3,3′-Dihy­droxy-6,6′-bis­(hy­droxy­meth­yl)-2,2′-(pentane-1,1-di­yl)di-4H-pyran-4-one

In the title mol­ecule, C₁₇H₂₀O₈, the two pyran rings form a dihedral angle of 61.2 (2)°. The two hy­droxy­methyl 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 mol­ecules into layers parallel to the ac plane.