Dimethyl 2,2′-[(4-oxo-2-phenyl-4H-chromene-5,7-diyl)dioxy]diacetate: a more densely packed polymorph

The title mol­ecule, C(21)H(18)O(8), crystallizes in two crystal polymorphs, see also Nallasivam, Nethaji, Vembu & Jaswant [Acta Cryst. (2009), E65, o314–o315]. The mol­ecules of both polymorphs differ by the conformation of the oxomethyl­acetate groups. The title mol­ecules are rather planar compared to the mol­ecules of the other polymorph. In the title mol­ecule, one of the oxomethyl­acetate groups is disordered (occupancies of 0.6058/0.3942). The structures of both polymorphs are stabilized by C—H⋯O and C—H⋯π inter­actions. Due to the planarity of the title mol­ecules and similar inter­molecular inter­actions, the title mol­ecules are more densely packed than those of the other polymorph.