16α-Hydro­xy-20-oxopregn-5-en-3β-yl acetate

Andrade, L.C.R.; Paixão, J.A.; Almeida, M.J.M. de; Martins, R.M.L.M.; Soares, H.I.M.; Moreno, M.J.S.M.; Sá e Melo, M.L.; Campos Neves, A.S.

doi:10.1107/S1600536801008996

16α-Hydroxy-20-oxopregn-5-en-3β-yl acetate

L. C. R. Andrade, J. A. Paixão, M. J. M. de Almeida, R. M. L. M. Martins, H. I. M. Soares, M. J. S. M. Moreno, M. L. Sá e Melo and A. S. Campos Neves

In the title compound, C₂₃H₃₄O₄, the two saturated six-membered rings have slightly flattened chair conformations and the unsaturated ring assumes a 8β,9α-half chair conformation distorted towards a 8β-sofa. The five-membered ring has an unusual conformation close to a 13β-envelope. The acetoxy and methyl ketone substituents are twisted with respect to the average molecular plane of the steroid nucleus. The molecules are hydrogen-bonded head-to-head via the hydroxy and methyl ketone groups forming dimers, which are stacked in planes perpendicular to the b axis.

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Supporting information

	Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536801008996/cv6029sup1.cif Contains datablocks I, global
	Structure factor file (CIF format) https://doi.org/10.1107/S1600536801008996/cv6029Isup2.hkl Contains datablock I

CCDC reference: 170755

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Key indicators

Single-crystal X-ray study
T = 293 K
Mean (C-C) = 0.004 Å
R factor = 0.041
wR factor = 0.119
Data-to-parameter ratio = 10.1

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No syntax errors found

ADDSYM reports no extra symmetry

General Notes



REFLT_03
         From the CIF: _diffrn_reflns_theta_max           27.47
         From the CIF: _reflns_number_total               2553
         Count of symmetry unique reflns         2612
         Completeness (_total/calc)             97.74%
         TEST3: Check Friedels for noncentro structure
         Estimate of Friedel pairs measured         0
         Fraction of Friedel pairs measured     0.000
         Are heavy atom types Z>Si present           no
          Please check that the estimate of the number of Friedel pairs is
          correct. If it is not, please give the correct count in the
          _publ_section_exptl_refinement section of the submitted CIF.

Comment top

As part of an ongoing project to clarify the behaviour of steroidal 16α,17α-epoxy ketones towards reactions with broad scope in the synthesis of bioactive steroids (Moreno, Costa et al., 1998), 16α-hydroxy-20-oxopregn-5-en-3β-yl acetate, (I), was prepared from the corresponding 16α,17α-epoxide by selective reductive opening with aluminium amalgam under ultrasonic conditions (Moreno et al., 1993; Moreno, Sá e Melo & Campos Neves, 1998). A comparative structural study of the steroidal 16α-hydroxy and 16α,17α-epoxy ketones with those functionalized at C21 or C15 is relevant for the purpose of correlating the observed differences in chemical reactivity (Moreno et al., 1993) with the effects of the stereochemistry of the substituents on molecular conformation.

The X-ray diffraction study of the title compound indicates that all rings are fused trans. An ORTEPII (Johnson, 1976) drawing of the molecule with the corresponding atomic numbering scheme and ring labels is shown in Fig. 1. Bond lengths and angles are within the range of expected values (Allen et al., 1987), with averages Csp³—Csp³ 1.532 (4), Csp³—Csp² 1.504 (7) and Csp²—Csp² 1.321 (4) Å, except for a larger than ususal Csp²—Csp³ bond, i.e. C5—C10 [1.531 (4) Å].

Rings A and C have slightly flattened chair conformations, the mean values of their torsion angles being 53 (3) and 53.9 (15)°, respectively. As reported in a previous crystallographic work on the closely related 16α,17α-epoxy derivative (Andrade et al., 2001), the acetoxy group bonded to C3 does not disturb the usual chair conformation of the A ring of the steroid nucleus. The 3β-acetoxy group is planar and oriented equatorially. The dihedral angle between the acetoxy group and the mean molecular plane is 57.2 (2)°, showing that it is twisted around the C3—O3 bond. Due to the double C5═C6 bond, the environment of the C5 atom is planar [sum of the valence angles around C5 is 360.0 (5)°]. Consequently, ring B is highly distorted assuming an 8β,9α-half chair conformation distorted towards a 8β-sofa [asymmetry parameters (Duax & Norton, 1975) are ΔC₂(5,6) = 6.7 (4), ΔC_S(6) = 16.3 (3) and ΔC₂ = 47.8 (4)°]. The five-membered D ring assumes an unusual conformation close to 13β-envelope, with puckering parameters (Cremer & Pople, 1975) q₂ = 0.483 (3) Å, ϕ₂ = 188.2 (4)° [pseudo-rotation (Altona et al., 1968) and asymmetry parameters (Duax & Norton, 1975): Δ = 18.5 (6)°, ϕ_m = 48.7 (2)°, ΔC_s(13) = 9.3 (3) and ΔC₂(13,14) = 12.4 (4)°].

The conformation of the substituent group at C17 is characterized by a torsion angle C13—C17—C20—-O20 of 84.9 (3)°, slightly lower, but close to the values reported by Weeks et al. (1973) in a comparative study of six corticosteroids with a similar side chain at C17. The 17β-methyl ketone group is not coplanar with the mean molecular plane, the dihedral angle being 55.59 (14)°. The pseudo-torsion angle C19—C10—C13—C18 which measures the twist of the molecule is 3.4 (3)°, much smaller than the twist observed in the 16α,17α-epoxy steroid molecule [10.4 (2)°]. The linear dimension of the molecule given by the distance between terminal C21 and C23 atoms [13.680 (14) Å] is slightly smaller in the hydroxy- than in the epoxy-substituted steroid molecule [14.873 (4) Å].

The molecules are hydrogen bonded head-to-head via the hydroxy and methyl ketone groups. No weak C—H···O short contacts with suitable geometry to be classified as weak intermolecular interactions are found in the structure. Interestingly, the carbonyl O22 atom of the 3β-acetoxy group, which is a potential strong acceptor, is not involved in hydrogen bonding. This may be the reason of an increased librational motion or slight disorder of this atom, deduced from the enhanced displacement parameters of O22 when compared to those of neighbour atoms.

It should be stated that the absolute configuration of the molecule was not determined from the X-ray data but was chosen to give the correct chirality that was known beforehand from the synthesis route (Moreno et al., 1993).

Experimental top

16α,17α-Epoxy-20-oxopregn-5-en-3β-yl acetate, required for introduction of the 16α-hydroxy group, was easily prepared from commercially available 20-oxopregna-5,16-dien-3β-yl acetate through a two-step reaction (Kirk & Sá e Melo, 1979; Andrade et al., 2001). Synthesis of 16α-hydroxy-20-oxopregn-5-en-3β-yl acetate, (I), was efficiently accomplished by sonochemical reductive opening of the 16α,17α-epoxy ketone with aluminium amalgam (Moreno et al., 1993; Moreno, Sá e Melo & Campos Neves, 1998). The product of this reaction was isolated and identified as the title compound (I) from IR, ¹H and ¹³C NMR spectroscopy (Moreno et al., 1993). Crystals suitable for X-ray analysis were obtained by slow evaporation of a solution of the steroid in methanol.

Computing details top

Data collection: CAD-4 Software (Enraf-Nonius, 1989); cell refinement: CAD-4 Software; data reduction: HELENA (Spek, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXL97.

Figures top

	Fig. 1. ORTEPII (Johnson, 1976) plot of the title compound. Displacement ellipsoids are drawn at the 50% probability level except for H atoms which were given arbitrary radii.
	Fig. 2. Packing diagram showing the unit-cell contents viewed along the b axis and the hydrogen-bonding scheme.

16α-Hydroxy-20-oxopregn-5-en-3β-yl-acetate top

Crystal data top

C₂₃H₃₄O₄	F(000) = 408
M_r = 374.50	D_x = 1.192 Mg m⁻³
Monoclinic, P2₁	Mo Kα radiation, λ = 0.71073 Å
a = 12.110 (9) Å	Cell parameters from 25 reflections
b = 6.084 (3) Å	θ = 6.1–11.3°
c = 15.024 (11) Å	µ = 0.08 mm⁻¹
β = 109.54 (11)°	T = 293 K
V = 1043.1 (12) Å³	Plate, colourless
Z = 2	0.48 × 0.25 × 0.12 mm

Data collection top

Enraf-Nonius CAD-4 diffractometer	R_int = 0.040
Radiation source: fine-focus sealed tube	θ_max = 27.5°, θ_min = 3.4°
Graphite monochromator	h = −15→15
profile data from ω–2θ scans	k = 0→7
5099 measured reflections	l = −19→19
2553 independent reflections	3 standard reflections every 180 min
1631 reflections with I > 2σ(I)	intensity decay: 7.2%

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)] = 0.041	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.119	H-atom parameters constrained
S = 1.00	w = 1/[σ²(F_o²) + (0.0722P)²] where P = (F_o² + 2F_c²)/3
2553 reflections	(Δ/σ)_max < 0.001
254 parameters	Δρ_max = 0.16 e Å⁻³
1 restraint	Δρ_min = −0.19 e Å⁻³

Crystal data top

C₂₃H₃₄O₄	V = 1043.1 (12) Å³
M_r = 374.50	Z = 2
Monoclinic, P2₁	Mo Kα radiation
a = 12.110 (9) Å	µ = 0.08 mm⁻¹
b = 6.084 (3) Å	T = 293 K
c = 15.024 (11) Å	0.48 × 0.25 × 0.12 mm
β = 109.54 (11)°

Data collection top

Enraf-Nonius CAD-4 diffractometer	R_int = 0.040
5099 measured reflections	3 standard reflections every 180 min
2553 independent reflections	intensity decay: 7.2%
1631 reflections with I > 2σ(I)

Refinement top

R[F² > 2σ(F²)] = 0.041	1 restraint
wR(F²) = 0.119	H-atom parameters constrained
S = 1.00	Δρ_max = 0.16 e Å⁻³
2553 reflections	Δρ_min = −0.19 e Å⁻³
254 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

	x	y	z	U_iso*/U_eq
C9	0.72726 (18)	0.9296 (5)	0.52983 (16)	0.0370 (6)
H9	0.7127	1.0880	0.5216	0.044*
C8	0.86126 (19)	0.9042 (5)	0.57368 (17)	0.0387 (6)
H8	0.8817	0.7479	0.5768	0.046*
C14	0.90414 (19)	1.0010 (5)	0.67236 (17)	0.0382 (6)
H14	0.8843	1.1576	0.6643	0.046*
O3	0.52302 (16)	0.9422 (4)	0.12741 (13)	0.0620 (6)
C10	0.6767 (2)	0.8284 (5)	0.42967 (19)	0.0397 (6)
C7	0.9178 (2)	1.0229 (6)	0.51097 (18)	0.0456 (7)
H7A	0.9209	1.1788	0.5251	0.055*
H7B	0.9977	0.9711	0.5261	0.055*
C11	0.6640 (2)	0.8537 (5)	0.59778 (19)	0.0501 (7)
H11A	0.5815	0.8896	0.5705	0.060*
H11B	0.6706	0.6951	0.6043	0.060*
C6	0.8552 (2)	0.9913 (5)	0.40766 (19)	0.0476 (7)
H6	0.895 (2)	1.043 (6)	0.361 (2)	0.057*
O16	1.09727 (19)	1.2494 (5)	0.86089 (16)	0.0672 (7)
H16	1.095 (3)	1.274 (8)	0.914 (3)	0.081*
C19	0.6800 (3)	0.5757 (5)	0.4322 (2)	0.0578 (8)
H19A	0.6293	0.5227	0.4648	0.069*
H19B	0.7586	0.5272	0.4646	0.069*
H19C	0.6540	0.5197	0.3688	0.069*
C4	0.6937 (2)	0.8813 (6)	0.26356 (19)	0.0543 (8)
H4A	0.6897	0.7264	0.2475	0.065*
H4B	0.7421	0.9538	0.2324	0.065*
C13	0.8437 (2)	0.9133 (5)	0.74062 (19)	0.0403 (6)
C5	0.7490 (2)	0.9080 (5)	0.36968 (18)	0.0424 (6)
C2	0.4964 (2)	0.8724 (6)	0.27778 (19)	0.0545 (8)
H2A	0.4907	0.7160	0.2643	0.065*
H2B	0.4181	0.9341	0.2545	0.065*
C12	0.7124 (2)	0.9575 (6)	0.69538 (18)	0.0480 (7)
H12A	0.6713	0.8982	0.7355	0.058*
H12B	0.6989	1.1148	0.6902	0.058*
C1	0.5491 (2)	0.9090 (6)	0.38414 (18)	0.0478 (7)
H1A	0.5005	0.8343	0.4145	0.057*
H1B	0.5464	1.0649	0.3967	0.057*
C3	0.5714 (2)	0.9792 (6)	0.22882 (18)	0.0525 (7)
H3	0.5759	1.1375	0.2416	0.063*
C20	0.8878 (2)	0.9925 (6)	0.91855 (18)	0.0491 (7)
C15	1.0340 (2)	0.9922 (6)	0.73175 (18)	0.0515 (7)
H15A	1.0782	1.0991	0.7095	0.062*
H15B	1.0659	0.8471	0.7291	0.062*
O20	0.9438 (2)	0.8490 (5)	0.96974 (16)	0.0725 (7)
C17	0.9090 (2)	1.0545 (5)	0.82861 (18)	0.0423 (6)
H17	0.8821	1.2063	0.8140	0.051*
C18	0.8649 (3)	0.6684 (5)	0.7625 (2)	0.0572 (8)
H18A	0.8411	0.5864	0.7045	0.069*
H18B	0.8202	0.6211	0.8011	0.069*
H18C	0.9467	0.6438	0.7956	0.069*
C21	0.7945 (3)	1.1146 (6)	0.9411 (2)	0.0607 (9)
H21A	0.7854	1.0552	0.9974	0.073*
H21B	0.7220	1.1006	0.8896	0.073*
H21C	0.8156	1.2670	0.9507	0.073*
C16	1.0384 (2)	1.0466 (6)	0.83213 (19)	0.0499 (7)
H16A	1.0800	0.9297	0.8752	0.060*
C23	0.3880 (3)	1.0067 (10)	−0.0240 (2)	0.0874 (14)
H23A	0.3152	1.0808	−0.0548	0.105*
H23B	0.3760	0.8507	−0.0296	0.105*
H23C	0.4444	1.0488	−0.0531	0.105*
O22	0.3948 (3)	1.2105 (7)	0.1139 (2)	0.1163 (13)
C22	0.4323 (3)	1.0688 (9)	0.0778 (3)	0.0753 (12)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C9	0.0340 (11)	0.0331 (14)	0.0464 (14)	0.0012 (11)	0.0167 (10)	0.0049 (11)
C8	0.0342 (11)	0.0366 (14)	0.0451 (13)	0.0020 (12)	0.0130 (9)	−0.0037 (12)
C14	0.0378 (11)	0.0346 (14)	0.0448 (13)	0.0043 (12)	0.0174 (10)	0.0012 (12)
O3	0.0536 (11)	0.0819 (17)	0.0461 (11)	0.0083 (12)	0.0107 (8)	0.0084 (12)
C10	0.0360 (12)	0.0372 (15)	0.0457 (15)	−0.0001 (11)	0.0131 (11)	0.0009 (12)
C7	0.0384 (12)	0.0555 (19)	0.0476 (14)	−0.0065 (13)	0.0207 (10)	−0.0053 (14)
C11	0.0378 (12)	0.0608 (19)	0.0543 (16)	−0.0037 (14)	0.0188 (11)	0.0079 (15)
C6	0.0433 (13)	0.0574 (18)	0.0471 (14)	−0.0032 (14)	0.0219 (11)	−0.0026 (15)
O16	0.0647 (13)	0.0850 (17)	0.0560 (13)	−0.0251 (13)	0.0257 (11)	−0.0247 (13)
C19	0.0650 (18)	0.0436 (17)	0.060 (2)	−0.0060 (16)	0.0153 (15)	−0.0049 (15)
C4	0.0445 (14)	0.073 (2)	0.0461 (15)	0.0047 (15)	0.0154 (11)	−0.0016 (15)
C13	0.0416 (13)	0.0353 (14)	0.0462 (14)	0.0047 (12)	0.0177 (11)	0.0060 (12)
C5	0.0380 (12)	0.0463 (16)	0.0452 (14)	0.0044 (12)	0.0170 (10)	−0.0013 (13)
C2	0.0383 (12)	0.070 (2)	0.0516 (16)	0.0014 (14)	0.0097 (11)	0.0024 (15)
C12	0.0409 (12)	0.061 (2)	0.0485 (14)	0.0010 (14)	0.0232 (10)	0.0060 (15)
C1	0.0356 (12)	0.0598 (18)	0.0493 (15)	0.0009 (14)	0.0159 (10)	0.0009 (15)
C3	0.0498 (14)	0.060 (2)	0.0459 (15)	0.0027 (15)	0.0140 (11)	0.0012 (15)
C20	0.0519 (14)	0.0553 (18)	0.0398 (14)	0.0009 (15)	0.0150 (11)	0.0005 (15)
C15	0.0400 (12)	0.068 (2)	0.0484 (15)	0.0018 (15)	0.0174 (10)	−0.0080 (16)
O20	0.0840 (16)	0.0777 (18)	0.0618 (14)	0.0249 (15)	0.0324 (11)	0.0271 (14)
C17	0.0457 (13)	0.0385 (15)	0.0446 (14)	0.0067 (13)	0.0176 (11)	0.0041 (12)
C18	0.0724 (19)	0.0370 (16)	0.0589 (17)	0.0031 (15)	0.0177 (14)	0.0073 (14)
C21	0.0593 (17)	0.075 (2)	0.0552 (17)	0.0035 (17)	0.0285 (14)	−0.0040 (17)
C16	0.0441 (13)	0.0605 (19)	0.0449 (15)	0.0038 (14)	0.0146 (11)	−0.0034 (14)
C23	0.0653 (19)	0.125 (4)	0.062 (2)	0.003 (3)	0.0077 (15)	0.029 (3)
O22	0.120 (2)	0.135 (3)	0.091 (2)	0.073 (3)	0.0321 (17)	0.028 (2)
C22	0.0548 (19)	0.103 (3)	0.066 (2)	0.017 (2)	0.0172 (16)	0.026 (2)

Geometric parameters (Å, º) top

C9—C11	1.538 (4)	C13—C12	1.529 (4)
C9—C8	1.541 (3)	C13—C18	1.529 (5)
C9—C10	1.550 (4)	C13—C17	1.553 (4)
C9—H9	0.9800	C2—C3	1.495 (4)
C8—C14	1.516 (4)	C2—C1	1.526 (4)
C8—C7	1.520 (4)	C2—H2A	0.9700
C8—H8	0.9800	C2—H2B	0.9700
C14—C15	1.527 (4)	C12—H12A	0.9700
C14—C13	1.541 (4)	C12—H12B	0.9700
C14—H14	0.9800	C1—H1A	0.9700
O3—C22	1.344 (4)	C1—H1B	0.9700
O3—C3	1.455 (4)	C3—H3	0.9800
C10—C5	1.531 (4)	C20—O20	1.210 (4)
C10—C19	1.538 (4)	C20—C21	1.484 (4)
C10—C1	1.545 (4)	C20—C17	1.505 (4)
C7—C6	1.495 (4)	C15—C16	1.527 (4)
C7—H7A	0.9700	C15—H15A	0.9700
C7—H7B	0.9700	C15—H15B	0.9700
C11—C12	1.522 (4)	C17—C16	1.551 (4)
C11—H11A	0.9700	C17—H17	0.9800
C11—H11B	0.9700	C18—H18A	0.9600
C6—C5	1.321 (4)	C18—H18B	0.9600
C6—H6	1.02 (3)	C18—H18C	0.9600
O16—C16	1.418 (4)	C21—H21A	0.9600
O16—H16	0.82 (4)	C21—H21B	0.9600
C19—H19A	0.9600	C21—H21C	0.9600
C19—H19B	0.9600	C16—H16A	0.9800
C19—H19C	0.9600	C23—C22	1.490 (5)
C4—C5	1.517 (4)	C23—H23A	0.9600
C4—C3	1.518 (4)	C23—H23B	0.9600
C4—H4A	0.9700	C23—H23C	0.9600
C4—H4B	0.9700	O22—C22	1.187 (5)

C11—C9—C8	111.9 (2)	C1—C2—H2A	109.7
C11—C9—C10	113.7 (2)	C3—C2—H2B	109.7
C8—C9—C10	113.1 (2)	C1—C2—H2B	109.7
C11—C9—H9	105.8	H2A—C2—H2B	108.2
C8—C9—H9	105.8	C11—C12—C13	111.3 (2)
C10—C9—H9	105.8	C11—C12—H12A	109.4
C14—C8—C7	110.1 (2)	C13—C12—H12A	109.4
C14—C8—C9	110.3 (2)	C11—C12—H12B	109.4
C7—C8—C9	108.4 (2)	C13—C12—H12B	109.4
C14—C8—H8	109.3	H12A—C12—H12B	108.0
C7—C8—H8	109.3	C2—C1—C10	115.0 (2)
C9—C8—H8	109.3	C2—C1—H1A	108.5
C8—C14—C15	120.4 (2)	C10—C1—H1A	108.5
C8—C14—C13	115.6 (2)	C2—C1—H1B	108.5
C15—C14—C13	103.0 (2)	C10—C1—H1B	108.5
C8—C14—H14	105.5	H1A—C1—H1B	107.5
C15—C14—H14	105.5	O3—C3—C2	110.5 (2)
C13—C14—H14	105.5	O3—C3—C4	107.7 (2)
C22—O3—C3	117.4 (3)	C2—C3—C4	110.1 (3)
C5—C10—C19	108.4 (3)	O3—C3—H3	109.5
C5—C10—C1	108.9 (2)	C2—C3—H3	109.5
C19—C10—C1	110.0 (3)	C4—C3—H3	109.5
C5—C10—C9	109.1 (2)	O20—C20—C21	121.6 (3)
C19—C10—C9	112.0 (3)	O20—C20—C17	121.6 (3)
C1—C10—C9	108.4 (2)	C21—C20—C17	116.8 (3)
C6—C7—C8	113.9 (2)	C14—C15—C16	105.0 (2)
C6—C7—H7A	108.8	C14—C15—H15A	110.7
C8—C7—H7A	108.8	C16—C15—H15A	110.7
C6—C7—H7B	108.8	C14—C15—H15B	110.7
C8—C7—H7B	108.8	C16—C15—H15B	110.7
H7A—C7—H7B	107.7	H15A—C15—H15B	108.8
C12—C11—C9	113.4 (2)	C20—C17—C16	115.8 (2)
C12—C11—H11A	108.9	C20—C17—C13	115.7 (2)
C9—C11—H11A	108.9	C16—C17—C13	103.5 (2)
C12—C11—H11B	108.9	C20—C17—H17	107.1
C9—C11—H11B	108.9	C16—C17—H17	107.1
H11A—C11—H11B	107.7	C13—C17—H17	107.1
C5—C6—C7	125.5 (3)	C13—C18—H18A	109.5
C5—C6—H6	116.0 (15)	C13—C18—H18B	109.5
C7—C6—H6	118.5 (15)	H18A—C18—H18B	109.5
C16—O16—H16	106 (3)	C13—C18—H18C	109.5
C10—C19—H19A	109.5	H18A—C18—H18C	109.5
C10—C19—H19B	109.5	H18B—C18—H18C	109.5
H19A—C19—H19B	109.5	C20—C21—H21A	109.5
C10—C19—H19C	109.5	C20—C21—H21B	109.5
H19A—C19—H19C	109.5	H21A—C21—H21B	109.5
H19B—C19—H19C	109.5	C20—C21—H21C	109.5
C5—C4—C3	110.9 (2)	H21A—C21—H21C	109.5
C5—C4—H4A	109.5	H21B—C21—H21C	109.5
C3—C4—H4A	109.5	O16—C16—C15	109.7 (3)
C5—C4—H4B	109.5	O16—C16—C17	112.5 (3)
C3—C4—H4B	109.5	C15—C16—C17	105.8 (2)
H4A—C4—H4B	108.1	O16—C16—H16A	109.6
C12—C13—C18	110.0 (3)	C15—C16—H16A	109.6
C12—C13—C14	107.3 (2)	C17—C16—H16A	109.6
C18—C13—C14	113.4 (2)	C22—C23—H23A	109.5
C12—C13—C17	116.0 (2)	C22—C23—H23B	109.5
C18—C13—C17	110.8 (2)	H23A—C23—H23B	109.5
C14—C13—C17	98.9 (2)	C22—C23—H23C	109.5
C6—C5—C4	121.3 (3)	H23A—C23—H23C	109.5
C6—C5—C10	122.2 (2)	H23B—C23—H23C	109.5
C4—C5—C10	116.5 (2)	O22—C22—O3	122.0 (4)
C3—C2—C1	110.0 (2)	O22—C22—C23	126.2 (4)
C3—C2—H2A	109.7	O3—C22—C23	111.8 (4)

C11—C9—C8—C14	−48.4 (3)	C9—C11—C12—C13	−56.6 (3)
C10—C9—C8—C14	−178.4 (2)	C18—C13—C12—C11	−67.2 (3)
C11—C9—C8—C7	−169.0 (2)	C14—C13—C12—C11	56.6 (3)
C10—C9—C8—C7	61.0 (3)	C17—C13—C12—C11	166.0 (2)
C7—C8—C14—C15	−61.6 (3)	C3—C2—C1—C10	−56.4 (4)
C9—C8—C14—C15	178.8 (2)	C5—C10—C1—C2	46.8 (4)
C7—C8—C14—C13	173.6 (2)	C19—C10—C1—C2	−71.8 (4)
C9—C8—C14—C13	54.0 (3)	C9—C10—C1—C2	165.5 (3)
C11—C9—C10—C5	−177.8 (2)	C22—O3—C3—C2	79.1 (4)
C8—C9—C10—C5	−48.7 (3)	C22—O3—C3—C4	−160.6 (3)
C11—C9—C10—C19	−57.7 (3)	C1—C2—C3—O3	179.0 (3)
C8—C9—C10—C19	71.4 (3)	C1—C2—C3—C4	60.2 (4)
C11—C9—C10—C1	63.8 (3)	C5—C4—C3—O3	−178.5 (3)
C8—C9—C10—C1	−167.1 (2)	C5—C4—C3—C2	−57.9 (4)
C14—C8—C7—C6	−161.7 (2)	C8—C14—C15—C16	−165.4 (3)
C9—C8—C7—C6	−41.0 (3)	C13—C14—C15—C16	−34.8 (3)
C8—C9—C11—C12	51.5 (3)	O20—C20—C17—C16	−36.5 (4)
C10—C9—C11—C12	−178.8 (2)	C21—C20—C17—C16	144.0 (3)
C8—C7—C6—C5	13.0 (4)	O20—C20—C17—C13	84.9 (3)
C8—C14—C13—C12	−57.6 (3)	C21—C20—C17—C13	−94.6 (3)
C15—C14—C13—C12	168.9 (2)	C12—C13—C17—C20	74.9 (3)
C8—C14—C13—C18	64.0 (3)	C18—C13—C17—C20	−51.5 (3)
C15—C14—C13—C18	−69.4 (3)	C14—C13—C17—C20	−170.8 (2)
C8—C14—C13—C17	−178.6 (2)	C12—C13—C17—C16	−157.4 (2)
C15—C14—C13—C17	48.0 (3)	C18—C13—C17—C16	76.3 (3)
C7—C6—C5—C4	−179.5 (3)	C14—C13—C17—C16	−43.0 (3)
C7—C6—C5—C10	−1.0 (5)	C14—C15—C16—O16	−114.3 (3)
C3—C4—C5—C6	−129.7 (3)	C14—C15—C16—C17	7.2 (3)
C3—C4—C5—C10	51.7 (4)	C20—C17—C16—O16	−89.8 (3)
C19—C10—C5—C6	−103.8 (3)	C13—C17—C16—O16	142.5 (2)
C1—C10—C5—C6	136.6 (3)	C20—C17—C16—C15	150.4 (3)
C9—C10—C5—C6	18.4 (4)	C13—C17—C16—C15	22.7 (3)
C19—C10—C5—C4	74.8 (3)	C3—O3—C22—O22	2.4 (5)
C1—C10—C5—C4	−44.8 (3)	C3—O3—C22—C23	−177.4 (3)
C9—C10—C5—C4	−163.0 (2)	C19—C10—C13—C18	3.4 (3)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O16—H16···O20ⁱ	0.82 (4)	2.01 (4)	2.817 (4)	169 (3)

Symmetry code: (i) −x+2, y+1/2, −z+2.

Experimental details

Crystal data
Chemical formula	C₂₃H₃₄O₄
M_r	374.50
Crystal system, space group	Monoclinic, P2₁
Temperature (K)	293
a, b, c (Å)	12.110 (9), 6.084 (3), 15.024 (11)
β (°)	109.54 (11)
V (Å³)	1043.1 (12)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.08
Crystal size (mm)	0.48 × 0.25 × 0.12

Data collection
Diffractometer	Enraf-Nonius CAD-4 diffractometer
Absorption correction	–
No. of measured, independent and observed [I > 2σ(I)] reflections	5099, 2553, 1631
R_int	0.040
(sin θ/λ)_max (Å⁻¹)	0.649

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.041, 0.119, 1.00
No. of reflections	2553
No. of parameters	254
No. of restraints	1
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.16, −0.19

Computer programs: CAD-4 Software (Enraf-Nonius, 1989), CAD-4 Software, HELENA (Spek, 1997), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEPII (Johnson, 1976), SHELXL97.

Selected geometric parameters (Å, º) top

C10—C5	1.531 (4)	C4—C5	1.517 (4)
C6—C5	1.321 (4)	O22—C22	1.187 (5)

O20—C20—C17—C13	84.9 (3)	C3—O3—C22—O22	2.4 (5)