(4S)-4-Benzyl-N-{[(4S)-4-benzyl-2-oxo-1,3-oxazolidin-3-yl]sulfon-yl}-2-oxo-1,3-oxazolidine-3-carboxamide.

The title compound, C(21)H(21)N(3)O(7)S, contains an oxazolidinone ring and a sulfonamide group, both characteristic for biologically and pharrmaceutically active compounds. Both stereogenic centres reveal an S absolute configuration. The two oxazolidinone rings are in an envelope conformation with the methyl-ene carbon flap atoms deviating by 0.428 (1) and 0.364 (2) Å from the best least-square planes formed by the four other ring atoms. An intra-molecular N-H⋯O hydrogen bond contributes to the folded conformation of the mol-ecule. In the crystal, weak inter-molecular C-H⋯O inter-actions connect the mol-ecules into helices along the the twofold screw axes.