The mol-ecule of the title compound, C(13)H(21)NO(8), consists of two methyl-enedi-oxy rings and one tetra-hydro-furan ring. In the crystal, inter-molecular O-H⋯O hydrogen bonds link the mol-ecules into helical chains running along the 6(1) screw axis. Weak inter-molecular C-H⋯O hydrogen bonds help to stabilize the crystal packing. Voids of 245 Å(3) per unit cell occur.