An ortho­rhom­bic polymorph of 3-oxapentane-1,5-diyl bis­( p-toluene­sulfonate).

An ortho­rhom­bic (space group Pbcn) polymorph of the title compound, C18H22O7S2, was obtained from a methanol solution to complement the known monoclinic (space group C2/ c) phase. No phase transition has been found between the two systems in the temperature range 120–296 K. The central O atom of the mol­ecule has site symmetry 2. [ABSTRACT FROM AUTHOR]