O—H...O and N—H...O hydrogen bonds, and a C—H...O hydrogen bond, forming a three-dimensional structure

Crystal structure of 3-[4-(benz­yloxy)phen­yl]-2,3-di­hydro-1H-benzo[f]chromen-1-one

In the title compound, C₂₆H₂₀O₃, the pyran ring has a distorted half-chair conformation and its mean plane is inclined to the naphthalene ring system, to which it is fused, by 10.79 (9)°. The dihedral angles between the napthalene unit and the benzene and phenyl rings are 54.39 (9) and 52.65 (12)°, respectively, while the benzene and phenyl rings are inclined to one another by 74.80 (14)°. There is a short C—H...O contact in the chromen-1-one unit. In the crystal, mol­ecules are linked by two pairs of C—H...O hydrogen bonds, forming inversion dimers described by graph set motifs R₂²(8) and R₂²(10), giving rise to chains running parallel to (101). The chains are linked via C—H...π inter­actions, forming sheets lying parallel to (010).

Crystal structure of 4-methyl-N-{[1-(4-methyl­benzo­yl)piperidin-4-yl]meth­yl}benzamide

In the title compound, C₂₂H₂₇N₂O₂, the piperidine ring adopts a half-chair conformation with the benzene rings inclined in a trans orientation with respect to the piperidine ring [dihedral angle between the benzene rings = 89.1 (1)°]. In the crystal, a three-centre asymmetric N—H...O/C—H...O hydrogen-bonding inter­action leads to the formation of chains extending along the a-axis direction.

Crystal structure of (2E)-3-(3-eth­oxy-4-hy­droxy­phen­yl)-1-(4-hy­droxy­phen­yl)prop-2-en-1-one

In the title compound, C₁₇H₁₆O₄, the dihedral angle between the benzene rings is 21.22 (1)° and the mean plane of the prop-2-en-1-one group makes dihedral angles of 10.60 (1) and 11.28 (1)°, respectively, with those of the hy­droxy­phenyl and eth­oxy­phenyl rings. The eth­oxy substituent forms a dihedral angle of 88.79 (2)° with the the prop-2-en-1-one group, which is found to be slightly twisted. In the crystal, phenolic O—H...O hydrogen bonds to the carbonyl O atom form a two-dimensional supra­molecular network structure lying parallel to (010).