6-[(4'-Ethoxycarbonyl-[1,1'-biphenyl]-4-yl)oxy]hexanoic acid.

In the title compound, C21H24O5, the dihedral angle between the benzene rings is 19.57 (15)°. In the crystal, the mol-ecular arrangement makes up head-to-head centrosymmetric dimers assembled by pairs of O-H⋯O bonds; this arrangement builds a graph-set ring motif of R (2) 2(8). The dimers are linked into a tape running along the b-axis direction through C-H⋯O inter-actions. The packing is further consolidated by C-H⋯π inter-actions, forming layers parallel to (10-2).