5α-Androst-3-en-17β-yl acetate

Andrade, L.C.R.; Paixão, J.A.; Almeida, M.J.M. de; Tavares da Silva, E.J.; Fernandes Roleira, F.M.

doi:10.1107/S1600536809053264

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 66| Part 1| January 2010| Page o184

doi:10.1107/S1600536809053264

Open

access

5α-Androst-3-en-17β-yl acetate

L. C. R. Andrade,^a J. A. Paixão,^a ^* M. J. M. de Almeida,^a E. J. Tavares da Silva ^b and F. M. Fernandes Roleira ^b

^aCEMDRX, Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade de Coimbra, P-3004-516 Coimbra, Portugal, and ^bCentro de Estudos Farmacêuticos, Laboratório de Química Farmacêutica, Faculdade de Farmácia, Universidade de Coimbra, P-3000-295 Coimbra, Portugal
^*Correspondence e-mail: jap@pollux.fis.uc.pt

(Received 4 December 2009; accepted 10 December 2009; online 16 December 2009)

In the crystal structure of the title compound, C₂₁H₃₂O₂, ring A is highly distorted, with a conformation intermediate between 10β-sofa and 1α,10β-half chair; rings B and C have slightly flattened chair conformations. Ring D assumes an unusual 13β-envelope conformation, probably induced by the acetoxy substituent. Cohesion of the crystal structure is due only to weak van der Waals interactions.

Related literature

For structure–activity relationships (SAR) of steroids with modified A and D rings as aromatase inhibitors, see: Cepa et al. (2005 , 2008 ). For the synthesis and assignment of the absolute configuration, see: Cepa et al. (2008). For a related structure, see Paixão et al. (2001 ). For reference bond-length data, see: Allen et al. 1987 . For conformational details, see: Duax & Norton (1975 ); Cremer & Pople (1975 ); Altona et al. (1968 ).

Experimental

Crystal data

C₂₁H₃₂O₂
M_r = 316.47
Monoclinic, C 2
a = 14.7728 (3) Å
b = 6.2673 (1) Å
c = 20.2514 (5) Å
β = 99.874 (1)°
V = 1847.21 (7) Å³
Z = 4
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 293 K
0.41 × 0.39 × 0.10 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2000 ) T_min = 0.971, T_max = 0.993
22420 measured reflections
2292 independent reflections
1554 reflections with I > 2σ(I)
R_int = 0.030

Refinement

R[F² > 2σ(F²)] = 0.045
wR(F²) = 0.102
S = 1.08
2292 reflections
211 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.13 e Å⁻³
Δρ_min = −0.17 e Å⁻³

Data collection: APEX2 (Bruker, 2003 ); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEPII (Johnson, 1976 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809053264/wn2371sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809053264/wn2371Isup2.hkl

checkCIF report

Comment top

Following our interest in the study of structure-activity relationships (SAR) of steroids with modified A- and D-rings as aromatase inhibitors (Cepa et al., 2005), we have recently prepared and evaluated the title compound (Cepa et al., 2008), the 17-acetyl derivative of a potent aromatase inhibitor previously studied by X-ray diffraction (Paixão et al., 2001). In order to understand the role of specific D-ring substitution patterns in this inhibition process, its crystal structure was determined by single-crystal X-ray diffractometry.

Apart from the C6—C7 bond length, which is slightly shorter [1.511 (3) Å] than the average Csp³—Csp³ bond length in the molecule [1.53 (1) Å], bond lengths are well within reported values (Allen et al., 1987). Due to the C3═C4 double bond, ring A is highly distorted with a conformation intermediate between 10β-sofa and 1α,10β-half chair [(asymmetry parameters (Duax & Norton, 1975): ΔC_s(3)=8.9 (3), ΔC₂(3,4)=16.8 (4) and ΔC₂(1,2)=52.2 (4)°]. Rings B and C have slightly flattened chair conformations. Ring D assumes an unusual 13β-envelope conformation [puckering parameters (Cremer & Pople, 1975) q₂=0.477 (3)Å and ϕ₂=188.6 (4)°; pseudo-rotation (Altona et al., 1968) and asymmetry parameters (Duax & Norton, 1975): Δ=25.0 (4), ϕ_m=49.3 (2), ΔC_s(13)=5.8 (3), ΔC₂(13,14)=17.0 (3) and ΔC_s(14)=30.5 (3)°). The distance C3—O17B is 11.087 (3) Å. A pseudo-torsion C19—C10···C13—C18 angle of 3.3 (2)° indicates a slight twist of the molecule. The dihedral angle between the least-squares plane of ring D (C14···C17) and that of the four non-H atoms of the 17β acetate group is 69.2 (1)°. The structure lacks any strong hydrogen-bond donor; only weak van der Waals interactions can be responsible for the cohesion of the crystal structure.

Related literature top

For structure–activity relationships (SAR) of steroids with modified A and D rings as aromatase inhibitors, see: Cepa et al. (2005, 2008). For a related structure, see Paixão et al. (2001). For reference bond-length data, see: Allen et al. 1987. For conformational details, see: Duax & Norton (1975); Cremer & Pople (1975); Altona et al. (1968).

Experimental top

The title steroid was prepared according to the procedure previously reported (Cepa et al., 2008), yielding 95% of the pure compound as a white solid. Crystals suitable for X-ray studies were grown by slow evaporation from absolute ethanol. Mp 389–392 K.

Computing details top

Data collection: SMART (Bruker, 2003); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

Fig. 1. ORTEPII (Johnson, 1976) plot of the title compound. Displacement ellipsoids are drawn at the 50% probability level. Hydrogen atoms are shown as spheres of arbitrary radius.

5α-Androst-3-en-17β-yl acetate top

Crystal data top

C₂₁H₃₂O₂	F(000) = 696
M_r = 316.47	D_x = 1.138 Mg m⁻³
Monoclinic, C2	Mo Kα radiation, λ = 0.71073 Å
a = 14.7728 (3) Å	Cell parameters from 7585 reflections
b = 6.2673 (1) Å	θ = 2.8–21.5°
c = 20.2514 (5) Å	µ = 0.07 mm⁻¹
β = 99.874 (1)°	T = 293 K
V = 1847.21 (7) Å³	Prism, colourless
Z = 4	0.41 × 0.39 × 0.10 mm

Data collection top

Bruker APEXII CCD area-detector diffractometer	2292 independent reflections
Radiation source: fine-focus sealed tube	1554 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.030
ϕ and ω scans	θ_max = 27.9°, θ_min = 2.0°
Absorption correction: multi-scan (SADABS; Sheldrick, 2000)	h = −18→18
T_min = 0.971, T_max = 0.993	k = −8→8
22420 measured reflections	l = −26→25

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.045	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.102	H-atom parameters constrained
S = 1.08	w = 1/[σ²(F_o²) + (0.0455P)² + 0.3162P] where P = (F_o² + 2F_c²)/3
2292 reflections	(Δ/σ)_max < 0.001
211 parameters	Δρ_max = 0.13 e Å⁻³
1 restraint	Δρ_min = −0.17 e Å⁻³

Crystal data top

C₂₁H₃₂O₂	V = 1847.21 (7) Å³
M_r = 316.47	Z = 4
Monoclinic, C2	Mo Kα radiation
a = 14.7728 (3) Å	µ = 0.07 mm⁻¹
b = 6.2673 (1) Å	T = 293 K
c = 20.2514 (5) Å	0.41 × 0.39 × 0.10 mm
β = 99.874 (1)°

Data collection top

Bruker APEXII CCD area-detector diffractometer	2292 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 2000)	1554 reflections with I > 2σ(I)
T_min = 0.971, T_max = 0.993	R_int = 0.030
22420 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.045	1 restraint
wR(F²) = 0.102	H-atom parameters constrained
S = 1.08	Δρ_max = 0.13 e Å⁻³
2292 reflections	Δρ_min = −0.17 e Å⁻³
211 parameters

Special details top

Experimental. IR ν_max(KBr) cm^-1: 3015 (═C–H), 1733 (C═O); ¹H NMR (300 MHz, CDCl₃) δ: 0.77 (3H, s, 18-H₃)*, 0.79 (3H, s, 19-H₃)*, 2.03 (3H, s, CH₃COO), 4.59 (1H, dd, J₁₇_α_,16_α=7.9, J₁₇_α_,16_β=7.9, 17α-H), 5.27 (1H, ddd, J_4,3=9.8, J_4,5_α=4.5, J_4,2_α=2.5, 4-H), 5.54 (1H, ddd, J_3,4=9.8, J_3,2_β=6.3, J_3,2_α=3.2, 3-H); ¹³C NMR (75.6 MHz, DMSO-d₆) δ: 11.8 (C-19)**, 12.2 (C-18)**, 20.5, 21.1, 23.4, 23.5, 27.2, 27.5, 31.5, 34.1, 34.9, 35.3, 36.9, 42.7, 45.8 (C-5), 50.7, 53.3, 82.9 (C-17), 125.4 (C-3), 131.2 (C-4); 171.2 (C═O); EIMS m/z 316 (M⁺, 100%). *,** Signals may be interchangeable.

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

	x	y	z	U_iso*/U_eq
C1	0.19131 (17)	0.6621 (5)	0.62336 (12)	0.0534 (7)
H1A	0.1677	0.7480	0.6565	0.064*
H1B	0.2252	0.7558	0.5983	0.064*
C2	0.11018 (18)	0.5657 (6)	0.57530 (14)	0.0724 (9)
H2A	0.0626	0.5259	0.6006	0.087*
H2B	0.0848	0.6733	0.5429	0.087*
C3	0.13589 (19)	0.3740 (5)	0.53863 (13)	0.0633 (8)
H3	0.0923	0.3151	0.5050	0.076*
C4	0.21769 (18)	0.2854 (5)	0.55206 (12)	0.0525 (7)
H4	0.2288	0.1648	0.5279	0.063*
C5	0.29364 (15)	0.3678 (4)	0.60392 (11)	0.0428 (6)
H5	0.3265	0.4721	0.5808	0.051*
C6	0.36450 (17)	0.2002 (4)	0.63145 (13)	0.0508 (7)
H6A	0.3366	0.0950	0.6568	0.061*
H6B	0.3858	0.1278	0.5946	0.061*
C7	0.44506 (15)	0.3031 (4)	0.67622 (12)	0.0480 (7)
H7A	0.4773	0.3944	0.6493	0.058*
H7B	0.4873	0.1928	0.6958	0.058*
C8	0.41595 (15)	0.4351 (4)	0.73221 (11)	0.0385 (6)
H8	0.3911	0.3380	0.7626	0.046*
C9	0.34047 (14)	0.5989 (4)	0.70474 (10)	0.0353 (5)
H9	0.3681	0.6951	0.6756	0.042*
C10	0.25731 (14)	0.4943 (4)	0.65963 (11)	0.0394 (6)
C11	0.31613 (15)	0.7380 (4)	0.76137 (11)	0.0434 (6)
H11A	0.2728	0.8468	0.7421	0.052*
H11B	0.2860	0.6500	0.7905	0.052*
C12	0.39942 (15)	0.8466 (4)	0.80345 (11)	0.0429 (6)
H12A	0.4253	0.9487	0.7759	0.052*
H12B	0.3800	0.9237	0.8401	0.052*
C13	0.47280 (15)	0.6831 (4)	0.83163 (11)	0.0378 (6)
C14	0.49663 (14)	0.5547 (4)	0.77246 (11)	0.0399 (6)
H14	0.5161	0.6592	0.7417	0.048*
C15	0.58350 (16)	0.4311 (5)	0.80303 (13)	0.0599 (8)
H15A	0.6212	0.4002	0.7694	0.072*
H15B	0.5679	0.2981	0.8229	0.072*
C16	0.63351 (16)	0.5840 (5)	0.85708 (13)	0.0572 (7)
H16A	0.6450	0.5148	0.9006	0.069*
H16B	0.6917	0.6301	0.8458	0.069*
C17	0.56810 (15)	0.7744 (4)	0.85757 (12)	0.0447 (6)
H17	0.5826	0.8834	0.8263	0.054*
C18	0.44041 (17)	0.5428 (5)	0.88509 (12)	0.0530 (7)
H18A	0.4859	0.4358	0.8998	0.080*
H18B	0.3835	0.4751	0.8664	0.080*
H18C	0.4316	0.6296	0.9225	0.080*
C19	0.20421 (17)	0.3490 (5)	0.70079 (13)	0.0562 (7)
H19A	0.1693	0.4350	0.7265	0.084*
H19B	0.2468	0.2625	0.7305	0.084*
H19C	0.1634	0.2587	0.6711	0.084*
C17A	0.64397 (18)	0.9967 (5)	0.94474 (13)	0.0538 (7)
C17B	0.6399 (2)	1.0837 (7)	1.01266 (14)	0.0876 (11)
H17B	0.5804	1.0557	1.0238	0.131*
H17C	0.6505	1.2348	1.0129	0.131*
H17D	0.6862	1.0165	1.0450	0.131*
O17A	0.57234 (11)	0.8688 (3)	0.92319 (8)	0.0531 (5)
O17B	0.70289 (13)	1.0344 (4)	0.91272 (10)	0.0760 (7)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0468 (15)	0.0607 (18)	0.0501 (15)	0.0143 (13)	0.0005 (13)	−0.0053 (14)
C2	0.0503 (16)	0.094 (2)	0.0664 (19)	0.0145 (18)	−0.0084 (15)	−0.021 (2)
C3	0.0517 (17)	0.085 (2)	0.0500 (16)	−0.0041 (17)	−0.0007 (13)	−0.0134 (17)
C4	0.0549 (16)	0.0559 (16)	0.0456 (15)	−0.0013 (14)	0.0061 (13)	−0.0085 (13)
C5	0.0421 (13)	0.0468 (14)	0.0400 (13)	0.0028 (13)	0.0082 (11)	0.0007 (12)
C6	0.0507 (16)	0.0492 (15)	0.0520 (15)	0.0099 (13)	0.0074 (13)	−0.0120 (13)
C7	0.0422 (14)	0.0486 (15)	0.0530 (15)	0.0155 (12)	0.0072 (12)	−0.0062 (13)
C8	0.0365 (12)	0.0400 (13)	0.0394 (13)	0.0057 (11)	0.0079 (10)	0.0030 (11)
C9	0.0356 (12)	0.0359 (13)	0.0354 (12)	0.0034 (11)	0.0085 (10)	0.0034 (11)
C10	0.0324 (12)	0.0456 (14)	0.0399 (13)	0.0033 (11)	0.0059 (10)	0.0007 (11)
C11	0.0379 (13)	0.0472 (16)	0.0437 (14)	0.0117 (12)	0.0028 (11)	−0.0036 (12)
C12	0.0437 (14)	0.0432 (14)	0.0421 (13)	0.0076 (12)	0.0079 (11)	−0.0051 (12)
C13	0.0327 (12)	0.0441 (14)	0.0367 (13)	0.0037 (10)	0.0063 (10)	0.0037 (11)
C14	0.0325 (12)	0.0421 (14)	0.0452 (13)	0.0073 (11)	0.0074 (10)	0.0029 (12)
C15	0.0391 (14)	0.070 (2)	0.0666 (18)	0.0160 (14)	−0.0019 (13)	−0.0073 (16)
C16	0.0378 (13)	0.073 (2)	0.0582 (16)	0.0059 (15)	0.0001 (12)	0.0014 (16)
C17	0.0382 (13)	0.0567 (15)	0.0389 (14)	−0.0024 (12)	0.0059 (11)	0.0019 (12)
C18	0.0490 (15)	0.0644 (17)	0.0459 (15)	−0.0046 (14)	0.0087 (12)	0.0078 (14)
C19	0.0474 (14)	0.0678 (18)	0.0556 (15)	−0.0138 (14)	0.0148 (12)	−0.0053 (15)
C17A	0.0412 (15)	0.0629 (18)	0.0527 (17)	−0.0044 (14)	−0.0049 (13)	0.0013 (14)
C17B	0.070 (2)	0.124 (3)	0.0644 (19)	−0.028 (2)	0.0012 (15)	−0.027 (2)
O17A	0.0442 (10)	0.0721 (12)	0.0418 (9)	−0.0114 (10)	0.0045 (7)	−0.0088 (10)
O17B	0.0516 (11)	0.1011 (17)	0.0758 (14)	−0.0238 (13)	0.0125 (10)	−0.0063 (13)

Geometric parameters (Å, º) top

C1—C2	1.533 (3)	C11—H11B	0.9700
C1—C10	1.533 (3)	C12—C13	1.529 (3)
C1—H1A	0.9700	C12—H12A	0.9700
C1—H1B	0.9700	C12—H12B	0.9700
C2—C3	1.495 (4)	C13—C17	1.527 (3)
C2—H2A	0.9700	C13—C18	1.534 (3)
C2—H2B	0.9700	C13—C14	1.534 (3)
C3—C4	1.315 (3)	C14—C15	1.536 (3)
C3—H3	0.9300	C14—H14	0.9800
C4—C5	1.491 (3)	C15—C16	1.545 (4)
C4—H4	0.9300	C15—H15A	0.9700
C5—C6	1.520 (3)	C15—H15B	0.9700
C5—C10	1.548 (3)	C16—C17	1.536 (4)
C5—H5	0.9800	C16—H16A	0.9700
C6—C7	1.511 (3)	C16—H16B	0.9700
C6—H6A	0.9700	C17—O17A	1.446 (3)
C6—H6B	0.9700	C17—H17	0.9800
C7—C8	1.524 (3)	C18—H18A	0.9600
C7—H7A	0.9700	C18—H18B	0.9600
C7—H7B	0.9700	C18—H18C	0.9600
C8—C14	1.521 (3)	C19—H19A	0.9600
C8—C9	1.547 (3)	C19—H19B	0.9600
C8—H8	0.9800	C19—H19C	0.9600
C9—C11	1.532 (3)	C17A—O17B	1.195 (3)
C9—C10	1.546 (3)	C17A—O17A	1.340 (3)
C9—H9	0.9800	C17A—C17B	1.490 (4)
C10—C19	1.538 (3)	C17B—H17B	0.9600
C11—C12	1.531 (3)	C17B—H17C	0.9600
C11—H11A	0.9700	C17B—H17D	0.9600

C2—C1—C10	113.4 (2)	H11A—C11—H11B	107.7
C2—C1—H1A	108.9	C13—C12—C11	111.2 (2)
C10—C1—H1A	108.9	C13—C12—H12A	109.4
C2—C1—H1B	108.9	C11—C12—H12A	109.4
C10—C1—H1B	108.9	C13—C12—H12B	109.4
H1A—C1—H1B	107.7	C11—C12—H12B	109.4
C3—C2—C1	113.2 (2)	H12A—C12—H12B	108.0
C3—C2—H2A	108.9	C17—C13—C12	115.5 (2)
C1—C2—H2A	108.9	C17—C13—C18	110.66 (18)
C3—C2—H2B	108.9	C12—C13—C18	111.13 (19)
C1—C2—H2B	108.9	C17—C13—C14	98.27 (17)
H2A—C2—H2B	107.7	C12—C13—C14	107.64 (17)
C4—C3—C2	122.6 (3)	C18—C13—C14	113.1 (2)
C4—C3—H3	118.7	C8—C14—C13	114.43 (17)
C2—C3—H3	118.7	C8—C14—C15	119.4 (2)
C3—C4—C5	123.6 (3)	C13—C14—C15	103.75 (18)
C3—C4—H4	118.2	C8—C14—H14	106.1
C5—C4—H4	118.2	C13—C14—H14	106.1
C4—C5—C6	114.0 (2)	C15—C14—H14	106.1
C4—C5—C10	112.18 (18)	C14—C15—C16	103.8 (2)
C6—C5—C10	112.93 (18)	C14—C15—H15A	111.0
C4—C5—H5	105.6	C16—C15—H15A	111.0
C6—C5—H5	105.6	C14—C15—H15B	111.0
C10—C5—H5	105.6	C16—C15—H15B	111.0
C7—C6—C5	110.3 (2)	H15A—C15—H15B	109.0
C7—C6—H6A	109.6	C17—C16—C15	105.17 (18)
C5—C6—H6A	109.6	C17—C16—H16A	110.7
C7—C6—H6B	109.6	C15—C16—H16A	110.7
C5—C6—H6B	109.6	C17—C16—H16B	110.7
H6A—C6—H6B	108.1	C15—C16—H16B	110.7
C6—C7—C8	112.61 (19)	H16A—C16—H16B	108.8
C6—C7—H7A	109.1	O17A—C17—C13	111.19 (17)
C8—C7—H7A	109.1	O17A—C17—C16	113.30 (19)
C6—C7—H7B	109.1	C13—C17—C16	104.5 (2)
C8—C7—H7B	109.1	O17A—C17—H17	109.2
H7A—C7—H7B	107.8	C13—C17—H17	109.2
C14—C8—C7	111.78 (18)	C16—C17—H17	109.2
C14—C8—C9	108.42 (18)	C13—C18—H18A	109.5
C7—C8—C9	111.75 (17)	C13—C18—H18B	109.5
C14—C8—H8	108.3	H18A—C18—H18B	109.5
C7—C8—H8	108.3	C13—C18—H18C	109.5
C9—C8—H8	108.3	H18A—C18—H18C	109.5
C11—C9—C10	114.78 (17)	H18B—C18—H18C	109.5
C11—C9—C8	110.83 (16)	C10—C19—H19A	109.5
C10—C9—C8	112.44 (17)	C10—C19—H19B	109.5
C11—C9—H9	106.0	H19A—C19—H19B	109.5
C10—C9—H9	106.0	C10—C19—H19C	109.5
C8—C9—H9	106.0	H19A—C19—H19C	109.5
C1—C10—C19	108.93 (19)	H19B—C19—H19C	109.5
C1—C10—C9	111.59 (19)	O17B—C17A—O17A	123.3 (3)
C19—C10—C9	111.01 (18)	O17B—C17A—C17B	125.3 (3)
C1—C10—C5	105.87 (18)	O17A—C17A—C17B	111.4 (2)
C19—C10—C5	111.4 (2)	C17A—C17B—H17B	109.5
C9—C10—C5	107.95 (16)	C17A—C17B—H17C	109.5
C12—C11—C9	113.60 (18)	H17B—C17B—H17C	109.5
C12—C11—H11A	108.8	C17A—C17B—H17D	109.5
C9—C11—H11A	108.8	H17B—C17B—H17D	109.5
C12—C11—H11B	108.8	H17C—C17B—H17D	109.5
C9—C11—H11B	108.8	C17A—O17A—C17	116.84 (19)

C10—C1—C2—C3	−37.9 (3)	C9—C11—C12—C13	−55.1 (3)
C1—C2—C3—C4	6.9 (4)	C11—C12—C13—C17	163.78 (18)
C2—C3—C4—C5	−1.2 (5)	C11—C12—C13—C18	−69.1 (2)
C3—C4—C5—C6	155.6 (3)	C11—C12—C13—C14	55.2 (2)
C3—C4—C5—C10	25.7 (4)	C7—C8—C14—C13	−177.5 (2)
C4—C5—C6—C7	172.2 (2)	C9—C8—C14—C13	58.9 (2)
C10—C5—C6—C7	−58.2 (3)	C7—C8—C14—C15	−53.7 (3)
C5—C6—C7—C8	54.7 (3)	C9—C8—C14—C15	−177.28 (19)
C6—C7—C8—C14	−174.4 (2)	C17—C13—C14—C8	179.97 (19)
C6—C7—C8—C9	−52.7 (3)	C12—C13—C14—C8	−59.9 (2)
C14—C8—C9—C11	−53.2 (2)	C18—C13—C14—C8	63.3 (2)
C7—C8—C9—C11	−176.8 (2)	C17—C13—C14—C15	48.1 (2)
C14—C8—C9—C10	176.82 (17)	C12—C13—C14—C15	168.3 (2)
C7—C8—C9—C10	53.2 (2)	C18—C13—C14—C15	−68.6 (2)
C2—C1—C10—C19	−60.0 (3)	C8—C14—C15—C16	−162.0 (2)
C2—C1—C10—C9	177.1 (2)	C13—C14—C15—C16	−33.2 (2)
C2—C1—C10—C5	59.9 (3)	C14—C15—C16—C17	4.6 (3)
C11—C9—C10—C1	61.9 (2)	C12—C13—C17—O17A	78.3 (3)
C8—C9—C10—C1	−170.18 (18)	C18—C13—C17—O17A	−49.0 (3)
C11—C9—C10—C19	−59.8 (3)	C14—C13—C17—O17A	−167.57 (19)
C8—C9—C10—C19	68.1 (2)	C12—C13—C17—C16	−159.1 (2)
C11—C9—C10—C5	177.85 (19)	C18—C13—C17—C16	73.6 (2)
C8—C9—C10—C5	−54.2 (2)	C14—C13—C17—C16	−45.0 (2)
C4—C5—C10—C1	−52.5 (3)	C15—C16—C17—O17A	146.8 (2)
C6—C5—C10—C1	177.1 (2)	C15—C16—C17—C13	25.6 (3)
C4—C5—C10—C19	65.8 (3)	O17B—C17A—O17A—C17	−0.1 (4)
C6—C5—C10—C19	−64.7 (2)	C17B—C17A—O17A—C17	179.8 (2)
C4—C5—C10—C9	−172.1 (2)	C13—C17—O17A—C17A	−164.9 (2)
C6—C5—C10—C9	57.5 (2)	C16—C17—O17A—C17A	77.7 (3)
C10—C9—C11—C12	−177.70 (18)	C19—C10—C13—C18	3.33 (19)
C8—C9—C11—C12	53.6 (2)

Experimental details

Crystal data
Chemical formula	C₂₁H₃₂O₂
M_r	316.47
Crystal system, space group	Monoclinic, C2
Temperature (K)	293
a, b, c (Å)	14.7728 (3), 6.2673 (1), 20.2514 (5)
β (°)	99.874 (1)
V (Å³)	1847.21 (7)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.07
Crystal size (mm)	0.41 × 0.39 × 0.10

Data collection
Diffractometer	Bruker APEXII CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 2000)
T_min, T_max	0.971, 0.993
No. of measured, independent and observed [I > 2σ(I)] reflections	22420, 2292, 1554
R_int	0.030
(sin θ/λ)_max (Å⁻¹)	0.659

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.045, 0.102, 1.08
No. of reflections	2292
No. of parameters	211
No. of restraints	1
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.13, −0.17

Computer programs: SMART (Bruker, 2003), SAINT (Bruker, 2003), SAINT, SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEPII (Johnson, 1976).

Acknowledgements

This work was supported by Fundação para a Ciência e Tecnologia.

References

Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19. CrossRef Web of Science Google Scholar
Altona, C., Geise, H. J. & Romers, C. (1968). Tetrahedron, 24, 13–32. CrossRef CAS Web of Science Google Scholar
Bruker (2003). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Cepa, M. M. D. S., Tavares da Silva, E. J., Correia-da-Silva, G., Roleira, F. M. & Teixeira, N. A. A. (2005). J. Med. Chem. 48, 6379–6385. Web of Science CrossRef PubMed CAS Google Scholar
Cepa, M. M. D. S., Tavares da Silva, E. J., Correia-da-Silva, G., Roleira, F. M. & Teixeira, N. A. A. (2008). Steroids, 73, 1409–1415. Web of Science CrossRef PubMed CAS Google Scholar
Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354–1358. CrossRef CAS Web of Science Google Scholar
Duax, W. L. & Norton, D. A. (1975). In Atlas of Steroids Structure, Vol. 1. New York: Plenum. Google Scholar
Johnson, C. K. (1976). ORTEPII. Report ORNL-5138. Oak Ridge National Laboratory, Tennessee, USA. Google Scholar
Paixão, J. A., Andrade, L. C. R., Almeida, M. J. M., Tavares da Silva, E. J., Roleira, F. M., Sá e Melo, M. L. & Campos Neves, A. S. (2001). Acta Cryst. E57, o189–o191. Google Scholar
Sheldrick, G. M. (2000). SADABS. Universiry of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar