rac-Ethyl 2-hy­droxy-2,7,7-trimethyl-4-(4-nitro­phen­yl)-5-oxo-3,4,5,6,7,8-hexa­hydro-2H-chromene-3-carboxyl­ate

The title mol­ecule, C₂₁H₂₅NO₇, has four stereogenic centres and crystallized as a racemate. It consists of enanti­omeric pairs with the relative configuration rac-(1R*,2S*,3R*). The cyclo­hexenone ring adopts an envelope conformation; the dimethyl-substituted C atom lies 0.640 (1) Å out of the mean plane formed by the rest of the ring atoms (r.m.s. deviation = 0.016 Å). The oxacyclo­hexene ring adopts a half-chair conformation, the hy­droxy- 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 mol­ecules into a chain along the c-axis direction.

rac-1-[6-Hy­droxy-4-(4-meth­oxy­phen­yl)-3,6-dimethyl-4,5,6,7-tetra­hydro-2H-indazol-5-yl]ethanone

The title compound, C₁₈H₂₂N₂O₃, represents a (4S,5R,6S)-stereoisomer, crystallizing as a racemate in a centrosymmetric space group. The six-membered aliphatic ring adopts a half-chair conformation, with the hy­droxy- and acetyl-substituted C atoms deviating by 0.458 (2) and −0.366 (2) Å, respectively, from the plane defined by other four ring atoms. The pyrazole ring is essentially planar [r.m.s deviation = 0.004 (2) Å]. In the crystal, the mol­ecules are linked into chains along the b axis by N—H...N hydrogen bonds. The chains are linked by O—H...N hydrogen bonds into layers parallel to the bc plane.

(1R*,2R*,3S*,4R*)-Diethyl 4-hy­droxy-4-methyl-2-(4-methyl­phen­yl)-6-oxo­cyclo­hexane-1,3-di­carboxyl­ate

The title compound, C₂₀H₂₆O₆, is chiral and crystallizes as a racemate: the relative configuration of the stereogenic centres is 1R*,2R*,3S*,4R*. The cyclo­hexane ring has a chair conformation. The ethyl fragment of the eth­oxy­carbonyl group in the 3-position is disordered over two sets of sites in a 0.650 (6):0.350 (6) ratio. The hy­droxy group acts as a bifurcated hydrogen-bond donor, forming both intra- and inter­molecular hydrogen bonds with ester carbonyl O atoms. The inter­molecular hydrogen bonds form inversion dimers in the crystal.