The relative configuration and ring size of the title compound, C 7H12O6, were established by X-ray crystallographic analysis. The absolute configuration was determined by the use of 2-C-methyl-D-ribonolactone as a starting material. Almost all unprotected carbohydrate lactones are five-membered ring 1,4-lactones; the title compound provides a very rare example of a stable six-membered ring lactone. © 2007 International Union of Crystallography All rights reserved.
