Crystal structure of 20ζ-hydroxy-3β-pyrrolidino-5-pregnene-16α-carbonitrile (HS1175): A novel design for neuromuscular blocking drugs

The structure of the title compound C26H38N2OH has been determined by direct methods from diffractometer data and refined by full-matrix least-squares. Crystals are monoclinicP21,a=6.237(1),b=10.295(2),c=18.485(2) Å, β=98.76(1)o,Z=2,Dc=1.12 g cm−3,R=0.055 for 1059 observed reflections. The structure has two N-containing functional groups, one each in the pyrrolidine ring and carbonitrile groups, with interatomic separation of 11.527 Å. The 16-carbonitrile group is α-oriented. All steroid rings are trans-connected, A and C being in chair conformations and B and D half-charis. N(23) in the carbonitrile side-chair forms a weak tail-tail hydrogen-bond network by linking with the neighboring OH(20) hydroxy group at 1−x, 1/2+y, 1−z.