5[beta],6[beta]-Ep­oxy-17-oxoandrostan-3[beta]-yl acetate and 5[beta],6[beta]-ep­oxy-20-oxo­pregnan-3[beta]-yl acetate

In the title compounds, C₂₁H₃₀O₄, (I), and C₂₃H₃₄O₄, (II), respectively, which are valuable inter­mediates in the synthesis of important steroid derivatives, rings A and B are cis-(5[beta],10[beta])-fused. The two mol­ecules have similar conformations of rings A, B and C. The presence of the 5[beta],6[beta]-epoxide group induces a significant twist of the steroid nucleus and a strong flattening of the B ring. The different C17 substituents result in different conformations for ring D. Cohesion of the mol­ecular packing is achieved in both compounds only by weak inter­molecular inter­actions. The geometries of the mol­ecules in the crystalline environment are compared with those of the free mol­ecules as given by ab initio Roothan Hartree-Fock calculations. We show in this work that quantum mechanical ab initio methods reproduce well the details of the conformation of these mol­ecules, including a large twist of the steroid nucleus. The calculated twist values are comparable, but are larger than the observed values, indicating a possible small effect of the crystal packing on the twist angles.

S1. Comment

The 5β,6β-epoxide functionality (Salvador et al., 2006) is present in several naturally occurring steroids, in which withanolides are a representative example. These compounds have been studied for anti-inflammatory (Jayaprakasam & Nair, 2003), antitumour (Kuroyanagi et al., 1999), cytotoxic (Veras et al., 2004) and immunomodulatory (Leyon & Kuttan, 2004) activities, as well as for cancer chemoprevention by inducing phase-II enzymes (Misico et al., 2002). Cytotoxic activity against several cell lines has been reported for other naturally occurring 5β,6β-epoxysteroids (Watanabe et al., 1996; Anta et al., 2002). 5β,6β-Epoxysteroids are also valuable intermediates for the synthesis of important compounds, such as brassinosteroid derivatives (Ramírez et al., 2000), laxogenin (Iglesias-Arteaga et al., 2005) and an analogue of squalamine (Cai & Zhou, 2004). In fact, the stereochemistry of these compounds rules their ring opening by nucleophilic agents, which leads to 5α-substituted-6β-hydroxysteroids (Pinto et al., 2006; Pinto, Salvador & Le Roux, 2007; Leitão et al., 2008). Recently, we reported the molecular structure of 5α-acetamido-6β-hydroxy-17-oxoandrostan-3β-yl acetate (Pinto, Ramos Silva et al., 2007) obtained from the reaction of the title compound, (I), with acetonitrile catalysed by BiBr₃ (Pinto et al., 2006). The title compounds, (I) and (II), were also used as substrates for the synthesis of new olefinic 18-nor and 18,19-dinorsteroids (Pinto et al., 2008). Thus, attending to the biological and synthetic importance of such molecules, we report here the molecular structures of the title 5β,6β-epoxysteroids, (I) and (II), determined by single-crystal X-ray diffraction, and compare them with those of the free molecules as given by quantum mechanical ab initio calculations.

The structures of compounds (I) and (II), with the corresponding atomic numbering schemes, are shown in Figs. 1 and 2. These two 5β,6β-epoxides are from different steroid series, (I) from androstane with a C17?O carbonyl group at ring D, and (II) from the pregnane series with a methyl ketone group at the side chain. In both molecules, the 3β-acetoxy group is equatorial to ring A, as is the 17β-COCH₃ group to ring D of (II).

Rings A and B are cis-(5β,10β)-fused [C1—C10—C5—C4 = -39,6(2)° in (I) and -37.9 (2)° in (II), and C9—C10—C5—C6 = 4.5 (2)° in (I) and 6.2 (3)° in (II)], with a bowing angle between the least-squares planes of rings A and B of 35.43 (9)° and 34.23 (9)° for (I) and (II), respectively.

The pseudo-torsion angle C19—C10···C13—C18 deviates largely from zero in both compounds [18.97 (17)° in (I) and 15.74 (17)° in (II)], showing that the steroid nucleus is significantly twisted. Comparably large pseudo-torsion angles have been observed in other 5β,6β-epoxysteroids (Hanson et al., 2003). This feature appears to be related to the presence of the 5β,6β-epoxide group, as it is absent in other cis-(5β,10β)-fused steroids without this functional group (Andrade et al., 2003; Andrade, Paixão, de Almeida, Tavares da Silva & Fernandes Roleira, 2005).

Average values for the atomic distances are in good agreement with reported ones (Allen et al., 1987), although for the Csp³—Csp³ bond lengths extreme values were found for C5—C6 [1.472 (3) Å in (I) and 1.464 (3) Å in (II)] and C9—C10 [1.567 (3) Å in (I) and 1.566 (2) Å in (II)], deviating significantly from the average values of 1.526 (3) and 1.528 (3) Å for compounds (I) and (II), respectively. Short C2—C3 bonds, common to other related steroids (Andrade, Paixão, de Almeida, Fernandes Roleira & Tavares da Silva, 2005), were also found [1.495 (3) Å in (I) and 1.499 (3) Å in (II)].

In both compounds, rings A and C have slightly flattened conformations intermediate between chair and half-chair, with average torsion angles of 51 (4) and 55 (2)°, respectively, for (I), and 52 (4) and 55 (2)°, respectively, for (II). Ring B of both 5β,6β-epoxysteroids adopts a strongly flattened conformation intermediate between half-chair and envelope, with Cremer & Pople (1975) parameters of Q = 0.5010 (19) Å, θ = 53.1 (2)° and ϕ = 190.7 (3)° for (I), and Q = 0.501 (2) Å, θ = 52.1 (2)° and ϕ = 193.1 (3)° for (II). In fact, as a consequence of the presence of the 5β,6β-epoxide group, atoms C7, C6, C5 and C10 are almost coplanar, as shown by the C7—C6—C5—C10 torsion angle of 1.2 (3)° in (I) and 0.5 (3)° in (II), which results in very low average torsion angles of 34 (10) and 38 (10)° for (I) and (II), respectively.

Ring D of (I) features a C14-envelope conformation, as shown by the Cremer & Pople parameters [q₂ = 0.424 (2) Å and ϕ₂ = 212.2 (3)°] and asymmetry parameters (Nardelli, 1983) [ΔC_s(14) = ΔC_s(16,17) = 3.4 (2)°]. In molecule (II), the five-membered ring D has a twisted conformation around the C13—C14 bond [q₂ = 0.463 (2) Å, ϕ₂ = 192.4 (3)° and ΔC₂(16) = Δ₂(13,14) = 6.6 (2)°].

Owing to the absence of any strong hydrogen donor, cohesion of the crystal structures of both compounds is mainly achieved by van der Waals and weak C—H···O interactions. In both structures, one weak C—H···O interaction between ring A and epoxide atom O5 links molecules along the a axis. In compound (II), another short contact is found between carbonyl atom O20 and an H atom of a neighbouring C21 methyl group. In addition, an intramolecular C—H···O interaction is present between the same carbonyl atom O20 and an H atom of ring D.

In order to gain some insight into how the crystal packing of (I) and (II) might affect the molecular geometry, and to check whether the large twist of the steroid nucleus is present in the isolated molecules, we have performed a quantum chemical calculation of the equilibrium geometry of the free molecules. These calculations were performed with the computer program GAMESS (Schmidt et al., 1993). A molecular orbital Roothan Hartree–Fock method was used with an extended 6-31G(d,p) basis set. Tight conditions for convergence of both the self-consistent field cycles and the maximum density and energy gradients were imposed (10^-5 atomic units). The programs were run on the Milipeia cluster of UC-LCA (16 Opteron cores, 2.2 GHz) running Linux.

Overall, there is very good agreement between the calculated and observed bond lengths, with the exception of the Csp³—O bond lengths of the epoxide group, where the calculated values were systematically shorter than the observed ones: for (I), O5—C5 calculated = 1.414 Å and experimental = 1.456 (2) Å, O5—C6 calculated = 1.407 Å and experimental = 1.435 (3) Å; for (II), O5—C5 calculated = 1.413 Å and experimental = 1.454 (2) Å, O5—C6 calculated = 1.407 Å and experimental = 1.429 (3) Å.

The calculated pseudo-torsion angles C19—C10···C13—C18 were significantly higher than the observed values for both compounds [calculated 22.7° and experimental 18.97 (17)° for (I), and calculated 22.2° and experimental 15.74 (17)° for (II)], showing that the crystal packing somehow affects the steroid nucleus. Interestingly, the calculations reproduce the short C5—C6 bond [calculated 1.459 Å and experimental 1.472 (3) Å for (I), and calculated 1.459 Å and experimental 1.464 (3) Å for (II)] and the long C9—C10 bond [calculated 1.574 Å and experimental 1.567 (3) Å for (I), and calculated 1.574 Å and experimental 1.566 (2) Å for (II)]. In both molecules, a shorter calculated value for the C3—O3A bond binding the 3β-acetoxy substituent to ring A is found [calculated 1.428 Å and experimental 1.462 (2) Å for (I), and calculated 1.429 Å and [experimental?] 1.464 (3) Å for (II)].

S2. Experimental

The synthesis of both epoxysteroids (I) and (II) was efficiently accomplished by epoxidation with KMnO₄/Fe₂(SO₄)₃.nH₂O (Salvador et al., 1996). Recrystallization from methanol at room temperature gave colourless single crystals suitable for X-ray analysis. Analytical data for compounds (I) and (II) are in accordance with the literature (Salvador et al., 1996).

S3. Refinement

All H atoms were refined as riding on their parent atoms, with C—H = 0.96–0.98 Å and with U_iso(H) = 1.2U_eq(C), or 1.5U_eq(C) for methyl H. [Please check added text] The absolute configuration was not determined from the X-ray data but was known from the synthetic route. Friedel pairs were merged before refinement.

Computing details

For both compounds, data collection: SMART (Bruker, 2003); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT (Bruker, 2003); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

	Fig. 1. The molecular structure of (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii.
	Fig. 2. The molecular structure of (II), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii.

(I) 5β,6β-Epoxy-17-oxoandrostan-3β-yl acetate

Crystal data

C21H30O4	Dx = 1.202 Mg m^−3
Mr = 346.45	Melting point: 462 K
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 8947 reflections
a = 5.8862 (1) Å	θ = 4.7–51.3°
b = 15.0988 (3) Å	µ = 0.08 mm^−1
c = 21.5413 (4) Å	T = 293 K
V = 1914.47 (6) Å^3	Long square prism, colourless
Z = 4	0.37 × 0.12 × 0.11 mm
F(000) = 752.0

Data collection

Bruker APEX CCD area-detector diffractometer	2609 independent reflections
Radiation source: fine-focus sealed tube	2155 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.029
ϕ and ω scans	θmax = 27.9°, θmin = 2.7°
Absorption correction: multi-scan (SADABS; Sheldrick, 2000)	h = −7→7
Tmin = 0.928, Tmax = 1.000	k = −19→19
62065 measured reflections	l = −27→27

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.040	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.123	H-atom parameters constrained
S = 1.02	w = 1/[σ^2(Fo^2) + (0.0805P)^2 + 0.1688P] where P = (Fo^2 + 2Fc^2)/3
2609 reflections	(Δ/σ)max < 0.001
229 parameters	Δρmax = 0.28 e Å^−3
0 restraints	Δρmin = −0.19 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
O3A	0.7278 (4)	0.80189 (9)	0.40926 (7)	0.0621 (5)
O3B	0.7562 (5)	0.83418 (13)	0.30919 (9)	0.0953 (8)
O5	0.4140 (2)	0.51801 (10)	0.34587 (7)	0.0513 (4)
O17	1.1917 (3)	0.10859 (11)	0.35421 (9)	0.0753 (5)
C1	0.9511 (4)	0.57417 (13)	0.43919 (10)	0.0477 (5)
H1A	1.0173	0.5481	0.4762	0.057*
H1B	1.0687	0.5759	0.4077	0.057*
C2	0.8816 (5)	0.66928 (13)	0.45424 (10)	0.0534 (5)
H2A	0.7686	0.6697	0.4870	0.064*
H2B	1.0125	0.7029	0.4682	0.064*
C3	0.7859 (4)	0.70952 (12)	0.39650 (9)	0.0476 (5)
H3	0.8995	0.7070	0.3633	0.057*
C3A	0.7214 (6)	0.85705 (15)	0.36172 (11)	0.0672 (7)
C3B	0.6595 (10)	0.94920 (16)	0.37946 (14)	0.1103 (16)
H21A	0.6748	0.9873	0.3440	0.166*
H21B	0.7587	0.9693	0.4119	0.166*
H21C	0.5053	0.9505	0.3939	0.166*
C4	0.5768 (4)	0.65952 (13)	0.37686 (11)	0.0499 (5)
H4A	0.5182	0.6854	0.3389	0.060*
H4B	0.4611	0.6659	0.4086	0.060*
C5	0.6218 (3)	0.56152 (12)	0.36615 (9)	0.0388 (4)
C6	0.5989 (4)	0.52584 (13)	0.30285 (9)	0.0450 (5)
H6	0.5795	0.5697	0.2697	0.054*
C7	0.7024 (4)	0.43955 (12)	0.28392 (8)	0.0460 (5)
H7A	0.8465	0.4507	0.2635	0.055*
H7B	0.6031	0.4104	0.2543	0.055*
C8	0.7411 (3)	0.37819 (11)	0.33939 (7)	0.0347 (4)
H8	0.5946	0.3593	0.3565	0.042*
C9	0.8783 (3)	0.42801 (11)	0.38948 (7)	0.0343 (4)
H9	1.0151	0.4497	0.3684	0.041*
C10	0.7582 (3)	0.51249 (12)	0.41608 (8)	0.0373 (4)
C11	0.9643 (4)	0.36572 (13)	0.44133 (9)	0.0485 (5)
H11A	1.0652	0.3987	0.4684	0.058*
H11B	0.8355	0.3465	0.4660	0.058*
C12	1.0894 (4)	0.28435 (14)	0.41742 (10)	0.0516 (5)
H12A	1.2289	0.3023	0.3970	0.062*
H12B	1.1287	0.2460	0.4519	0.062*
C13	0.9390 (3)	0.23451 (12)	0.37189 (9)	0.0398 (4)
C14	0.8763 (3)	0.29785 (12)	0.31871 (8)	0.0376 (4)
H14	1.0204	0.3207	0.3025	0.045*
C15	0.7810 (4)	0.23605 (14)	0.26826 (9)	0.0529 (5)
H15A	0.6260	0.2186	0.2775	0.063*
H15B	0.7853	0.2640	0.2277	0.063*
C16	0.9415 (5)	0.15704 (16)	0.27124 (11)	0.0622 (6)
H16A	1.0586	0.1621	0.2397	0.075*
H16B	0.8588	0.1023	0.2646	0.075*
C17	1.0466 (4)	0.15836 (14)	0.33588 (10)	0.0492 (5)
C18	0.7324 (4)	0.19280 (14)	0.40437 (10)	0.0548 (6)
H18A	0.6469	0.2382	0.4251	0.082*
H18B	0.7834	0.1500	0.4342	0.082*
H18C	0.6379	0.1642	0.3741	0.082*
C19	0.5945 (4)	0.49110 (16)	0.46942 (10)	0.0574 (6)
H19A	0.4893	0.4463	0.4563	0.086*
H19B	0.5125	0.5436	0.4808	0.086*
H19C	0.6793	0.4701	0.5045	0.086*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O3A	0.0990 (13)	0.0369 (7)	0.0506 (8)	0.0040 (9)	0.0091 (9)	−0.0042 (6)
O3B	0.148 (2)	0.0760 (12)	0.0618 (11)	0.0227 (16)	0.0193 (14)	0.0086 (9)
O5	0.0323 (6)	0.0533 (8)	0.0683 (9)	−0.0019 (6)	−0.0096 (7)	0.0008 (7)
O17	0.0753 (12)	0.0607 (10)	0.0900 (11)	0.0301 (9)	−0.0125 (10)	−0.0092 (9)
C1	0.0471 (11)	0.0460 (11)	0.0500 (10)	0.0022 (9)	−0.0117 (9)	−0.0097 (9)
C2	0.0619 (12)	0.0458 (11)	0.0524 (11)	0.0034 (10)	−0.0062 (11)	−0.0115 (9)
C3	0.0605 (12)	0.0364 (10)	0.0458 (10)	0.0004 (9)	0.0068 (10)	−0.0052 (8)
C3A	0.104 (2)	0.0448 (11)	0.0531 (13)	0.0018 (13)	0.0087 (14)	−0.0007 (10)
C3B	0.214 (5)	0.0443 (13)	0.0732 (16)	0.015 (2)	0.002 (3)	−0.0024 (12)
C4	0.0527 (12)	0.0407 (10)	0.0564 (12)	0.0081 (9)	−0.0054 (10)	0.0028 (9)
C5	0.0313 (8)	0.0384 (9)	0.0467 (9)	−0.0012 (7)	−0.0021 (8)	0.0040 (8)
C6	0.0474 (10)	0.0418 (10)	0.0458 (10)	0.0006 (9)	−0.0117 (9)	0.0079 (8)
C7	0.0574 (12)	0.0428 (10)	0.0380 (9)	−0.0012 (9)	−0.0081 (9)	0.0038 (8)
C8	0.0334 (8)	0.0367 (9)	0.0339 (8)	−0.0043 (7)	−0.0019 (7)	0.0031 (7)
C9	0.0320 (8)	0.0371 (9)	0.0338 (8)	−0.0012 (7)	−0.0018 (7)	0.0021 (7)
C10	0.0369 (9)	0.0382 (9)	0.0366 (8)	−0.0010 (8)	−0.0001 (7)	0.0027 (7)
C11	0.0617 (13)	0.0421 (10)	0.0418 (10)	0.0064 (10)	−0.0166 (10)	−0.0010 (8)
C12	0.0536 (12)	0.0466 (11)	0.0547 (11)	0.0094 (10)	−0.0168 (10)	0.0018 (9)
C13	0.0418 (10)	0.0362 (9)	0.0413 (9)	0.0035 (8)	0.0018 (8)	0.0019 (8)
C14	0.0380 (9)	0.0383 (9)	0.0365 (8)	−0.0032 (8)	0.0006 (8)	0.0020 (7)
C15	0.0648 (13)	0.0474 (11)	0.0464 (10)	0.0037 (11)	−0.0081 (10)	−0.0078 (9)
C16	0.0826 (17)	0.0519 (12)	0.0522 (12)	0.0094 (13)	0.0016 (12)	−0.0113 (10)
C17	0.0488 (11)	0.0419 (11)	0.0569 (12)	0.0029 (9)	0.0042 (10)	0.0007 (9)
C18	0.0627 (13)	0.0426 (10)	0.0593 (12)	−0.0004 (10)	0.0176 (12)	0.0106 (10)
C19	0.0593 (13)	0.0620 (13)	0.0511 (11)	0.0072 (12)	0.0169 (11)	0.0105 (10)

Geometric parameters (Å, º)

O3A—C3A	1.320 (3)	C8—C9	1.544 (2)
O3A—C3	1.462 (2)	C8—H8	0.9800
O3B—C3A	1.201 (3)	C9—C11	1.545 (2)
O5—C6	1.435 (3)	C9—C10	1.567 (3)
O5—C5	1.456 (2)	C9—H9	0.9800
O17—C17	1.204 (3)	C10—C19	1.534 (3)
C1—C2	1.528 (3)	C11—C12	1.522 (3)
C1—C10	1.551 (3)	C11—H11A	0.9700
C1—H1A	0.9700	C11—H11B	0.9700
C1—H1B	0.9700	C12—C13	1.520 (3)
C2—C3	1.495 (3)	C12—H12A	0.9700
C2—H2A	0.9700	C12—H12B	0.9700
C2—H2B	0.9700	C13—C17	1.525 (3)
C3—C4	1.505 (3)	C13—C14	1.537 (3)
C3—H3	0.9800	C13—C18	1.538 (3)
C3A—C3B	1.488 (4)	C14—C15	1.539 (3)
C3B—H21A	0.9600	C14—H14	0.9800
C3B—H21B	0.9600	C15—C16	1.523 (3)
C3B—H21C	0.9600	C15—H15A	0.9700
C4—C5	1.521 (3)	C15—H15B	0.9700
C4—H4A	0.9700	C16—C17	1.524 (3)
C4—H4B	0.9700	C16—H16A	0.9700
C5—C6	1.472 (3)	C16—H16B	0.9700
C5—C10	1.533 (2)	C18—H18A	0.9600
C6—C7	1.495 (3)	C18—H18B	0.9600
C6—H6	0.9800	C18—H18C	0.9600
C7—C8	1.529 (2)	C19—H19A	0.9600
C7—H7A	0.9700	C19—H19B	0.9600
C7—H7B	0.9700	C19—H19C	0.9600
C8—C14	1.518 (2)
C3A—O3A—C3	117.55 (16)	C11—C9—C10	112.26 (14)
C6—O5—C5	61.24 (12)	C8—C9—H9	105.6
C2—C1—C10	115.87 (19)	C11—C9—H9	105.6
C2—C1—H1A	108.3	C10—C9—H9	105.6
C10—C1—H1A	108.3	C5—C10—C19	107.38 (17)
C2—C1—H1B	108.3	C5—C10—C1	108.58 (14)
C10—C1—H1B	108.3	C19—C10—C1	110.24 (16)
H1A—C1—H1B	107.4	C5—C10—C9	111.89 (14)
C3—C2—C1	107.84 (17)	C19—C10—C9	112.71 (15)
C3—C2—H2A	110.1	C1—C10—C9	105.99 (15)
C1—C2—H2A	110.1	C12—C11—C9	113.90 (16)
C3—C2—H2B	110.1	C12—C11—H11A	108.8
C1—C2—H2B	110.1	C9—C11—H11A	108.8
H2A—C2—H2B	108.5	C12—C11—H11B	108.8
O3A—C3—C2	108.64 (15)	C9—C11—H11B	108.8
O3A—C3—C4	109.88 (19)	H11A—C11—H11B	107.7
C2—C3—C4	109.79 (18)	C13—C12—C11	109.64 (17)
O3A—C3—H3	109.5	C13—C12—H12A	109.7
C2—C3—H3	109.5	C11—C12—H12A	109.7
C4—C3—H3	109.5	C13—C12—H12B	109.7
O3B—C3A—O3A	123.0 (2)	C11—C12—H12B	109.7
O3B—C3A—C3B	123.5 (2)	H12A—C12—H12B	108.2
O3A—C3A—C3B	113.4 (2)	C12—C13—C17	117.37 (17)
C3A—C3B—H21A	109.5	C12—C13—C14	108.21 (15)
C3A—C3B—H21B	109.5	C17—C13—C14	100.94 (15)
H21A—C3B—H21B	109.5	C12—C13—C18	111.69 (17)
C3A—C3B—H21C	109.5	C17—C13—C18	104.54 (16)
H21A—C3B—H21C	109.5	C14—C13—C18	113.82 (17)
H21B—C3B—H21C	109.5	C8—C14—C13	113.86 (14)
C3—C4—C5	112.84 (18)	C8—C14—C15	120.04 (17)
C3—C4—H4A	109.0	C13—C14—C15	103.69 (15)
C5—C4—H4A	109.0	C8—C14—H14	106.1
C3—C4—H4B	109.0	C13—C14—H14	106.1
C5—C4—H4B	109.0	C15—C14—H14	106.1
H4A—C4—H4B	107.8	C16—C15—C14	102.64 (17)
O5—C5—C6	58.67 (12)	C16—C15—H15A	111.2
O5—C5—C4	109.76 (16)	C14—C15—H15A	111.2
C6—C5—C4	118.72 (17)	C16—C15—H15B	111.2
O5—C5—C10	115.64 (15)	C14—C15—H15B	111.2
C6—C5—C10	121.41 (16)	H15A—C15—H15B	109.2
C4—C5—C10	117.05 (17)	C15—C16—C17	106.27 (17)
O5—C6—C5	60.09 (12)	C15—C16—H16A	110.5
O5—C6—C7	114.43 (16)	C17—C16—H16A	110.5
C5—C6—C7	122.29 (16)	C15—C16—H16B	110.5
O5—C6—H6	116.0	C17—C16—H16B	110.5
C5—C6—H6	116.0	H16A—C16—H16B	108.7
C7—C6—H6	116.0	O17—C17—C16	125.4 (2)
C6—C7—C8	112.07 (16)	O17—C17—C13	126.8 (2)
C6—C7—H7A	109.2	C16—C17—C13	107.83 (18)
C8—C7—H7A	109.2	C13—C18—H18A	109.5
C6—C7—H7B	109.2	C13—C18—H18B	109.5
C8—C7—H7B	109.2	H18A—C18—H18B	109.5
H7A—C7—H7B	107.9	C13—C18—H18C	109.5
C14—C8—C7	109.46 (14)	H18A—C18—H18C	109.5
C14—C8—C9	108.67 (14)	H18B—C18—H18C	109.5
C7—C8—C9	109.20 (14)	C10—C19—H19A	109.5
C14—C8—H8	109.8	C10—C19—H19B	109.5
C7—C8—H8	109.8	H19A—C19—H19B	109.5
C9—C8—H8	109.8	C10—C19—H19C	109.5
C8—C9—C11	112.33 (14)	H19A—C19—H19C	109.5
C8—C9—C10	114.59 (14)	H19B—C19—H19C	109.5

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C1—H1B···O5^i	0.97	2.58	3.490 (3)	156

Symmetry code: (i) x+1, y, z.

(II) 5β,6β-Epoxy-20-oxopregnan-3β-yl acetate

Crystal data

C23H34O4	Dx = 1.189 Mg m^−3
Mr = 374.50	Melting point: 403 K
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 6859 reflections
a = 6.2955 (1) Å	θ = 2.8–24.7°
b = 11.8930 (1) Å	µ = 0.08 mm^−1
c = 27.9396 (4) Å	T = 293 K
V = 2091.90 (5) Å^3	Block, colourless
Z = 4	0.30 × 0.28 × 0.17 mm
F(000) = 816.0

Data collection

Bruker APEX CCD area-detector diffractometer	2940 independent reflections
Radiation source: fine-focus sealed tube	2530 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.025
ϕ and ω scans	θmax = 28.1°, θmin = 1.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 2000)	h = −8→8
Tmin = 0.955, Tmax = 1.000	k = −15→15
56880 measured reflections	l = −36→37

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.041	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.127	H-atom parameters constrained
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0734P)^2 + 0.2544P] where P = (Fo^2 + 2Fc^2)/3
2940 reflections	(Δ/σ)max = 0.002
248 parameters	Δρmax = 0.20 e Å^−3
0 restraints	Δρmin = −0.20 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
C1	0.9199 (3)	0.00374 (17)	0.10484 (8)	0.0512 (5)
H1A	0.9630	0.0197	0.0722	0.061*
H1B	1.0144	0.0450	0.1259	0.061*
C2	0.9510 (4)	−0.12158 (19)	0.11405 (8)	0.0571 (5)
H2A	0.8641	−0.1653	0.0923	0.068*
H2B	1.0985	−0.1421	0.1092	0.068*
C3	0.8870 (4)	−0.14441 (17)	0.16481 (8)	0.0525 (5)
H3	0.9713	−0.0979	0.1866	0.063*
O3A	0.9213 (3)	−0.26357 (13)	0.17542 (6)	0.0618 (4)
C3A	0.9611 (4)	−0.2899 (2)	0.22085 (9)	0.0622 (6)
O3B	0.9768 (5)	−0.22099 (19)	0.25216 (7)	0.0895 (7)
C3B	0.9740 (5)	−0.4140 (2)	0.22854 (11)	0.0777 (8)
H3BA	1.1088	−0.4411	0.2173	0.117*
H3BB	0.8619	−0.4504	0.2112	0.117*
H3BC	0.9598	−0.4302	0.2621	0.117*
C4	0.6534 (4)	−0.11915 (18)	0.17125 (8)	0.0546 (5)
H4A	0.6137	−0.1338	0.2042	0.066*
H4B	0.5712	−0.1691	0.1510	0.066*
C5	0.5991 (3)	0.00191 (16)	0.15888 (7)	0.0440 (4)
O5	0.3729 (2)	0.02051 (13)	0.16584 (6)	0.0551 (4)
C6	0.5202 (4)	0.07591 (18)	0.19680 (7)	0.0497 (5)
H6	0.5295	0.0459	0.2294	0.060*
C7	0.5220 (4)	0.20124 (17)	0.19269 (7)	0.0506 (5)
H7A	0.6459	0.2307	0.2091	0.061*
H7B	0.3967	0.2316	0.2082	0.061*
C8	0.5261 (3)	0.23920 (15)	0.14046 (6)	0.0394 (4)
H8	0.3912	0.2199	0.1250	0.047*
C9	0.7099 (3)	0.18047 (15)	0.11440 (6)	0.0405 (4)
H9	0.8367	0.1958	0.1337	0.049*
C10	0.6917 (3)	0.04926 (16)	0.11204 (7)	0.0411 (4)
C11	0.7542 (4)	0.23313 (18)	0.06511 (8)	0.0594 (6)
H11A	0.8837	0.2008	0.0523	0.071*
H11B	0.6391	0.2135	0.0436	0.071*
C12	0.7773 (4)	0.36164 (18)	0.06616 (8)	0.0571 (5)
H12A	0.9027	0.3818	0.0844	0.069*
H12B	0.7954	0.3895	0.0338	0.069*
C13	0.5819 (3)	0.41642 (16)	0.08871 (6)	0.0430 (4)
C14	0.5591 (3)	0.36612 (15)	0.13895 (6)	0.0420 (4)
H14	0.6940	0.3805	0.1553	0.050*
C15	0.3950 (5)	0.44052 (18)	0.16330 (8)	0.0611 (6)
H15A	0.4112	0.4384	0.1978	0.073*
H15B	0.2520	0.4172	0.1551	0.073*
C16	0.4432 (5)	0.55896 (19)	0.14354 (9)	0.0686 (7)
H16A	0.3141	0.5941	0.1319	0.082*
H16B	0.5034	0.6061	0.1684	0.082*
C17	0.6032 (4)	0.54363 (17)	0.10237 (7)	0.0548 (5)
H17	0.7460	0.5553	0.1154	0.066*
C18	0.3851 (5)	0.3996 (2)	0.05751 (8)	0.0647 (6)
H18A	0.4101	0.4309	0.0263	0.097*
H18B	0.2658	0.4366	0.0720	0.097*
H18C	0.3557	0.3207	0.0546	0.097*
C19	0.5469 (4)	0.00946 (18)	0.07137 (8)	0.0541 (5)
H19A	0.6131	0.0252	0.0412	0.081*
H19B	0.4133	0.0482	0.0732	0.081*
H19C	0.5234	−0.0700	0.0743	0.081*
C20	0.5726 (6)	0.6254 (2)	0.06142 (10)	0.0781 (8)
O20	0.4182 (6)	0.6851 (2)	0.05948 (10)	0.1422 (14)
C21	0.7391 (8)	0.6324 (2)	0.02447 (10)	0.1016 (13)
H21A	0.7164	0.5748	0.0009	0.152*
H21B	0.8758	0.6221	0.0390	0.152*
H21C	0.7337	0.7048	0.0093	0.152*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0457 (10)	0.0516 (11)	0.0564 (11)	0.0057 (9)	0.0086 (9)	0.0022 (9)
C2	0.0549 (12)	0.0532 (11)	0.0632 (12)	0.0106 (10)	0.0033 (11)	−0.0042 (10)
C3	0.0560 (12)	0.0422 (9)	0.0594 (12)	0.0049 (10)	−0.0048 (10)	−0.0009 (9)
O3A	0.0741 (11)	0.0475 (7)	0.0636 (9)	0.0124 (8)	−0.0062 (9)	0.0019 (7)
C3A	0.0522 (12)	0.0676 (14)	0.0667 (14)	0.0130 (11)	0.0020 (12)	0.0115 (11)
O3B	0.1167 (18)	0.0869 (13)	0.0648 (10)	0.0111 (14)	−0.0086 (12)	0.0028 (10)
C3B	0.0740 (17)	0.0721 (15)	0.0870 (18)	0.0229 (15)	0.0104 (16)	0.0225 (14)
C4	0.0584 (12)	0.0478 (10)	0.0577 (12)	0.0010 (10)	0.0030 (10)	0.0089 (9)
C5	0.0376 (9)	0.0473 (10)	0.0470 (10)	−0.0004 (8)	0.0008 (8)	0.0052 (8)
O5	0.0391 (7)	0.0613 (8)	0.0651 (9)	−0.0017 (7)	0.0070 (7)	0.0088 (7)
C6	0.0520 (11)	0.0569 (11)	0.0400 (9)	0.0043 (10)	0.0047 (9)	0.0091 (8)
C7	0.0620 (13)	0.0535 (10)	0.0365 (9)	0.0077 (10)	0.0083 (9)	0.0038 (8)
C8	0.0394 (9)	0.0448 (9)	0.0341 (8)	0.0012 (8)	0.0033 (7)	0.0006 (7)
C9	0.0368 (9)	0.0452 (9)	0.0396 (9)	−0.0005 (8)	0.0049 (8)	−0.0007 (7)
C10	0.0383 (9)	0.0460 (9)	0.0390 (8)	−0.0001 (8)	0.0005 (8)	−0.0005 (7)
C11	0.0763 (16)	0.0511 (11)	0.0509 (11)	0.0051 (11)	0.0282 (12)	0.0033 (9)
C12	0.0613 (13)	0.0513 (11)	0.0587 (12)	0.0008 (11)	0.0236 (11)	0.0080 (10)
C13	0.0458 (10)	0.0449 (9)	0.0382 (9)	−0.0011 (8)	0.0035 (8)	0.0025 (7)
C14	0.0461 (10)	0.0458 (9)	0.0341 (8)	0.0011 (8)	0.0000 (8)	−0.0009 (7)
C15	0.0811 (17)	0.0525 (11)	0.0498 (11)	0.0117 (12)	0.0193 (12)	0.0012 (9)
C16	0.0933 (19)	0.0514 (11)	0.0611 (13)	0.0133 (13)	0.0190 (14)	0.0033 (10)
C17	0.0666 (14)	0.0458 (10)	0.0521 (11)	0.0002 (11)	0.0041 (11)	0.0028 (8)
C18	0.0690 (15)	0.0722 (15)	0.0529 (12)	−0.0060 (13)	−0.0156 (12)	0.0082 (11)
C19	0.0583 (12)	0.0553 (11)	0.0486 (10)	−0.0059 (10)	−0.0062 (10)	−0.0030 (9)
C20	0.111 (2)	0.0506 (12)	0.0729 (16)	0.0077 (16)	0.0162 (17)	0.0149 (12)
O20	0.171 (3)	0.129 (2)	0.127 (2)	0.075 (2)	0.041 (2)	0.0736 (18)
C21	0.164 (4)	0.0633 (15)	0.0771 (17)	−0.006 (2)	0.047 (2)	0.0111 (13)

Geometric parameters (Å, º)

C1—C2	1.525 (3)	C9—H9	0.9800
C1—C10	1.548 (3)	C10—C19	1.532 (3)
C1—H1A	0.9700	C11—C12	1.536 (3)
C1—H1B	0.9700	C11—H11A	0.9700
C2—C3	1.499 (3)	C11—H11B	0.9700
C2—H2A	0.9700	C12—C13	1.528 (3)
C2—H2B	0.9700	C12—H12A	0.9700
C3—O3A	1.464 (3)	C12—H12B	0.9700
C3—C4	1.512 (3)	C13—C18	1.528 (3)
C3—H3	0.9800	C13—C14	1.533 (2)
O3A—C3A	1.331 (3)	C13—C17	1.566 (3)
C3A—O3B	1.202 (3)	C14—C15	1.521 (3)
C3A—C3B	1.494 (4)	C14—H14	0.9800
C3B—H3BA	0.9600	C15—C16	1.543 (3)
C3B—H3BB	0.9600	C15—H15A	0.9700
C3B—H3BC	0.9600	C15—H15B	0.9700
C4—C5	1.520 (3)	C16—C17	1.540 (3)
C4—H4A	0.9700	C16—H16A	0.9700
C4—H4B	0.9700	C16—H16B	0.9700
C5—O5	1.454 (2)	C17—C20	1.514 (3)
C5—C6	1.464 (3)	C17—H17	0.9800
C5—C10	1.540 (3)	C18—H18A	0.9600
O5—C6	1.429 (3)	C18—H18B	0.9600
C6—C7	1.495 (3)	C18—H18C	0.9600
C6—H6	0.9800	C19—H19A	0.9600
C7—C8	1.528 (2)	C19—H19B	0.9600
C7—H7A	0.9700	C19—H19C	0.9600
C7—H7B	0.9700	C20—O20	1.205 (4)
C8—C14	1.524 (3)	C20—C21	1.474 (4)
C8—C9	1.535 (3)	C21—H21A	0.9600
C8—H8	0.9800	C21—H21B	0.9600
C9—C11	1.538 (3)	C21—H21C	0.9600
C9—C10	1.566 (2)
C2—C1—C10	116.05 (18)	C5—C10—C1	109.51 (16)
C2—C1—H1A	108.3	C19—C10—C9	112.50 (16)
C10—C1—H1A	108.3	C5—C10—C9	110.89 (15)
C2—C1—H1B	108.3	C1—C10—C9	106.62 (16)
C10—C1—H1B	108.3	C12—C11—C9	113.91 (17)
H1A—C1—H1B	107.4	C12—C11—H11A	108.8
C3—C2—C1	107.58 (17)	C9—C11—H11A	108.8
C3—C2—H2A	110.2	C12—C11—H11B	108.8
C1—C2—H2A	110.2	C9—C11—H11B	108.8
C3—C2—H2B	110.2	H11A—C11—H11B	107.7
C1—C2—H2B	110.2	C13—C12—C11	110.86 (18)
H2A—C2—H2B	108.5	C13—C12—H12A	109.5
O3A—C3—C2	109.10 (17)	C11—C12—H12A	109.5
O3A—C3—C4	108.17 (19)	C13—C12—H12B	109.5
C2—C3—C4	109.77 (19)	C11—C12—H12B	109.5
O3A—C3—H3	109.9	H12A—C12—H12B	108.1
C2—C3—H3	109.9	C12—C13—C18	111.19 (17)
C4—C3—H3	109.9	C12—C13—C14	106.67 (17)
C3A—O3A—C3	116.63 (18)	C18—C13—C14	113.26 (17)
O3B—C3A—O3A	123.3 (2)	C12—C13—C17	116.35 (18)
O3B—C3A—C3B	124.3 (2)	C18—C13—C17	109.57 (18)
O3A—C3A—C3B	112.3 (2)	C14—C13—C17	99.32 (14)
C3A—C3B—H3BA	109.5	C15—C14—C8	118.12 (17)
C3A—C3B—H3BB	109.5	C15—C14—C13	104.27 (16)
H3BA—C3B—H3BB	109.5	C8—C14—C13	115.14 (15)
C3A—C3B—H3BC	109.5	C15—C14—H14	106.1
H3BA—C3B—H3BC	109.5	C8—C14—H14	106.1
H3BB—C3B—H3BC	109.5	C13—C14—H14	106.1
C3—C4—C5	112.33 (18)	C14—C15—C16	103.75 (19)
C3—C4—H4A	109.1	C14—C15—H15A	111.0
C5—C4—H4A	109.1	C16—C15—H15A	111.0
C3—C4—H4B	109.1	C14—C15—H15B	111.0
C5—C4—H4B	109.1	C16—C15—H15B	111.0
H4A—C4—H4B	107.9	H15A—C15—H15B	109.0
O5—C5—C6	58.65 (13)	C17—C16—C15	106.72 (18)
O5—C5—C4	109.51 (17)	C17—C16—H16A	110.4
C6—C5—C4	118.77 (17)	C15—C16—H16A	110.4
O5—C5—C10	115.40 (17)	C17—C16—H16B	110.4
C6—C5—C10	121.58 (16)	C15—C16—H16B	110.4
C4—C5—C10	117.05 (17)	H16A—C16—H16B	108.6
C6—O5—C5	61.03 (13)	C20—C17—C16	113.9 (2)
O5—C6—C5	60.32 (13)	C20—C17—C13	115.20 (19)
O5—C6—C7	114.72 (18)	C16—C17—C13	103.92 (18)
C5—C6—C7	122.76 (17)	C20—C17—H17	107.8
O5—C6—H6	115.7	C16—C17—H17	107.8
C5—C6—H6	115.7	C13—C17—H17	107.8
C7—C6—H6	115.7	C13—C18—H18A	109.5
C6—C7—C8	111.60 (16)	C13—C18—H18B	109.5
C6—C7—H7A	109.3	H18A—C18—H18B	109.5
C8—C7—H7A	109.3	C13—C18—H18C	109.5
C6—C7—H7B	109.3	H18A—C18—H18C	109.5
C8—C7—H7B	109.3	H18B—C18—H18C	109.5
H7A—C7—H7B	108.0	C10—C19—H19A	109.5
C14—C8—C7	108.75 (15)	C10—C19—H19B	109.5
C14—C8—C9	109.56 (15)	H19A—C19—H19B	109.5
C7—C8—C9	109.35 (15)	C10—C19—H19C	109.5
C14—C8—H8	109.7	H19A—C19—H19C	109.5
C7—C8—H8	109.7	H19B—C19—H19C	109.5
C9—C8—H8	109.7	O20—C20—C21	120.6 (3)
C8—C9—C11	112.08 (16)	O20—C20—C17	121.0 (3)
C8—C9—C10	114.71 (16)	C21—C20—C17	118.4 (3)
C11—C9—C10	112.42 (15)	C20—C21—H21A	109.5
C8—C9—H9	105.6	C20—C21—H21B	109.5
C11—C9—H9	105.6	H21A—C21—H21B	109.5
C10—C9—H9	105.6	C20—C21—H21C	109.5
C19—C10—C5	106.99 (16)	H21A—C21—H21C	109.5
C19—C10—C1	110.35 (17)	H21B—C21—H21C	109.5
C10—C1—C2—C3	−58.9 (3)	C2—C1—C10—C9	165.02 (17)
C1—C2—C3—O3A	−178.22 (18)	C8—C9—C10—C19	82.1 (2)
C1—C2—C3—C4	63.4 (2)	C11—C9—C10—C19	−47.6 (2)
C2—C3—O3A—C3A	152.2 (2)	C8—C9—C10—C5	−37.7 (2)
C4—C3—O3A—C3A	−88.4 (2)	C11—C9—C10—C5	−167.33 (18)
C3—O3A—C3A—O3B	−2.7 (4)	C8—C9—C10—C1	−156.86 (16)
C3—O3A—C3A—C3B	174.8 (2)	C11—C9—C10—C1	73.5 (2)
O3A—C3—C4—C5	−177.45 (16)	C8—C9—C11—C12	50.1 (3)
C2—C3—C4—C5	−58.5 (2)	C10—C9—C11—C12	−178.9 (2)
C3—C4—C5—O5	−179.98 (18)	C9—C11—C12—C13	−55.3 (3)
C3—C4—C5—C6	−115.8 (2)	C11—C12—C13—C18	−66.5 (2)
C3—C4—C5—C10	46.3 (3)	C11—C12—C13—C14	57.4 (2)
C4—C5—O5—C6	112.46 (19)	C11—C12—C13—C17	167.11 (18)
C10—C5—O5—C6	−112.93 (18)	C7—C8—C14—C15	−59.9 (2)
C5—O5—C6—C7	115.0 (2)	C9—C8—C14—C15	−179.40 (17)
C4—C5—C6—O5	−96.4 (2)	C7—C8—C14—C13	176.05 (17)
C10—C5—C6—O5	102.4 (2)	C9—C8—C14—C13	56.6 (2)
O5—C5—C6—C7	−101.9 (2)	C12—C13—C14—C15	168.17 (18)
C4—C5—C6—C7	161.7 (2)	C18—C13—C14—C15	−69.2 (2)
C10—C5—C6—C7	0.5 (3)	C17—C13—C14—C15	46.9 (2)
O5—C6—C7—C8	−46.2 (3)	C12—C13—C14—C8	−60.8 (2)
C5—C6—C7—C8	23.2 (3)	C18—C13—C14—C8	61.9 (2)
C6—C7—C8—C14	−172.16 (19)	C17—C13—C14—C8	177.97 (18)
C6—C7—C8—C9	−52.6 (2)	C8—C14—C15—C16	−165.32 (19)
C14—C8—C9—C11	−48.5 (2)	C13—C14—C15—C16	−36.1 (2)
C7—C8—C9—C11	−167.60 (18)	C14—C15—C16—C17	10.1 (3)
C14—C8—C9—C10	−178.27 (15)	C15—C16—C17—C20	144.8 (2)
C7—C8—C9—C10	62.6 (2)	C15—C16—C17—C13	18.6 (3)
O5—C5—C10—C19	−49.4 (2)	C12—C13—C17—C20	81.2 (3)
C6—C5—C10—C19	−116.8 (2)	C18—C13—C17—C20	−46.0 (3)
C4—C5—C10—C19	81.7 (2)	C14—C13—C17—C20	−164.9 (2)
O5—C5—C10—C1	−169.02 (17)	C12—C13—C17—C16	−153.5 (2)
C6—C5—C10—C1	123.6 (2)	C18—C13—C17—C16	79.3 (2)
C4—C5—C10—C1	−37.9 (2)	C14—C13—C17—C16	−39.6 (2)
O5—C5—C10—C9	73.6 (2)	C16—C17—C20—O20	−9.6 (4)
C6—C5—C10—C9	6.2 (3)	C13—C17—C20—O20	110.3 (3)
C4—C5—C10—C9	−155.30 (18)	C16—C17—C20—C21	168.9 (3)
C2—C1—C10—C19	−72.5 (2)	C13—C17—C20—C21	−71.1 (4)
C2—C1—C10—C5	45.0 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C1—H1B···O5^i	0.97	2.53	3.329 (3)	139
C16—H16A···O20	0.97	2.39	2.791 (3)	105
C21—H21C···O20^ii	0.96	2.60	3.389 (3)	140

Symmetry codes: (i) x+1, y, z; (ii) x+1/2, −y+3/2, −z.