title: 3,3'-Dihy-droxy-6,6'-bis-(hy-droxy-meth-yl)-2,2'-(pentane-1,1-di-yl)di-4H-pyran-4-one.
abstract: In the title mol-ecule, C(17)H(20)O(8), the two pyran rings form a dihedral angle of 61.2 (2)°. The two hy-droxy-methyl groups are each disordered over two sets of sites in a 0.764 (3):0.236 (3) ratio. In the crystal, O-H⋯O hydrogen bonds link the mol-ecules into layers parallel to the ac plane.
authors.forename: Mu-Song
authors.initials: MS
authors.lastname: Liu
authors.forename: Pan-Pan
authors.initials: PP
authors.lastname: Hu
authors.forename: Tao
authors.initials: T
authors.lastname: Zhou