Crystal structure of potassium (1R)-d-ribit-1-yl­sulfonate

The title compound, K(+)·C(5)H(11)O(8)S(−) [systematic name: potassium (1R,2R,3R,4R)-1,2,3,4,5-penta­hydroxy­pentane-1-sulfonate], formed by reaction of d-ribose with potassium hydrogen sulfite in water, crystallizes as colourless plates. The anion has an open-chain structure in which the S atom and the C atoms of the sugar chain, excepting that of the hy­droxy­methyl group, form an essentially all-trans chain; the C atom of the hy­droxy­methyl group lies in a gauche relationship with the three contiguous C atoms. Through complex cation coordination (through seven oxygen atoms of six different anions) and inter­molecular O—H⋯O hydrogen bonding, a three-dimensional bonding network exists in the crystal structure.