ent-Kaur-16-en-19-al

The title ent-kaurane diterpene compound, C₂₀H₃₀O, was isolated from the roots of Bruguiera cylindrica (Rhizophoraceae), a mangrove plant. The mol­ecule contains a fused four-ring system, with the three cyclo­hexane rings in standard chair conformations and the cyclo­pentane ring adopting an envelope conformation. The aldehyde is bis­ectionally attached to the cyclo­hexane ring. The methyl­ene group is coplanar with the attached cyclo­pentane ring. In the crystal structure, mol­ecules are packed by van der Waals inter­actions.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.035
• wR factor = 0.097
• Data-to-parameter ratio = 14.1

checkCIF/PLATON results

No syntax errors found



Alert level G
REFLT03_ALERT_4_G 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.
           From the CIF: _diffrn_reflns_theta_max           30.00
           From the CIF: _reflns_number_total               2709
           Count of symmetry unique reflns         2710
           Completeness (_total/calc)             99.96%
           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
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C4     = .          R
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C5     = .          S
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C8     = .          S
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C9     = .          R
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C10    = .          S
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C13    = .          R

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   0 ALERT level C = Check and explain
   7 ALERT level G = General alerts; check

   6 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

The title ent-kaurane compound, known as ent-kaur-16-ene-19-al, was isolated from the roots of Bruguiera cylindrica (Rhizophoraceae), a mangrove plant which was found in South East Asia. In our continuing research on bioactive compounds from mangrove sources, we have studied the chemical constituents from the roots of Bruguiera cylindrica (Rhizophoraceae) to search for the bioactive components. We have previously reported the crystal structure of the ent-kaur-16-ene-13,19-diol which was isolated from this plant (Salae et al., 2007). We herein report the crystal structure of the title compound which has an inhibitory activity on vascular smooth muscle contraction (Müller et al., 2003).

The molecule of the title compound contains a fused four-ring system A/B/C/D (Scheme 1). The A/B ring junction is trans-fused, B/C and C/D are cis-fused (Fig. 1). The three cyclohexane rings has the standard chair conformations; the cyclopentane ring adopts an envelope conformation with atom C14 displaced from the C8/C15/C16/C13 plane by -0.2891 (14) Å, and with puckering parameters (Cremer & Pople, 1975) Q = 0.459 (1) Å and φ = 30.35 (18)°. The methylene group is planarly attached to cyclopentane ring at atom C16. The bond angles around C16 are indicative of sp² hybridization for these atoms, with the geometric parameters being given in the supplementary materials. The orientation of the aldehyde group can be indicated by the torsion angles C3–C4–C19–O1 = -16.3 (2)° and C5–C4–C19–O1 = -140.60((15)°. All bond lengths and angles are within normal ranges (Allen et al., 1987) and comparable to the closely related structure ent-Kaur-16-ene-13,19-diol (Salae et al., 2007). The title structure is isomorphous to ent-Kaur-15-ene-19-al (Karle, 1972) and these two structures crystallized out in the same space group and have almost identical unit-cell dimensions. The differences in these two structures are that in the structure of ent-Kaur-15-ene-19-al, the functional group attached to C16 is a methyl group and C15—C16 is a C═C bond. The origins of the structures are different; ent-Kaur-15-ene-19-al was isolated from the tubers of Espeelita weddeli, a Composita which grows at 10,0000 feet in the Venezuelan Andes.

In the crystal packing of the title compound, the molecules are packed by Van de Waals interactions (Fig. 2).

Related literature

For the values of bond lengths and angles, see Allen et al. (1987). For literature on ring conformations, see Cremer & Pople (1975). For further details of ent-kaurane diterpenes and their bioactive properties, see, for example: Karle (1972); Müller et al. (2003); Salae et al. (2007).

S2. Experimental

The air-dried roots of Bruguiera cylindrica (6.0 kg) were chopped and extracted with CH₂Cl₂ (2 x 22 l) for one week at room temperature. Removal of the solvent from CH₂Cl₂ extract under reduced pressure gave a yellow viscous residue (38.5 g) which was subjected to quick column chromatography over siliga gel using solvents of increasing polarity from n-hexane through EtOAc to afford 14 fractions (F1—F14). Fraction F6 was further separated by quick column chromatography using CH₂Cl₂-acetone (9:1) to give title compound (11.8 mg). Colorless plate-shaped single crystals of the title compound were recrystallized from n-hexane after several days [Mp. 387–388 K].

S3. Refinement

All H atoms were positioned geometrically and allowed to ride on their parent atoms, with the C—H distances in the range 0.93–0.98 Å. The U_iso values were constrained to be 1.5U_eq of the carrier atom for methyl H atoms and 1.2U_eq for the remaining H atoms. A rotating group model was used for the methyl groups. A total of 2009 Friedel pairs were merged before final refinement as there is no large anomalous dispersion for the determination of the absolute configuration.

Computing details

Data collection: APEX2 (Bruker, 2005); cell refinement: APEX2 (Bruker, 2005); data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXTL (Sheldrick, 1998); program(s) used to refine structure: SHELXTL (Sheldrick, 1998); molecular graphics: SHELXTL (Sheldrick, 1998); software used to prepare material for publication: SHELXTL (Sheldrick, 1998) and PLATON (Spek, 2003).

Figures

	Fig. 1. The asymmetric unit of the title compound, showing 40% probability displacement ellipsoids and the atomic numbering scheme.
	Fig. 2. The crystal packing of the title compound view along the b axis.

ent-Kaur-16-en-19-al

Crystal data

C20H30O	Dx = 1.171 Mg m^−3
Mr = 286.44	Melting point = 387–388 K
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 2709 reflections
a = 6.3126 (2) Å	θ = 1.8–30.0°
b = 11.2823 (4) Å	µ = 0.07 mm^−1
c = 22.8044 (7) Å	T = 100 K
V = 1624.14 (9) Å^3	Plate, colorless
Z = 4	0.56 × 0.40 × 0.13 mm
F(000) = 632

Data collection

Bruker SMART APEXII CCD area-detector diffractometer	2709 independent reflections
Radiation source: fine-focus sealed tube	2571 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.029
Detector resolution: 8.33 pixels mm^-1	θmax = 30.0°, θmin = 1.8°
ω scans	h = −8→8
Absorption correction: multi-scan (SADABS; Bruker, 2005)	k = −14→15
Tmin = 0.952, Tmax = 0.991	l = −27→32
20475 measured reflections

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)] = 0.035	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.097	H-atom parameters constrained
S = 1.07	w = 1/[σ^2(Fo^2) + (0.0597P)^2 + 0.215P] where P = (Fo^2 + 2Fc^2)/3
2709 reflections	(Δ/σ)max = 0.001
192 parameters	Δρmax = 0.31 e Å^−3
0 restraints	Δρmin = −0.17 e Å^−3

Special details

Experimental. The low-temparture data was collected with the Oxford Cyrosystem Cobra low-temperature attachment.

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
O1	0.34848 (17)	0.85293 (11)	0.74695 (5)	0.0330 (3)
C1	0.8278 (2)	0.73642 (11)	0.86634 (6)	0.0228 (3)
H1A	0.9792	0.7263	0.8610	0.027*
H1B	0.7863	0.6914	0.9007	0.027*
C2	0.7129 (3)	0.68629 (12)	0.81270 (7)	0.0284 (3)
H2A	0.7555	0.6045	0.8068	0.034*
H2B	0.5614	0.6874	0.8197	0.034*
C3	0.7620 (2)	0.75744 (14)	0.75763 (6)	0.0274 (3)
H3A	0.6761	0.7275	0.7256	0.033*
H3B	0.9095	0.7455	0.7472	0.033*
C4	0.7209 (2)	0.89086 (13)	0.76445 (6)	0.0204 (3)
C5	0.8351 (2)	0.93785 (11)	0.82017 (5)	0.0169 (2)
H5A	0.9856	0.9216	0.8133	0.020*
C6	0.8231 (2)	1.07270 (12)	0.82971 (6)	0.0215 (3)
H6A	0.8473	1.1135	0.7929	0.026*
H6B	0.6834	1.0942	0.8439	0.026*
C7	0.9906 (2)	1.10943 (12)	0.87436 (6)	0.0226 (3)
H7A	0.9862	1.1948	0.8793	0.027*
H7B	1.1296	1.0886	0.8595	0.027*
C8	0.9579 (2)	1.05008 (11)	0.93396 (5)	0.0163 (2)
C9	0.93310 (19)	0.91333 (11)	0.92681 (5)	0.0150 (2)
H9A	1.0735	0.8860	0.9145	0.018*
C10	0.78062 (19)	0.86948 (11)	0.87740 (5)	0.0153 (2)
C11	0.8994 (2)	0.85560 (11)	0.98797 (6)	0.0190 (2)
H11A	0.8348	0.7785	0.9821	0.023*
H11B	1.0374	0.8425	1.0055	0.023*
C12	0.7633 (2)	0.92480 (12)	1.03200 (6)	0.0218 (3)
H12A	0.7859	0.8932	1.0711	0.026*
H12B	0.6148	0.9147	1.0223	0.026*
C13	0.8187 (2)	1.05776 (12)	1.03149 (6)	0.0198 (3)
H13A	0.7411	1.1021	1.0616	0.024*
C14	0.7751 (2)	1.10491 (11)	0.96959 (6)	0.0199 (3)
H14A	0.7801	1.1908	0.9685	0.024*
H14B	0.6385	1.0784	0.9552	0.024*
C15	1.1454 (2)	1.07505 (12)	0.97590 (6)	0.0218 (3)
H15A	1.2538	1.0148	0.9715	0.026*
H15B	1.2076	1.1518	0.9674	0.026*
C16	1.0568 (2)	1.07321 (12)	1.03703 (6)	0.0204 (3)
C17	1.1674 (3)	1.08212 (14)	1.08712 (6)	0.0282 (3)
H17A	1.3140	1.0904	1.0859	0.034*
H17B	1.0975	1.0800	1.1230	0.034*
C18	0.8071 (3)	0.95405 (17)	0.70911 (6)	0.0318 (4)
H18A	0.7532	0.9155	0.6747	0.048*
H18B	0.9590	0.9505	0.7090	0.048*
H18C	0.7624	1.0354	0.7093	0.048*
C19	0.4858 (2)	0.91868 (14)	0.76388 (6)	0.0230 (3)
H19A	0.4442	0.9926	0.7777	0.028*
C20	0.5454 (2)	0.88135 (11)	0.89396 (6)	0.0178 (2)
H20A	0.4606	0.8382	0.8663	0.027*
H20B	0.5056	0.9635	0.8933	0.027*
H20C	0.5233	0.8498	0.9326	0.027*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0191 (5)	0.0504 (7)	0.0296 (6)	0.0000 (5)	−0.0040 (4)	−0.0031 (5)
C1	0.0265 (7)	0.0165 (5)	0.0254 (6)	0.0048 (5)	−0.0092 (5)	−0.0052 (5)
C2	0.0320 (8)	0.0205 (6)	0.0325 (7)	0.0043 (6)	−0.0107 (6)	−0.0108 (5)
C3	0.0225 (6)	0.0354 (8)	0.0243 (7)	0.0058 (6)	−0.0040 (6)	−0.0143 (6)
C4	0.0164 (5)	0.0303 (7)	0.0144 (5)	0.0014 (5)	−0.0002 (4)	−0.0027 (5)
C5	0.0153 (5)	0.0217 (5)	0.0136 (5)	0.0006 (5)	0.0016 (4)	−0.0018 (4)
C6	0.0270 (6)	0.0209 (6)	0.0166 (6)	−0.0025 (5)	0.0017 (5)	0.0045 (5)
C7	0.0300 (7)	0.0211 (6)	0.0168 (6)	−0.0074 (5)	0.0040 (5)	0.0018 (5)
C8	0.0192 (5)	0.0154 (5)	0.0141 (5)	−0.0026 (5)	0.0027 (4)	−0.0004 (4)
C9	0.0152 (5)	0.0151 (5)	0.0149 (5)	0.0006 (4)	−0.0003 (4)	−0.0006 (4)
C10	0.0150 (5)	0.0149 (5)	0.0160 (5)	0.0011 (4)	−0.0006 (4)	−0.0005 (4)
C11	0.0221 (6)	0.0162 (5)	0.0187 (5)	−0.0013 (5)	−0.0050 (5)	0.0031 (5)
C12	0.0226 (6)	0.0264 (6)	0.0163 (5)	−0.0060 (5)	0.0011 (5)	0.0045 (5)
C13	0.0219 (6)	0.0228 (6)	0.0148 (5)	−0.0006 (5)	0.0042 (5)	−0.0029 (5)
C14	0.0258 (6)	0.0165 (5)	0.0173 (5)	0.0038 (5)	0.0032 (5)	−0.0020 (4)
C15	0.0229 (6)	0.0221 (6)	0.0204 (6)	−0.0075 (5)	0.0025 (5)	−0.0045 (5)
C16	0.0238 (6)	0.0181 (6)	0.0192 (6)	−0.0043 (5)	0.0035 (5)	−0.0026 (5)
C17	0.0294 (7)	0.0338 (7)	0.0215 (6)	−0.0074 (6)	0.0001 (6)	−0.0002 (6)
C18	0.0256 (7)	0.0556 (10)	0.0144 (6)	−0.0045 (7)	0.0025 (5)	−0.0005 (6)
C19	0.0196 (6)	0.0338 (7)	0.0156 (6)	0.0051 (6)	−0.0003 (5)	0.0016 (5)
C20	0.0154 (5)	0.0207 (6)	0.0173 (6)	−0.0014 (5)	0.0008 (4)	0.0020 (5)

Geometric parameters (Å, º)

O1—C19	1.2043 (19)	C9—C10	1.5625 (17)
C1—C2	1.5304 (19)	C9—H9A	0.9800
C1—C10	1.5511 (17)	C10—C20	1.5378 (17)
C1—H1A	0.9700	C11—C12	1.5350 (19)
C1—H1B	0.9700	C11—H11A	0.9700
C2—C3	1.522 (2)	C11—H11B	0.9700
C2—H2A	0.9700	C12—C13	1.5403 (18)
C2—H2B	0.9700	C12—H12A	0.9700
C3—C4	1.535 (2)	C12—H12B	0.9700
C3—H3A	0.9700	C13—C16	1.519 (2)
C3—H3B	0.9700	C13—C14	1.5333 (18)
C4—C19	1.5169 (19)	C13—H13A	0.9800
C4—C18	1.548 (2)	C14—H14A	0.9700
C4—C5	1.5543 (17)	C14—H14B	0.9700
C5—C6	1.5388 (18)	C15—C16	1.5020 (18)
C5—C10	1.5545 (17)	C15—H15A	0.9700
C5—H5A	0.9800	C15—H15B	0.9700
C6—C7	1.525 (2)	C16—C17	1.343 (2)
C6—H6A	0.9700	C17—H17A	0.9300
C6—H6B	0.9700	C17—H17B	0.9300
C7—C8	1.5291 (17)	C18—H18A	0.9600
C7—H7A	0.9700	C18—H18B	0.9600
C7—H7B	0.9700	C18—H18C	0.9600
C8—C14	1.5409 (18)	C19—H19A	0.9300
C8—C15	1.5475 (19)	C20—H20A	0.9600
C8—C9	1.5593 (16)	C20—H20B	0.9600
C9—C11	1.5538 (17)	C20—H20C	0.9600
C2—C1—C10	113.36 (11)	C1—C10—C5	107.53 (10)
C2—C1—H1A	108.9	C20—C10—C9	112.95 (10)
C10—C1—H1A	108.9	C1—C10—C9	107.78 (10)
C2—C1—H1B	108.9	C5—C10—C9	108.19 (10)
C10—C1—H1B	108.9	C12—C11—C9	116.78 (10)
H1A—C1—H1B	107.7	C12—C11—H11A	108.1
C3—C2—C1	111.59 (12)	C9—C11—H11A	108.1
C3—C2—H2A	109.3	C12—C11—H11B	108.1
C1—C2—H2A	109.3	C9—C11—H11B	108.1
C3—C2—H2B	109.3	H11A—C11—H11B	107.3
C1—C2—H2B	109.3	C11—C12—C13	111.30 (11)
H2A—C2—H2B	108.0	C11—C12—H12A	109.4
C2—C3—C4	113.52 (11)	C13—C12—H12A	109.4
C2—C3—H3A	108.9	C11—C12—H12B	109.4
C4—C3—H3A	108.9	C13—C12—H12B	109.4
C2—C3—H3B	108.9	H12A—C12—H12B	108.0
C4—C3—H3B	108.9	C16—C13—C14	102.38 (11)
H3A—C3—H3B	107.7	C16—C13—C12	109.62 (12)
C19—C4—C3	111.56 (12)	C14—C13—C12	107.71 (11)
C19—C4—C18	103.98 (12)	C16—C13—H13A	112.2
C3—C4—C18	108.03 (12)	C14—C13—H13A	112.2
C19—C4—C5	112.98 (11)	C12—C13—H13A	112.2
C3—C4—C5	109.80 (11)	C13—C14—C8	102.23 (10)
C18—C4—C5	110.25 (11)	C13—C14—H14A	111.3
C6—C5—C4	115.46 (11)	C8—C14—H14A	111.3
C6—C5—C10	111.16 (10)	C13—C14—H14B	111.3
C4—C5—C10	114.48 (11)	C8—C14—H14B	111.3
C6—C5—H5A	104.8	H14A—C14—H14B	109.2
C4—C5—H5A	104.8	C16—C15—C8	106.65 (11)
C10—C5—H5A	104.8	C16—C15—H15A	110.4
C7—C6—C5	109.20 (11)	C8—C15—H15A	110.4
C7—C6—H6A	109.8	C16—C15—H15B	110.4
C5—C6—H6A	109.8	C8—C15—H15B	110.4
C7—C6—H6B	109.8	H15A—C15—H15B	108.6
C5—C6—H6B	109.8	C17—C16—C15	126.52 (13)
H6A—C6—H6B	108.3	C17—C16—C13	126.46 (13)
C6—C7—C8	112.39 (11)	C15—C16—C13	107.02 (12)
C6—C7—H7A	109.1	C16—C17—H17A	120.0
C8—C7—H7A	109.1	C16—C17—H17B	120.0
C6—C7—H7B	109.1	H17A—C17—H17B	120.0
C8—C7—H7B	109.1	C4—C18—H18A	109.5
H7A—C7—H7B	107.9	C4—C18—H18B	109.5
C7—C8—C14	113.20 (11)	H18A—C18—H18B	109.5
C7—C8—C15	111.50 (11)	C4—C18—H18C	109.5
C14—C8—C15	100.00 (10)	H18A—C18—H18C	109.5
C7—C8—C9	110.73 (10)	H18B—C18—H18C	109.5
C14—C8—C9	112.16 (10)	O1—C19—C4	125.40 (14)
C15—C8—C9	108.75 (10)	O1—C19—H19A	117.3
C11—C9—C8	109.56 (10)	C4—C19—H19A	117.3
C11—C9—C10	115.49 (10)	C10—C20—H20A	109.5
C8—C9—C10	116.78 (10)	C10—C20—H20B	109.5
C11—C9—H9A	104.5	H20A—C20—H20B	109.5
C8—C9—H9A	104.5	C10—C20—H20C	109.5
C10—C9—H9A	104.5	H20A—C20—H20C	109.5
C20—C10—C1	108.04 (11)	H20B—C20—H20C	109.5
C20—C10—C5	112.13 (10)
C10—C1—C2—C3	55.54 (17)	C6—C5—C10—C9	−55.86 (13)
C1—C2—C3—C4	−53.27 (17)	C4—C5—C10—C9	171.08 (10)
C2—C3—C4—C19	−74.39 (16)	C11—C9—C10—C20	54.39 (14)
C2—C3—C4—C18	171.92 (12)	C8—C9—C10—C20	−76.59 (14)
C2—C3—C4—C5	51.65 (16)	C11—C9—C10—C1	−64.88 (13)
C19—C4—C5—C6	−59.68 (16)	C8—C9—C10—C1	164.13 (11)
C3—C4—C5—C6	175.09 (11)	C11—C9—C10—C5	179.12 (10)
C18—C4—C5—C6	56.18 (15)	C8—C9—C10—C5	48.13 (13)
C19—C4—C5—C10	71.32 (15)	C8—C9—C11—C12	37.63 (15)
C3—C4—C5—C10	−53.91 (14)	C10—C9—C11—C12	−96.71 (13)
C18—C4—C5—C10	−172.82 (12)	C9—C11—C12—C13	−42.84 (16)
C4—C5—C6—C7	−163.78 (11)	C11—C12—C13—C16	−50.07 (15)
C10—C5—C6—C7	63.65 (14)	C11—C12—C13—C14	60.58 (14)
C5—C6—C7—C8	−60.81 (15)	C16—C13—C14—C8	43.12 (12)
C6—C7—C8—C14	−75.83 (14)	C12—C13—C14—C8	−72.41 (13)
C6—C7—C8—C15	172.33 (11)	C7—C8—C14—C13	−163.78 (11)
C6—C7—C8—C9	51.10 (15)	C15—C8—C14—C13	−45.06 (12)
C7—C8—C9—C11	−179.80 (11)	C9—C8—C14—C13	70.04 (13)
C14—C8—C9—C11	−52.29 (14)	C7—C8—C15—C16	150.54 (11)
C15—C8—C9—C11	57.36 (13)	C14—C8—C15—C16	30.58 (13)
C7—C8—C9—C10	−46.11 (15)	C9—C8—C15—C16	−87.08 (12)
C14—C8—C9—C10	81.39 (13)	C8—C15—C16—C17	174.74 (14)
C15—C8—C9—C10	−168.96 (10)	C8—C15—C16—C13	−4.54 (14)
C2—C1—C10—C20	66.22 (15)	C14—C13—C16—C17	157.01 (14)
C2—C1—C10—C5	−55.00 (15)	C12—C13—C16—C17	−88.85 (17)
C2—C1—C10—C9	−171.42 (12)	C14—C13—C16—C15	−23.71 (14)
C6—C5—C10—C20	69.36 (14)	C12—C13—C16—C15	90.43 (13)
C4—C5—C10—C20	−63.70 (14)	C3—C4—C19—O1	−16.3 (2)
C6—C5—C10—C1	−172.01 (11)	C18—C4—C19—O1	99.86 (17)
C4—C5—C10—C1	54.93 (14)	C5—C4—C19—O1	−140.60 (15)