X-ray structure analysis of 3β-hydroxy-4-(1,4-oxazin-4-yl)-androstane (C31H54NO2)

The crystal structure of 3β-hydroxy-4-(1,4-oxazin-4-yl)-androstane (C₃₁H₅₄NO₂) has been determined by X-ray crystallographic techniques. The compound crystallizes in the orthorhombic space group P2₁2₁2 with the following unit-cell parameters: a = 7.124(1) Å, b = 10.127(1) Å, c = 40.660(1) Å, V = 2933.4(1) ų, and Z = 4. The structure has been solved by direct methods and refined to an R factor of 0.067. Three six-membered rings, A, C, and E, exist in the chair conformation, while the ring B adopts a distorted half-chair conformation. The five-membered ring, D, has a distorted envelope conformation. The crystal structure is stabilized by strong intermolecular O-H...O hydrogen bonds.     

Synthesis and structure determination of 3β-hydroxyandrost-5-en-17-one (C19H28O2·CH3OH)

3-Hydroxyandrost-5-en-17-one (C₁₉H₂₈O₂.CH₃OH) has been prepared for undertaking its crystallographic analysis and to investigate the role of intra- and intermolecular interactions in steroids. The title compound crystallizes in the orthorhombic space group C222₁ with unit cell parameters a = 6.7892(17), b = 12.624(2), and c = 41.136(5) Å; V = 3525.7(12) ų and Z = 8. The three-dimensional structure has been solved by direct methods. The final reliability index for the computed structure is 0.050 for 1088 observed reflections. Ring A exist in chair conformation, Ring B in half-chair conformation, and the Ring C assumes a distorted chair conformation. The five-membered Ring D adopts half-chair conformation. The A/B ring junction is quasi-trans while as B/C and C/D are trans-fused. The oxygen atom of the solvent molecule (CH₃OH) is involved in O–H···O intermolecular interaction.     

Synthesis and X-ray crystallographic analysis of 17α-hydroxy-17-methylandrost-4-ene-17-one

17α-Hydroxy-17-methylandrost-4-ene-17-one is a complex of two steroid molecules with water and its crystal structure has been determined by X-ray crystallographic techniques. The transparent plate-like crystals of this compound crystallized in the orthorhombic space group P2₁2₁2₁, with unit cell parameters: a = 6.382(2), b = 12.841(5), c = 43.350(2) ?, λ(Mo Kα) = 0.71073 ?, Z = 8. The structure has been solved by direct methods and refined to R = 0.047, wR = 0.086. There are two crystallographically independent molecules, I and II, in the asymmetric unit. In both the molecules, rings A and D adopt a distorted half-chair conformation while rings B and C exist in chair conformation. The crystal structure is stabilized by intermolecular O−H⋯O and C−H⋯O hydrogen bonds.     

Synthesis and structure analysis of 2-(2′-propanonylthio)-3-(o-methyl phenyl) quinazol-4(3H)-one

The three-dimensional molecular and crystal structure of 2-(2'-propanonylthio)3-(o-methyl phenyl)quinazol-4(3H)-one has been determined by X-ray crystallographic methods. This compound crystallizes in the orthorhombic space group P_bca with unit cell parameters: a=9.649(5), b=30.102(10), c=11.403(9)Å. It has been solved by direct methods and refined to a residual index of 0.054. The magnitude of torsion along C16— C11— N3— C4 bond is 93.5(4)°. The dihedral angle between the plane comprising all the ring atoms of quinazoline moiety and the atoms of the methyl substituted phenyl ring is 94.12(1)°. The crystal structure is stabilized by one intramolecular C— HsO interaction and three intermolecular C— HsN contacts.     

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

The molecular structure of cholest-3,5-diene-7-one (C₂₇H₄₂O) is determined by X-ray diffraction. The compound crystallizes in the orthorhombic crystal system (space group P2₁2₁2₁) with unit cell parameters a = 11.281(5) Å, b = 11.350(5) Å, c= 18.518(5) Å, and Z = 4. The structure is solved by direct methods and refined to an R-value of 0.054 for 1070 observed reflections [F_o > 4σ(F_o)]. Ring A adopts a distorted half-chair conformation, ring B exists in sofa conformation, ring C acquires a chair conformation, and the five-membered ring D occurs in distorted half-chair conformation. The crystal structure is stabilized by van der Waals forces.     

Crystal structure of 17α‐acetoxyprogesterone,C23H32O4

The crystal structure of the title compound (C₂₃H₃₂O₄) has been determined by X‐ray diffraction methods. It crystallizes in the orthorhombic space group P2₁2₁2₁ with cell parameters: a = 10.86(1), b = 11.95(2), c = 15.65(5) Å and Z = 4. The structure has been refined to an R‐value of 0.045 for 1610 observed reflections. Ring A exists in sofa conformation, Ring B adopts a distorted chair conformation while as Ring C assumes a chair conformation. The five membered ring D adopts a half‐chair conformation. The crystal structure is stabilized by intra‐ and intermolecular C‐H…O interactions. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)