organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoSTRUCTURAL
CHEMISTRY
ISSN: 2053-2296

21-De­oxycortisone (17α-hy­droxy-4-pregnene-3,11,20-trione)

aCentre for Structural Biology, Department of Chemistry and Bioscience, Chalmers University of Technology, Box 462, Gothenburg 40530, Sweden, bSubdivision of Inorganic Environmental Chemistry, Division of Materials and Surface Chemistry, Department of Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden, cDepartment of Physics, University of Calcutta, 92 A.P.C. Road, Calcutta 700 009, India, dX-ray Laboratory, Department of Physics, Presidency College, Calcutta 700 073, India, and eDepartment of Chemistry, The University of Reading, PO Box 224, Whiteknights, Reading RG6 6AD, England
*Correspondence e-mail: raja.dey@molbiotech.chalmers.se

(Received 20 December 2004; accepted 2 February 2005; online 11 March 2005)

The title compound, C21H28O4, a synthetic glucocorticoid, crystallizes with a single mol­ecule in the asymmetric unit. Ring A is almost in a half-chair conformation, rings B and C are almost in chair conformations, and ring D is between a twist and a 13β-envelope conformation. The A/B ring junction is quasi-trans, whereas the B/C and C/D ring junctions both approach trans characteristics. The mol­ecule as a whole is slightly convex towards the β side, with an angle of 9.60 (2)° between the C10—C19 and C13—C18 vectors. Mol­ecular-packing and hydrogen-bonding (both intra- and inter­molecular) inter­actions play a major role in the structural association of the compound.

Comment

The hormones of the adrenal cortex, particularly the glucocorticoids, are an essential component of adaptation to severe stress. Synthetic analogues of this class of steroid are used therapeutically (Murray et al., 1990[Murray, R. K., Granner, D. K., Mayes, P. A. & Rodwell, V. W. (1990). Harper's Biochemistry, 22nd ed., pp. 499-508. London: Prentice Hall International Inc.]). The title compound, (I)[link], belongs to the class of hormones which affect specific cellular processes by influencing the number of enzymes within the cell through regulation of the rate of transcription of specific genes in the target cell. The glucocorticoid complexed with its receptor plays a major role in this regulation of transcription (Murray et al., 1990[Murray, R. K., Granner, D. K., Mayes, P. A. & Rodwell, V. W. (1990). Harper's Biochemistry, 22nd ed., pp. 499-508. London: Prentice Hall International Inc.]). Introduction of an 11-oxo group to cortisone decreases its binding affinity with human cortico­steroid binding globulin (Mickelson et al., 1981[Mickelson, K. E., Forsthoefel, J. & Westphal, U. (1981). Biochemistry, 20, 6211-6218.]). Glucocorticoid receptors show high binding affinity to glucocorticoids (Westphal, 1983[Westphal, U. (1983). J. Steroid Biochem. 19, 1-15.]). The structural analysis of (I)[link] may eventually lead to a better understanding of its mode of binding with its receptor. We have therefore elucidated the three-dimensional structure of (I)[link]. In the scheme, the asymmetric C atoms are indicated by asterisks.

In the mol­ecule of (I)[link], ring A has a nearly half-chair conformation, with an α-H atom at C4. Rings B and C are almost in chair conformations, with an α-H atom at C9 and a β-H atom at C8. Ring D is between a twist and a 13β-envelope conformation, with an α-H atom at C14. The conformations of the rings were calculated using PLATON (Spek, 2003[Spek, A. L. (2003). J. Appl. Cryst. 36, 7-13.]). The BC and C/D ring junctions approach trans characteristics, whereas the A/B ring junction is quasi-trans (Bucourt, 1974[Bucourt, R. (1974). The Torsion Angle Concept in Conformational Analysis, in Topics in Stereochemistry, edited by E. L. Eliel & N. L. Allinger, Vol. 8, p. 159. New York: Interscience.]). This quasi characteristic of the A/B trans ring junction is due to the existence of the trigonal atom C5. A list of the endocyclic torsion angles about the three ring junctions, which support the above-mentioned ring-junction characteristics, is given in Table 2[link].

[Scheme 1]

The twist of the mol­ecule of (I)[link] about its length when viewed from head to tail is determined by the C19—C10⋯C13—C18 pseudo-torsion angle. This has a value of −3.3 (3)°, which implies that the tail of the mol­ecule is twisted slightly anticlockwise by that angle. Moreover, the mol­ecule is slightly convex towards the β side, with an angle of 9.60 (2)° between the C10—C19 and C13—C18 vectors. Final bond lengths and bond angles agree well with the published values (Duax & Norton, 1975[Duax, W. L. & Norton, D. A. (1975). Atlas of Steroid Structures, Vol. 1, pp. 462-473. New York: Plenum.]). The s.u. values for the bond lengths lie within the range 0.005–0.008 Å and those for the bond angles lie within the range 0.3–0.5°. A list of the functional groups, with their orientations and deviations from the C5–C17 mean plane (determined by all the atoms of the B, C and D rings) and the angles subtended at the C5–C17 mean plane, is given in Table 3[link]. Here, the angle subtended by a functional group at the C5–C17 mean plane is obtained by calculating the angle between the normal to this mean plane towards the β side and the line joining the functional group to the bonded C atom.

It is well known that the conformation of ring A is considered to be a key factor in binding steroids to their receptors (Duax et al., 1984[Duax, W. L., Griffin, J. F., Rohrer, D. C., Weeks, C. M. & Ebright, R. H. (1984). Biochemical Actions of Hormones, Vol. XI, pp. 187-205. New York: Academic Press.]). Since the pregnene mol­ecule exhibits a certain degree of flexibility in the region of ring A, it can be accommodated in the ligand-binding domain of its receptor by changing the orientation of ring A relative to the mean plane passing through all the atoms of rings B, C and D. A major conformational difference between the four cortisone structures, viz. 17α,21-dihydr­oxy-4-pregnene-3,11,20-trione (PR20), 21-acet­oxy-17α-hydr­oxy-4-pregnene-3,11,20-trione (PR21) and 4-chloro-17α,21-dihydr­oxy-4-pregnene-3,11,20-trione (PR22) (Duax & Norton, 1975[Duax, W. L. & Norton, D. A. (1975). Atlas of Steroid Structures, Vol. 1, pp. 462-473. New York: Plenum.]), and 17α-hydroxy-4-pregnene-3,11,20-trione, (I)[link], are in the conformation of ring A. Ring A has a symmetric half-chair conformation in PR20, a distorted sofa conformation in PR21, a sofa conformation in PR22 (Duax & Norton, 1975[Duax, W. L. & Norton, D. A. (1975). Atlas of Steroid Structures, Vol. 1, pp. 462-473. New York: Plenum.]) and a nearly half-chair conformation in (I)[link]. The distance between atom O3 and the plane is usually used as a measure of the bow of a 4-en-3-one steroid mol­ecule (Galdecki et al., 1989[Galdecki, Z., Grochulski, P., Wawrzak, Z. & Duax, W. L. (1989). J. Crystallogr. Spectrosc. Res. 19, 949-955.]). The bowing of ring A relative to the remainder of the steroid (A/BCD) is −32.3° for PR20, −21.5° for PR21, −15° for PR22 (Duax & Norton, 1975[Duax, W. L. & Norton, D. A. (1975). Atlas of Steroid Structures, Vol. 1, pp. 462-473. New York: Plenum.]) and 24.8 (2)° for (I)[link]. The projection of the steroid mol­ecule viewed parallel to the least-squares plane through atoms C5–C17 is shown in Fig. 2[link]. The C13—C17—C20—O20 and C16—C17—C20—O20 torsion angles are 85.1 (5) and −31.7 (6)°, respectively, which suggests that atom O20 is in a synclinal position with respect to both C13 and C16 (Klyne & Prelog, 1960[Klyne, W. & Prelog, V. (1960). Experientia, 16, 521-523.]). Atoms C17, C20, O20 and C21 of the 17β side chain are coplanar (to within ±0.004 Å). The 17α substituent is 0.578 (5) Å from this plane. The dihedral angle between this plane and the C5–C17 reference plane is 122.0 (3)°.

The unit-cell packing of (I)[link], including the hydrogen-bonding network, is shown in Fig. 3[link]. In the crystal packing of (I)[link], an infinite chain of steroid mol­ecules is formed by hydrogen bonding in a head-to-tail fashion. Mol­ecules are connected by means of inter­molecular hydrogen bonds formed by the donor, the hydrox­yl group at C17, with the common keto O-­atom acceptor at C3 (Table 1[link]). A short inter­molecular contact of less than 3.5 Å playing an important role in the crystal packing is O11⋯O17ii = 3.466 (6) Å [symmetry code: (ii) x + 1, y, z].

[Figure 1]
Figure 1
A three-dimensional view of (I)[link], with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii.
[Figure 2]
Figure 2
A projection of the structure of (I)[link] parallel to the C5–C17 mean plane.
[Figure 3]
Figure 3
The mol­ecular packing of (I)[link], showing the hydrogen bonding joining the mol­ecules in a helical fashion with a threefold screw axis.

Experimental

The stereospecific synthetic compound 21-de­oxycortisone (17α-hy­droxy-4-pregnene-3,11,20-trione), (I)[link], was purchased from Sigma and crystallized from a solution in ethanol. The crystals are dark brown in colour and transparent, and are quite stable at room temperature.

Crystal data
  • C21H28O4

  • Mr = 344.43

  • Trigonal, P 31

  • a = 7.297 (2) Å

  • c = 30.304 (3) Å

  • V = 1397.4 (6) Å3

  • Z = 3

  • Dx = 1.228 Mg m−3

  • Dm = 1.25 Mg m−3

  • Dm measured by flotation in benzene–bromoform

  • Mo Kα radiation

  • Cell parameters from 50 reflections

  • θ = 3.2–25.7°

  • μ = 0.08 mm−1

  • T = 153.7 (1) K

  • Pyramidal, brown

  • 0.45 × 0.34 × 0.28 mm

Data collection
  • Marresearch image-plate diffractometer

  • φ scans

  • 6746 measured reflections

  • 1755 independent reflections

  • 1531 reflections with I > 2σ(I)

  • Rint = 0.059

  • θmax = 25.7°

  • h = −7 → 8

  • k = −8 → 8

  • l = −36 → 36

Refinement
  • Refinement on F2

  • R[F2 > 2σ(F2)] = 0.065

  • wR(F2) = 0.132

  • S = 1.19

  • 1755 reflections

  • 230 parameters

  • H-atom parameters constrained

  • w = 1/[σ2(Fo2) + (0.0494P)2 + 0.6658P] where P = (Fo2 + 2Fc2)/3

  • (Δ/σ)max = 0.001

  • Δρmax = 0.19 e Å−3

  • Δρmin = −0.21 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
O17—H17⋯O3i 0.82 2.34 3.094 (5) 154
Symmetry code: (i) [-x+y+1, -x+2, z-{\script{1\over 3}}].

Table 2
Endocyclic torsion angles (°) about the ring junctions in (I[link])

Junction Atoms Angle Characteristics
A/B C4—C5—C10—C1 −12.6 (7) Quasi-trans
  C6—C5—C10—C9 49.1 (6)  
B/C C7—C8—C9—C10 55.3 (5) trans
  C14—C8—C9—C11 −49.6 (5)  
C/D C12—C13—C14—C8 −61.1 (5) trans
  C17—C13—C14—C15 47.6 (4)  

Table 3
Functional groups of (I[link]), with their orientations, distances (Å) from the C5–C17 mean plane and angles (°) subtended at the C5–C17 mean plane

Functional group Orientation Distance Angle
C18 β axial 1.834 (5) 4.6 (3)
C19 β axial 1.779 (6) 7.0 (3)
O3 α axial −1.854 (5) 123.0 (4)
O11 β equatorial 0.804 (4) 60.4 (3)
O17 α axial −1.702 (4) 170.4 (3)
O20 β axial 1.325 (5) 31.6 (3)
C21 α equatorial −0.436 (7) 119.1 (3)

Preliminary cell parameters and symmetry information were obtained from oscillation and Weissenberg photographs. All H atoms were included in the riding-model approximation, with C—H distances in the range 0.93–0.98 Å and an O—H distance of 0.82 Å, and with Uiso(H) = 1.2Ueq(C,O).

Data collection, cell refinement and data reduction: XDS (Kabsch, 1988[Kabsch, W. (1988). J. Appl. Cryst. 21, 916-932.]); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997[Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997[Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany.]); molecular graphics: DIAMOND (Brandenburg, 2004[Brandenburg, K. (2004). DIAMOND. Version 3. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: PLATON (Spek, 2003[Spek, A. L. (2003). J. Appl. Cryst. 36, 7-13.]).

Supporting information


Comment top

The hormones of the adrenal cortex, particularly the glucocorticoids, are an essential component of adaptation to severe stress. Synthetic analogues of this class of steroid are used therapeutically (Murray et al., 1990). The title compound, (I), belongs to the class of hormones which affect specific cellular processes by influencing the number of enzymes within the cell, by regulating the rate of transcription of specific genes in the target cell. The glucocorticoid complexed with its receptor plays a major role in this regulation of transcription (Murray et al., 1990). Introduction of an 11-oxo group to cortisone decreases its binding affinity with human corticosteroid binding globulin (Mickelson et al., 1981). Glucocorticoid receptors show high binding affinity to glucocorticoids (Westphal, 1983). The structural analysis of the title compound, (I), may eventually lead to a better understanding of its mode of binding with its receptor. We have therefore elucidated the three-dimensional structure of (I). In the scheme, the asymmetric C atoms are indicated by asterisks.

In the molecule of (I), ring A has a nearly half-chair conformation, with an α-H atom at C4. Rings B and C are almost in chair conformations, with an α-H atom at C9 and a β-H atom at C8. Ring D is in between a twist and a 13β-envelope conformation, with an α-H atom at C14. The conformations of the rings were calculated using PLATON (Spek, 2003). The B/C and C/D ring junctions approach trans characteristics, whereas the A/B ring junction is quasi-trans (Bucourt, 1974). This quasi characteristic of the A/B trans ring junction is due to the existence of the trigonal atom C5. A list of the endocyclic torsion angles about the three ring junctions, which support the above-mentioned ring-junction characteristics, is given in Table 2.

The twist of the molecule of (I) about its length when viewed from head to tail is determined by the C19—C10···C13—C18 pseudo torsion angle. This has a value of −3.3 (3)°, which implies that the tail of the molecule is twisted slightly anticlockwise by that angle. Moreover, the molecule is slightly convex towards the β side, with an angle of 9.60 (2)° between the C10—C19 and C13—C18 vectors. Final bond lengths and bond angles agree well with the published values (Duax & Norton, 1975). The s.u.s for the bond lengths lie within the range 0.005–0.008 Å, and those for the bond angles lie within the range 0.3–0.5°. A list of the functional groups, with their orientations and deviations from the C5–C17 mean plane (determined by all the atoms of the B, C and D rings) and the angles subtended at the C5–C17 mean plane, is given in Table 3. Here, the angle subtended by a functional group at the C5–C17 mean plane is obtained by calculating the angle between the normal to this mean plane towards the β side and the line joining the functional group to the bonded C atom.

It is well known that the conformation of ring A is considered to be a key factor in binding steroids to their receptors (Duax et al., 1984). Since the pregnen molecule exhibits a certain degree of flexibility in the region of ring A, it can be accommodated in the ligand-binding domain of its receptor by changing the orientation of ring A relative to the mean plane passing through all the atoms of rings B, C and D. A major conformational difference between the four cortisone structures, viz, 17α,21-dihydroxy-4-pregnene-3,11,20-trione (PR20), 21-acetoxy-17α-hydroxy-4-pregnene-3,11,20-trione (PR21) and 4-chloro-17α,21-dihydroxy-4-pregnene-3,11,20-trione (PR22) (Duax & Norton, 1975), and 4-pregnene-17α-ol-3,11,20-trione, (I), are in the conformation of ring A. The A ring has a symmetric half-chair conformation in PR20, a distorted sofa conformation in PR21, a sofa conformation for PR22 (Duax & Norton, 1975) and a nearly half-chair conformation for (I). The distance between atom O3 and the plane is usually used as a measure of the bow of a 4-en-3-one steroid molecule (Galdecki et al., 1989). The bowing of ring A relative to the remainder of the steroid (A/BCD) is −32.3 for PR20, −21.5 for PR21, −15 for PR22 (Duax & Norton, 1975) and 24.8 (2)° for (I). The projection of the steroid molecule viewed parallel to the least-squares plane through atoms C5–C17 is shown in Fig. 2. The C13—C17—C20—O20 and C16—C17—C20—O20 torsion angles are 85.1 (5) and −31.7 (6)°, respectively, which suggests that atom O20 is in a synclinal position with respect to both C13 and C16 (Klyne & Prelog, 1960). Atoms C17, C20, O20 and C21 of the 17β side chain are coplanar (to within ±0.004 Å). The 17α substituent is 0.578 (5) Å from this plane. The dihedral angle between this plane and the C5–C17 reference plane is 122.0 (3)°.

The unit-cell packing of (I), viewed down the b axis and including the hydrogen-bonding network, is shown in Fig. 3. In the crystal packing of (I), an infinite chain of steroid molecules is formed by hydrogen bonding in a head-to-tail fashion. Molecules are connected by means of intermolecular hydrogen bonds formed by the donor, the hydroxyl group at C17, with the common keto O acceptor at C3 (Table 1). A short intermolecular contact of less than 3.5 Å playing an important role in the crystal packing is O11···O17ii = 3.466 (6) Å [symmetry code: (ii) x + 1, y, z].

Experimental top

The stereospecific synthetic compound 21-de-oxy cortisone (4-pregnen-17 A-ol-3,11,20-trione), (I), was purchased from SIGMA and crystallized from a solution in ethanol. The crystals are dark-brown in colour and transparent and are quite stable at room temperature.

Refinement top

Preliminary cell parameters and symmetry information were obtained from oscillation and Weissenberg photographs. All H atoms were included in the riding-model approximation, with C—H distances in the range 0.93–0.98 Å and an O—H distance of 0.82 Å, and with Uiso(H) = 1.2Ueq(C,O). Please check added text.

Computing details top

Data collection: Please provide missing details and reference; cell refinement: Please provide missing details and reference; data reduction: Please provide missing details and reference; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg, 2004); software used to prepare material for publication: PLATON (Spek, 2003).

Figures top
[Figure 1] Fig. 1. A three-dimensional view of (I), with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii.
[Figure 2] Fig. 2. A projection of the structure of (I) parallel to the C5–C17 mean plane.
[Figure 3] Fig. 3. The molecular packing of (I), showing the hydrogen bonding joining the molecules in a helical fashion with a threefold screw axis.
4-Pregnen-17 A-ol-3,11,20-trione top
Crystal data top
C21H28O4Dx = 1.228 Mg m3
Dm = 1.25 Mg m3
Dm measured by flotation in what
Mr = 344.43Mo Kα radiation, λ = 0.71073 Å
Trigonal, P31Cell parameters from 50 reflections
Hall symbol: P 31θ = 3.2–25.7°
a = 7.297 (2) ŵ = 0.08 mm1
c = 30.304 (3) ÅT = 154 K
V = 1397.4 (6) Å3Pyramid, brown
Z = 30.45 × 0.34 × 0.28 mm
F(000) = 558
Data collection top
MARResearch image plate
diffractometer
1531 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.059
Graphite monochromatorθmax = 25.7°, θmin = 3.2°
ϕ scansh = 78
6746 measured reflectionsk = 88
1755 independent reflectionsl = 3636
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.065Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.132H-atom parameters constrained
S = 1.19 w = 1/[σ2(Fo2) + (0.0494P)2 + 0.6658P]
where P = (Fo2 + 2Fc2)/3
1755 reflections(Δ/σ)max = 0.001
230 parametersΔρmax = 0.19 e Å3
1 restraintΔρmin = 0.21 e Å3
Crystal data top
C21H28O4Z = 3
Mr = 344.43Mo Kα radiation
Trigonal, P31µ = 0.08 mm1
a = 7.297 (2) ÅT = 154 K
c = 30.304 (3) Å0.45 × 0.34 × 0.28 mm
V = 1397.4 (6) Å3
Data collection top
MARResearch image plate
diffractometer
1531 reflections with I > 2σ(I)
6746 measured reflectionsRint = 0.059
1755 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0651 restraint
wR(F2) = 0.132H-atom parameters constrained
S = 1.19Δρmax = 0.19 e Å3
1755 reflectionsΔρmin = 0.21 e Å3
230 parameters
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
C11.1724 (7)0.6158 (8)0.24317 (15)0.0373 (12)
H1A1.30060.66590.22590.045*
H1B1.15380.73610.24910.045*
C21.2005 (9)0.5294 (9)0.28696 (17)0.0469 (14)
H2A1.23560.41970.28130.056*
H2B1.31670.64210.30320.056*
C31.0015 (9)0.4395 (8)0.31435 (16)0.0413 (13)
O31.0046 (7)0.4451 (7)0.35462 (12)0.0609 (12)
C40.8050 (9)0.3342 (9)0.28968 (16)0.0423 (13)
H40.67970.26590.30570.051*
C50.7902 (8)0.3278 (7)0.24532 (16)0.0344 (11)
C60.5831 (8)0.1922 (10)0.22254 (17)0.0512 (16)
H6A0.58390.07060.20980.061*
H6B0.47060.14010.24430.061*
C70.5358 (7)0.3032 (9)0.18727 (17)0.0408 (13)
H7A0.50270.40360.20080.049*
H7B0.41120.20050.17130.049*
C80.7159 (7)0.4209 (7)0.15446 (15)0.0289 (10)
H80.73630.31760.13770.035*
C90.9236 (7)0.5692 (7)0.18024 (14)0.0250 (9)
H90.89130.66420.19710.030*
C100.9833 (7)0.4530 (7)0.21558 (13)0.0271 (10)
C111.1005 (7)0.7146 (7)0.14810 (15)0.0289 (10)
O111.2756 (5)0.7335 (6)0.14817 (12)0.0444 (9)
C121.0453 (7)0.8397 (7)0.11543 (15)0.0320 (11)
H12A1.16240.91840.09530.038*
H12B1.01810.93940.13120.038*
C130.8466 (7)0.6822 (7)0.08943 (14)0.0258 (10)
C140.6663 (6)0.5514 (7)0.12243 (14)0.0263 (10)
H140.64550.65200.14010.032*
C150.4712 (7)0.4336 (8)0.09249 (16)0.0357 (11)
H15A0.34250.39820.10850.043*
H15B0.46070.30460.08100.043*
C160.5088 (7)0.5906 (8)0.05501 (16)0.0352 (11)
H16A0.40660.63850.05670.042*
H16B0.49420.52360.02660.042*
C170.7378 (7)0.7812 (7)0.06073 (15)0.0276 (10)
O170.7378 (6)0.9453 (6)0.08679 (11)0.0418 (9)
H170.64880.97220.07710.050*
C180.9021 (8)0.5425 (8)0.06081 (16)0.0352 (11)
H18A1.01310.62990.04060.053*
H18B0.77920.44330.04450.053*
H18C0.94840.46710.07940.053*
C191.0337 (9)0.2900 (9)0.19386 (18)0.0436 (13)
H19A1.06900.22030.21640.065*
H19B1.15100.36210.17400.065*
H19C0.91210.18710.17780.065*
C200.8483 (8)0.8761 (8)0.01662 (17)0.0358 (11)
O200.8095 (7)0.7654 (7)0.01577 (12)0.0586 (11)
C211.0092 (10)1.1076 (9)0.0154 (2)0.0572 (15)
H21A1.08391.14090.01220.086*
H21B1.10761.14120.03920.086*
H21C0.93921.18870.01830.086*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.029 (3)0.045 (3)0.028 (2)0.011 (2)0.002 (2)0.002 (2)
C20.041 (3)0.056 (3)0.033 (3)0.017 (3)0.013 (2)0.007 (3)
C30.056 (3)0.038 (3)0.025 (3)0.019 (3)0.002 (2)0.006 (2)
O30.071 (3)0.062 (3)0.028 (2)0.017 (2)0.0042 (19)0.0012 (18)
C40.043 (3)0.048 (3)0.027 (2)0.017 (3)0.009 (2)0.003 (2)
C50.031 (3)0.032 (3)0.035 (2)0.012 (2)0.002 (2)0.000 (2)
C60.023 (3)0.060 (4)0.040 (3)0.003 (3)0.002 (2)0.005 (3)
C70.022 (2)0.051 (3)0.036 (3)0.008 (2)0.002 (2)0.001 (2)
C80.016 (2)0.028 (2)0.035 (2)0.005 (2)0.0018 (19)0.0048 (19)
C90.021 (2)0.029 (2)0.023 (2)0.0100 (19)0.0001 (17)0.0045 (17)
C100.025 (2)0.032 (3)0.020 (2)0.011 (2)0.0025 (17)0.0005 (18)
C110.019 (2)0.030 (2)0.029 (2)0.006 (2)0.0029 (18)0.0038 (19)
O110.0204 (18)0.061 (3)0.0440 (19)0.0146 (17)0.0043 (15)0.0150 (18)
C120.025 (2)0.030 (2)0.031 (2)0.007 (2)0.001 (2)0.001 (2)
C130.022 (2)0.027 (2)0.027 (2)0.0122 (19)0.0017 (18)0.0032 (18)
C140.020 (2)0.028 (2)0.028 (2)0.010 (2)0.0019 (17)0.0102 (18)
C150.024 (2)0.043 (3)0.034 (3)0.012 (2)0.004 (2)0.004 (2)
C160.029 (3)0.040 (3)0.035 (3)0.015 (2)0.008 (2)0.006 (2)
C170.030 (2)0.025 (2)0.030 (2)0.016 (2)0.0090 (19)0.0098 (19)
O170.048 (2)0.039 (2)0.049 (2)0.0294 (18)0.0134 (17)0.0157 (17)
C180.033 (3)0.040 (3)0.033 (3)0.018 (2)0.005 (2)0.004 (2)
C190.050 (3)0.054 (3)0.038 (3)0.034 (3)0.001 (2)0.001 (2)
C200.036 (3)0.035 (3)0.040 (3)0.020 (2)0.011 (2)0.001 (2)
O200.073 (3)0.056 (3)0.032 (2)0.021 (2)0.0007 (19)0.0066 (19)
C210.056 (4)0.043 (3)0.062 (4)0.017 (3)0.001 (3)0.008 (3)
Geometric parameters (Å, º) top
C1—C21.526 (7)C12—C131.542 (6)
C1—C101.541 (6)C12—H12A0.9700
C1—H1A0.9700C12—H12B0.9700
C1—H1B0.9700C13—C181.539 (6)
C2—C31.508 (8)C13—C141.545 (6)
C2—H2A0.9700C13—C171.576 (6)
C2—H2B0.9700C14—C151.538 (6)
C3—O31.221 (6)C14—H140.9800
C3—C41.450 (8)C15—C161.537 (7)
C4—C51.348 (7)C15—H15A0.9700
C4—H40.9300C15—H15B0.9700
C5—C61.498 (7)C16—C171.559 (6)
C5—C101.531 (6)C16—H16A0.9700
C6—C71.482 (8)C16—H16B0.9700
C6—H6A0.9700C17—O171.435 (5)
C6—H6B0.9700C17—C201.536 (7)
C7—C81.525 (7)O17—H170.8200
C7—H7A0.9700C18—H18A0.9600
C7—H7B0.9700C18—H18B0.9600
C8—C141.525 (6)C18—H18C0.9600
C8—C91.561 (6)C19—H19A0.9600
C8—H80.9800C19—H19B0.9600
C9—C111.540 (6)C19—H19C0.9600
C9—C101.557 (6)C20—O201.212 (6)
C9—H90.9800C20—C211.500 (7)
C10—C191.555 (7)C21—H21A0.9600
C11—O111.214 (6)C21—H21B0.9600
C11—C121.531 (7)C21—H21C0.9600
C2—C1—C10114.0 (4)C13—C12—H12A110.0
C2—C1—H1A108.8C11—C12—H12B110.0
C10—C1—H1A108.8C13—C12—H12B110.0
C2—C1—H1B108.8H12A—C12—H12B108.4
C10—C1—H1B108.8C12—C13—C18108.7 (4)
H1A—C1—H1B107.6C12—C13—C14108.8 (3)
C3—C2—C1111.1 (4)C18—C13—C14112.4 (4)
C3—C2—H2A109.4C12—C13—C17116.2 (4)
C1—C2—H2A109.4C18—C13—C17110.6 (4)
C3—C2—H2B109.4C14—C13—C1799.9 (3)
C1—C2—H2B109.4C8—C14—C15118.0 (4)
H2A—C2—H2B108.0C8—C14—C13113.8 (3)
O3—C3—C4122.0 (5)C15—C14—C13103.2 (3)
O3—C3—C2122.6 (5)C8—C14—H14107.1
C4—C3—C2115.4 (4)C15—C14—H14107.1
C5—C4—C3125.0 (5)C13—C14—H14107.1
C5—C4—H4117.5C14—C15—C16104.4 (4)
C3—C4—H4117.5C14—C15—H15A110.9
C4—C5—C6121.3 (5)C16—C15—H15A110.9
C4—C5—C10122.2 (5)C14—C15—H15B110.9
C6—C5—C10116.5 (4)C16—C15—H15B110.9
C7—C6—C5113.9 (5)H15A—C15—H15B108.9
C7—C6—H6A108.8C15—C16—C17107.1 (4)
C5—C6—H6A108.8C15—C16—H16A110.3
C7—C6—H6B108.8C17—C16—H16A110.3
C5—C6—H6B108.8C15—C16—H16B110.3
H6A—C6—H6B107.7C17—C16—H16B110.3
C6—C7—C8114.0 (4)H16A—C16—H16B108.5
C6—C7—H7A108.7O17—C17—C20108.8 (4)
C8—C7—H7A108.7O17—C17—C16111.0 (4)
C6—C7—H7B108.7C20—C17—C16113.1 (4)
C8—C7—H7B108.7O17—C17—C13106.8 (3)
H7A—C7—H7B107.6C20—C17—C13114.6 (4)
C14—C8—C7111.1 (4)C16—C17—C13102.3 (3)
C14—C8—C9109.7 (4)C17—O17—H17109.5
C7—C8—C9109.2 (4)C13—C18—H18A109.5
C14—C8—H8109.0C13—C18—H18B109.5
C7—C8—H8109.0H18A—C18—H18B109.5
C9—C8—H8109.0C13—C18—H18C109.5
C11—C9—C10116.3 (3)H18A—C18—H18C109.5
C11—C9—C8110.5 (3)H18B—C18—H18C109.5
C10—C9—C8113.9 (4)C10—C19—H19A109.5
C11—C9—H9105.0C10—C19—H19B109.5
C10—C9—H9105.0H19A—C19—H19B109.5
C8—C9—H9105.0C10—C19—H19C109.5
C5—C10—C1110.0 (4)H19A—C19—H19C109.5
C5—C10—C19106.9 (4)H19B—C19—H19C109.5
C1—C10—C19110.8 (4)O20—C20—C21121.4 (5)
C5—C10—C9107.8 (4)O20—C20—C17120.6 (4)
C1—C10—C9109.9 (4)C21—C20—C17118.0 (5)
C19—C10—C9111.3 (4)C20—C21—H21A109.5
O11—C11—C12120.6 (4)C20—C21—H21B109.5
O11—C11—C9123.3 (4)H21A—C21—H21B109.5
C12—C11—C9116.1 (4)C20—C21—H21C109.5
C11—C12—C13108.4 (4)H21A—C21—H21C109.5
C11—C12—H12A110.0H21B—C21—H21C109.5
C10—C1—C2—C355.8 (6)C9—C11—C12—C1355.6 (5)
C1—C2—C3—O3147.9 (5)C11—C12—C13—C1865.9 (5)
C1—C2—C3—C435.7 (7)C11—C12—C13—C1456.8 (5)
O3—C3—C4—C5177.8 (6)C11—C12—C13—C17168.5 (4)
C2—C3—C4—C55.7 (8)C7—C8—C14—C1561.3 (5)
C3—C4—C5—C6172.0 (6)C9—C8—C14—C15177.9 (4)
C3—C4—C5—C106.4 (8)C7—C8—C14—C13177.6 (4)
C4—C5—C6—C7132.4 (5)C9—C8—C14—C1356.8 (5)
C10—C5—C6—C749.2 (7)C12—C13—C14—C861.1 (5)
C5—C6—C7—C850.0 (7)C18—C13—C14—C859.3 (5)
C6—C7—C8—C14173.5 (4)C17—C13—C14—C8176.6 (3)
C6—C7—C8—C952.4 (6)C12—C13—C14—C15169.9 (4)
C14—C8—C9—C1149.6 (5)C18—C13—C14—C1569.6 (5)
C7—C8—C9—C11171.6 (4)C17—C13—C14—C1547.6 (4)
C14—C8—C9—C10177.3 (4)C8—C14—C15—C16161.1 (4)
C7—C8—C9—C1055.3 (5)C13—C14—C15—C1634.8 (5)
C4—C5—C10—C112.6 (7)C14—C15—C16—C177.7 (5)
C6—C5—C10—C1168.9 (5)C15—C16—C17—O1792.3 (5)
C4—C5—C10—C19107.8 (5)C15—C16—C17—C20145.2 (4)
C6—C5—C10—C1970.6 (6)C15—C16—C17—C1321.4 (5)
C4—C5—C10—C9132.4 (5)C12—C13—C17—O1741.9 (5)
C6—C5—C10—C949.1 (6)C18—C13—C17—O17166.5 (4)
C2—C1—C10—C543.3 (6)C14—C13—C17—O1774.9 (4)
C2—C1—C10—C1974.8 (5)C12—C13—C17—C2078.6 (5)
C2—C1—C10—C9161.8 (4)C18—C13—C17—C2046.0 (5)
C11—C9—C10—C5177.0 (4)C14—C13—C17—C20164.6 (4)
C8—C9—C10—C552.7 (5)C12—C13—C17—C16158.6 (4)
C11—C9—C10—C157.1 (5)C18—C13—C17—C1676.8 (4)
C8—C9—C10—C1172.6 (4)C14—C13—C17—C1641.8 (4)
C11—C9—C10—C1966.0 (5)O17—C17—C20—O20155.5 (5)
C8—C9—C10—C1964.2 (5)C16—C17—C20—O2031.7 (6)
C10—C9—C11—O113.3 (6)C13—C17—C20—O2085.1 (5)
C8—C9—C11—O11128.6 (5)O17—C17—C20—C2126.2 (6)
C10—C9—C11—C12176.1 (4)C16—C17—C20—C21150.1 (4)
C8—C9—C11—C1252.0 (5)C13—C17—C20—C2193.2 (5)
O11—C11—C12—C13125.0 (5)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O17—H17···O3i0.822.343.094 (5)154
Symmetry code: (i) x+y+1, x+2, z1/3.

Experimental details

Crystal data
Chemical formulaC21H28O4
Mr344.43
Crystal system, space groupTrigonal, P31
Temperature (K)154
a, c (Å)7.297 (2), 30.304 (3)
V3)1397.4 (6)
Z3
Radiation typeMo Kα
µ (mm1)0.08
Crystal size (mm)0.45 × 0.34 × 0.28
Data collection
DiffractometerMARResearch image plate
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
6746, 1755, 1531
Rint0.059
(sin θ/λ)max1)0.609
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.065, 0.132, 1.19
No. of reflections1755
No. of parameters230
No. of restraints1
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.19, 0.21

Computer programs: Please provide missing details and reference, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), DIAMOND (Brandenburg, 2004), PLATON (Spek, 2003).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O17—H17···O3i0.822.343.094 (5)153.8
Symmetry code: (i) x+y+1, x+2, z1/3.
Endocyclic torsion angles about the ring junctions in (I) top
JunctionAtomsAngle (°)Characteristics
A/BC4-C5-C10-C1-12.6 (7)Quasi-trans
C6-C5-C10-C949.1 (6)
B/CC7-C8-C9-C1055.3 (5)Trans
C14-C8-C9-C11-49.6 (5)
C/DC12-C13-C14-C8-61.1 (5)Trans
C17-C13-C14-C1547.6 (4)
Functional groups of (I), with their orientations, distances from the C5–C17 mean plane (Å) and angles subtended at the C5–C17 mean plane (°) top
Functional groupOrientationDistanceAngle
C18β axial1.834 (5)4.6 (3)
C19β axial1.779 (6)7.0 (3)
O3α axial-1.854 (5)123.0 (4)
O11β equatorial0.804 (4)60.4 (3)
O17α axial-1.702 (4)170.4 (3)
O20β axial1.325 (5)31.6 (3)
C21α equatorial-0.436 (7)119.1 (3)
 

Acknowledgements

References

First citationBrandenburg, K. (2004). DIAMOND. Version 3. Crystal Impact GbR, Bonn, Germany.  Google Scholar
First citationBucourt, R. (1974). The Torsion Angle Concept in Conformational Analysis, in Topics in Stereochemistry, edited by E. L. Eliel & N. L. Allinger, Vol. 8, p. 159. New York: Interscience.  Google Scholar
First citationDuax, W. L., Griffin, J. F., Rohrer, D. C., Weeks, C. M. & Ebright, R. H. (1984). Biochemical Actions of Hormones, Vol. XI, pp. 187–205. New York: Academic Press.  Google Scholar
First citationDuax, W. L. & Norton, D. A. (1975). Atlas of Steroid Structures, Vol. 1, pp. 462–473. New York: Plenum.  Google Scholar
First citationGaldecki, Z., Grochulski, P., Wawrzak, Z. & Duax, W. L. (1989). J. Crystallogr. Spectrosc. Res. 19, 949–955.  CSD CrossRef CAS Web of Science Google Scholar
First citationKabsch, W. (1988). J. Appl. Cryst. 21, 916–932.  CrossRef CAS Web of Science IUCr Journals Google Scholar
First citationKlyne, W. & Prelog, V. (1960). Experientia, 16, 521–523.  CrossRef CAS Web of Science Google Scholar
First citationMickelson, K. E., Forsthoefel, J. & Westphal, U. (1981). Biochemistry, 20, 6211–6218.  CrossRef CAS PubMed Web of Science Google Scholar
First citationMurray, R. K., Granner, D. K., Mayes, P. A. & Rodwell, V. W. (1990). Harper's Biochemistry, 22nd ed., pp. 499–508. London: Prentice Hall International Inc.  Google Scholar
First citationSheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany.  Google Scholar
First citationSpek, A. L. (2003). J. Appl. Cryst. 36, 7–13.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationWestphal, U. (1983). J. Steroid Biochem. 19, 1–15.  CrossRef CAS PubMed Web of Science Google Scholar

© International Union of Crystallography. Prior permission is not required to reproduce short quotations, tables and figures from this article, provided the original authors and source are cited. For more information, click here.

Journal logoSTRUCTURAL
CHEMISTRY
ISSN: 2053-2296
Follow Acta Cryst. C
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds