1,2:1',2'-Di-O-iso-propyl-idenedi-furan-ose-C12 higher carbon sugar

In the title compound, C18H28O8, the five-membered ring with one O atom attached to the ethyl substituent has a twisted conformation about the C-O bond. The adjacent cis-fused ring with two O atoms also has a twisted conformation about one of the C-O bonds. The dihedral angle between these rings (all atoms) is 59.05 (12)°. The five-membered ring linked to the ethynyl susbtituent is twisted about a C-C bond; the cis-fused adjacent ring is twisted about a C-O bond [dihedral angle between the rings (all atoms) = 71.78 (12)°]. Two intra-molecular O-H⋯O hydrogen bonds occur. In the crystal, mol-ecules are linked by O-H⋯O hydrogen bonds, generating [001] chains.