Telaprevir: helical chains based on three‐point hydrogen‐bond connections

The crystal structure of the title compound systematic name: (1S,3aR,6aS)‐2‐((2S)‐2‐{(2S)‐2‐cyclohexyl‐2‐(pyrazine‐2‐carbonylamino)acetyl]amino}‐3,3‐dimethylbutanoyl)‐N‐(3S)‐1‐(cyclopropylamino)‐1,2‐dioxohexan‐3‐yl]‐3,3a,4,5,6,6a‐hexahydro‐1H‐cyclopentac]pyrrole‐1‐carboxamide], C₃₆H₅₃N₇O₆, contains two independent molecules, which possess distinct conformations and a disordered cyclopentac]pyrrolidine unit. In the crystal, molecules are linked into helical chains via three‐point N—H...O hydrogen‐bond connections in which three NH and three carbonyl groups per molecule are utilized. The chiralities of the six stereocentres per molecule inferred from this study are in agreement with the synthetic procedure.