(4S,5S)-2,2-Dimethyl-1,3-dioxolane-4,5-dicarbo­nitrile

The title compound, C₇H₈N₂O₂, formed by dehydration of the corresponding dicarboxamide, crystallizes as rectangular prisms. The mol­ecules have a C₂ axis of symmetry through the C atom bearing the methyl groups and the mid-point of the ring C—C bond, and the 1,3-dioxolane ring adopts the extreme twist conformation of the two possible with this symmetry. This brings the two nitrile groups nearest to a linear arrangement when the mol­ecule is viewed along the ring C—C bond. The correct absolute configuration of the mol­ecule was defined by that of the original starting material, (2R,3R)-tartaric acid. The packing is largely controlled by a number of C—H...N interactions.