11-(3-Chloro-2-hydroxy­prop­oxy)-2,3,9-trimethoxy­chromeno[3,4-b]chromen-12(6H)-one

In the title compound, C22H21ClO8, the rotenoid core is nearly planar (r.m.s. deviation 0.114 Å), with the largest deviations from the least-squares plane being 0.286 (3) and 0.274 (2) Å. An inter­molecular O—H⋯O hydrogen bond links two mol­ecules into a centrosymmetric dimer having an R 2 2(18) ring motif