In the title compound, C(15)H(20)O(4)S, a dioxolane ring is fused to the pyran ring of the sugar which carries a thio-phenyl substituent on the anomeric C atom. The dioxolane ring adopts an envelope conformation and the pyran ring system a distorted (4)C(1) chair. The structure is stabilized by O-H⋯O hydrogen bonds, forming centrosymmetric dimers that generate an R(2) (2)(10) ring motif. Additional C-H⋯O inter-actions form an extended network. Two C atoms of the phenyl ring are disordered over two positions; the site occupancy factors are ca. 0.7 and 0.3.