2,3-C-Dimethyl-3,4-O-isopropylidene-D-allono-1,5-lactone

The relative configuration of the title compound, C11H18O6, was firmly established by X-ray crystallographic analysis. The absolute configuration was determined by the use of 2-C-methyl-d-ribono-1,4-lactone as the starting material. The structure exists as a hydrogen-bonded network, with each mol­ecule acting as a donor and acceptor for two hydrogen bonds.