Synthesis and crystal structures of a bis-(3-hy-droxy-cyclo-hex-2-en-1-one) and two hexa-hydro-quinoline derivatives.

The title compound I, 2,2'-[(2-nitro-phen-yl)methyl-ene]bis-(3-hy-droxy-5,5-di-methyl-cyclo-hex-2-enone), C(23)H(27)NO(6), features a 1,3-ketone-enol conformation which is stabilized by two intra-molecular hydrogen bonds. The most prominent inter-molecular inter-actions in compound I are C-H⋯O hydrogen bonds, which link mol-ecules into a two-dimensional network parallel to the (001) plane and a chain perpendicular to (11). Both title compounds II, ethyl 4-(4-hy-droxy-3,5-di-meth-oxy-phen-yl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexa-hydro-quinoline-3-carb-oxyl-ate, C(23)H(29)NO(6), and III, ethyl 4-(anthracen-9-yl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexa-hydro-quinoline-3-carboxyl-ate, C(29)H(29)NO(3), share the same structural features, such as a shallow boat conformation of the di-hydro-pyridine group and an orthogonal aryl group attached to the di-hydro-pyridine. Inter-molecular N-H⋯O bonding is present in the crystal packing of both compound II and III.