Synthesis and X-ray crystallography of cholest-3,5-diene-7-one-oxime

Abstract

Cholest-3,5-diene-7-one-oxime (C₂₇H₄₃NO) was prepared using a usual synthetic route and its three-dimensional structure was determined by X-ray diffraction methods. The transparent platelike crystals of this compound crystallized in the monoclinic space group P2₁, with unit cell parameters a = 14.302(2) Å, b = 11.475(2) Å, c = 15.919(4) Å, β = 106.04(1)°, λ (Cu Kα) = 1.5418 Å, Z = 4. The structure was solved by direct methods and refined to an R-value of 0.075 for 4640 observed reflections. Two crystallographically independent molecules were observed in the asymmetric unit cell. The ring A in both the molecules was found to exist in 1α,10β half-chair conformation while ring C in chair conformation. The rings B and D in both the molecules adopted different conformations. Three intermolecular interactions of the type C–H ⋅ ⋅ ⋅ O and C–H ⋅ ⋅ ⋅ N were also observed.