title: 7,7'-Dihy-droxy-4,4'-dimethyl-3,4-dihydro-2H,2'H-4,6'-bichromene-2,2'-dione.
abstract: The title compound, C(20)H(16)O(6), which contains one chiral centre, crystallizes as a racemate. The mean planes of the two coumarin units make a dihedral angle of 88.07 (2)°. The pyrone ring containing the chiral centre adopts a sofa conformation. In the crystal, four mol-ecules are linked by O-H⋯O hydrogen bonds, forming a tetrameric ring with graph-set motif R(4) (4)(32). These tetramers are further linked by O-H⋯O hydrogen bonds into a three-dimensional network.
authors.forename: P S
authors.initials: PS
authors.lastname: Pereira Silva
authors.forename: Mehtab
authors.initials: M
authors.lastname: Parveen
authors.forename: Akhtar
authors.initials: A
authors.lastname: Ali
authors.forename: Ali Mohammed
authors.initials: AM
authors.lastname: Malla
authors.forename: M
authors.initials: M
authors.lastname: Ramos Silva