Three trans-2,6-Diaryl Derivatives of Oximes of N-Hydroxy-4-piperidone

In the solid state, trans-2,6-diphenyl-4-(hydroxyimino)piperidinol, C₁₇H₁₈N₂O₂, (1), trans-2,6-di(1-methylpyrrol-2-yl)-4-(hydroxyimino)piperidinol, C₁₅H₂₀N₄O₂, (2) and trans-2,6-di(thien-2-yl)-4-(hydroxyimino)piperidinol, C₁₃H₁₄N₂O₂S₂, (3) adopt conformations with an axial OH substituent on the ring N atom, in contrast to the preference for an equatorial conformation in solution. Molecules of all three structures are held together in chains by hydrogen bonding.

-1