(S)-2,2′-Dihy­droxy-N,N′-(6-hy­droxy­hexane-1,5-di­yl)dibenzamide

In the title compound, C(20)H(24)N(2)O(5), the dihedral angle between the two roughly planar salicyl­amide fragments [r.m.s. deviations = 0.043 (2) and 0.149 (2) Å] is 25.50 (5)°. The mol­ecular conformation is stabilized by intra­molecular O—H⋯O hydrogen bonds involving phenol –OH groups and amide O atoms. Inter­molecular hy­droxy­meth­yl–amide O—H⋯O and amine–hy­droxy­methyl N—H⋯O hydrogen bonds form infinite chains along the b axis. These chains are further inter­linked by amine–amide N—H⋯O and phenol–phenol O—H⋯O inter­actions, thus giving layers parallel to (001).