Di­methyl 6-methoxy-4a[beta]-methyl-9-oxo-1,2,3,4,4a,9,10,10a[beta]-octa­hydro­phenanthrene-1,1-di­carboxyl­ate

In the title tricyclic keto-diester, C₂₀H₂₄O₆, a potential intermediate in the synthesis of bioactive podocarpic acid, the outer cyclo­hexane ring (in a chair conformation) is cis fused to the central cyclo­hexanone ring (in a half-chair conformation). The conformational analysis of the compound, investigated by semi-empirical quantum mechanical AM1 calculations, shows a good agreement with the X-ray structure, except for the orientation of the methyl, methoxy­phenyl and methoxy­carbonyl substituents.

S1. Comment

Podocarpic acid, (I), and its derivatives have been successfully used in medicinal chemistry, particularly as inhibitors of plant cell growth (Soderberg et al., 1996), the influenza virus (Staschke et al., 1998), and antileukemic and anti-inflammatory agents (Parish & Miles, 1984). Several diterpenoid quinone taxodines and maytenoquinones obtained from podocarpic acid also exhibit anticancer activity (Burnell et al., 1988). In order to develop a new stereocontrolled route for the synthesis of (I) using easily accessible 7-methoxy-1-tetralone as the starting material, the title tricyclic keto-diester, (II), has been synthesized. This keto-diester possesses the requisite structural features for a potential intermediate in a total synthesis of (I). To establish the regio- and stereospecificities of the reaction and to build up a hierarchy for such systems, the X-ray structure analysis of (II) was undertaken.

The molecules of (II) consist of three fused six-membered rings (Fig. 1). The cyclohexane ring (ring A; atoms C10A/C1—C4/C4A), with puckering parameters (Cremer & Pople, 1975) Q = 0.552 (2) Å, q₂ = 0.022 (2) Å, q₃ = 0.552 (2) Å and θ = 2.3 (2)°, adopts a chair conformation. Due to the C9═O6 double bond and the adjacent essentially planar fused phenyl ring (ring C; atoms C4B/C5—C8/C8A), the environment of atom C9 is planar, and hence the cyclohexanone ring (ring B; atoms C4A/C4B/C8A/C9/C10/C10A), with puckering parameters Q = 0.485 (2) Å, q₂ = 0.402 (2) Å, q₃ = 0.273 (3) Å and θ = 55.8 (3)°, displays a half-chair conformation. Atom C10A is −0.646 (3) Å from the least-squares plane through the remaining endocyclic atoms of ring B. The torsion angle C11—C4A—C10A—H1 is 53.1°, revealing a cis geometry at ring junction A/B; the dihedral angles between the planar parts of the rings A/B and B/C are 68.6 (8) and 3.7 (8)°, respectively.

The two methoxycarbonyl groups at C1 are in almost antiperiplanar and gauche orientations with respect to the C4A—C10A bond [C13—C1—C10A—C4A = −167.7 (2)° and C15—C1—C10A—C4A = 72.7 (2)°]. The extended conformations of the two O═C—O—CH₃ moieties at C1 are established by the torsion angles C14—O3—C13—C1 of 179.3 (2)° and C16–O5–C15–C1 of −178.5 (2)°. The observed bond lengths and angles (Table 1) agree well with the corresponding values reported for related tricyclic structures (Lazar et al., 2002; Stanković et al., 2002; Cambie et al., 1998).

The crystal structure exhibits intra- and interamolecular C—H···O hydrogen bonds (Table 2). While the intermolecular C3···O4 and C10···O2 interactions (Table 2) influence the conformations of rings A and B, the intermolecular hydrogen bonds result in a complex supramolecular structure. A simplified description of the supramolecular assembly can be visualized in terms of molecular chains and connections among such chains (Fig. 2). The terminal atom C16 at (x, y, z) of one methoxycarbonyl moiety acts as a donor, via H16A, to O1 at (2 − x, y − 1/2, 3/2 − z), thus generating infinite chains parallel to the [211] direction. Additional hydrogen bonds between molecules exist in the chains where atom C14 at (x, y, z) acts as a donor to O4 at (2 − x, y − 1/2, 3/2 − z). Other C—H···O hydrogen bonds, with atom C11 at (x, y, z) acting as a donor, via H11A, to O6 at (x − 1/2, 3/2 − y, 2 − z), and atom C2 at (x, y, z) acting as donor, via H2A, to O6 at (3/2 − x, 1 − y, z − 1/2), crosslink the molecular chains along the [112] and [111] directions to complete the three-dimensional supramolecular network.

The semi-emperical AM1 molecular-orbital calculations of (II) with the energy profile as a function of the torsion angle C4—C4A—C10A—C10 show the heat of formation energy −226.23 kcal mol⁻¹ (1 kcal mol⁻¹ = 4.184 kJ mol⁻¹). A comparison of the molecular conformations of the AM1 optimized and X-ray structures (Fig. 3) reveals a fairly good agreement between the two in respect of the tricyclic skeleton of the molecule. For the substituents at C1, C4A and C6, however, the solid-state conformations differ noticeably from the AM1-calculated conformations. The methyl group at the A/B ring junction, C4A, is antiperiplanar with respect to the C1—C10A bond in (II) [C11—C4A—C10A—C1 = 168.5 (2)°] and gauche in the AM1-optimized structure [corresponding torsion angle = −73.4°]. Compared to the crystallographic observation, the methoxy moiety at C6 is rotated about the C6—O1 bond by 173.7° in the AM1-calculated structure. Similarly, the orientations of the C13—O2 and C15—O4 carbonyl groups with respect to the C1—C10A bond are markedly different in the AM1-calculated structure than those in the solid state. The differences in the molecular conformations between the X-ray and energy-minimized structures for compound (II) are presumably due to intermolecular hydrogen bonds involving the side-chain atoms (Table 2), which influence the packing of the molecules in the crystalline state.

S2. Experimental

A solution of 1-(4,4-dimethoxycarbonylbutyl)-7-methoxy-1-methyl-1,4-dihydronaphthalen-4-one (0.5 g, 1.39 mmol), prepared from 7-methoxy-1-tetralone, in dry tert-butanol (5 ml) was added dropwise under a nitrogen atmosphere to a stirred solution of potassium tert-butoxide [prepared from potassium (0.027 g, 0.69 mmol)] in tert-butanol (5 ml) at 283 K. After stirring at room temperature for 16 h, the reaction mixture was diluted with water (20 ml) and extracted with ether (3 × 25 ml). The ether extract was washed with water, dried and concentrated. The residue was crystallized from a mixture of methyl acetate and light petrolium (1:1) to furnish the title keto-diester, (II) (yield: 0.389 g, 76%; m.p. 431 K). Elemental analysis for C₂₀H₂₄O₆: C 66.65, H 6.71%; found: C 66.47, H 6.83%.

S3. Refinement

Theoritical calculations for the energy-minimized structure of (II) were carried out with the MOPAC 5.0 program package (Stewart, 1988) which included the AM1 Hamiltonian (Dewar et al., 1985). The inital molecular geometries were adopted from standard data incorporated in the package and subsequently fully optimized using an energy gradient method. The refined value of the Flack (1983) parameter [0.1 (8)] was inconclusive (Flack & Bernardinelli, 2000), hence the Friedel equivalents were merged prior to the final refinement. H atoms of the methyl groups, the benzene ring and secondary CH₂ groups were placed geometrically and treated as riding. The H atom on C10A was found in a difference map. The methyl H atoms were constrained using the HFIX 137 instruction (SHELXL97; Sheldrick, 1997), with the C—H distance fixed at 0.96 Å and the H–C–H angle tetrahedral. The H atoms of the benzene ring were fixed using the HFIX 41 instruction and the H atoms of the idealized secondary CH₂ groups were fixed using the HFIX 21 instruction.

Computing details

Data collection: SMART (Bruker, 1998); cell refinement: SMART; data reduction: SAINT (Bruker, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: WinGX (Farrugia, 1999) and CAMERON (Watkin et al., 1996); software used to prepare material for publication: SHELXL97 and PARST (Nardelli, 1995).

Figures

	Fig. 1. A view of the molecule of (II), with displacement ellipsoids at the 30% probability level. H atoms are shown as small spheres of arbitrary radii.
	Fig. 2. Packing diagram for (II), viewed down the a axis. Hydrogen bonds are indicated by dotted lines. H atoms not participating in the hydrogen bonding have been omitted for clarity.
	Fig. 3. Comparison of the AM1-optimized and X-ray stuctures for (II).

Dimethyl 4aβ-methyl-6-methoxy-9-oxo-1,2,3,4,4a,9,10,10aβ- octahydrophenanthrene-1,1-dicarboxylate

Crystal data

C20H24O6	Dx = 1.326 Mg m^−3
Mr = 360.39	Melting point: 431 K
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 4990 reflections
a = 9.491 (4) Å	θ = 2.4–24.9°
b = 13.541 (5) Å	µ = 0.10 mm^−1
c = 14.051 (6) Å	T = 293 K
V = 1805.8 (12) Å^3	Block, colourless
Z = 4	0.40 × 0.30 × 0.25 mm
F(000) = 768

Data collection

Bruker SMART CCD area-detector diffractometer	1913 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.016
Graphite monochromator	θmax = 26.0°, θmin = 2.1°
ϕ and ω scans	h = −11→11
14200 measured reflections	k = −16→16
2041 independent reflections	l = −17→17

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) = 0.096	H-atom parameters constrained
S = 1.10	w = 1/[σ^2(Fo^2) + (0.0633P)^2 + 0.1483P] where P = (Fo^2 + 2Fc^2)/3
2041 reflections	(Δ/σ)max = 0.024
239 parameters	Δρmax = 0.31 e Å^−3
0 restraints	Δρmin = −0.15 e Å^−3

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O1	0.7636 (2)	0.93442 (12)	0.62722 (13)	0.0630 (5)
O2	0.66719 (17)	0.36410 (11)	0.89782 (11)	0.0527 (4)
O3	0.87678 (17)	0.36779 (11)	0.82597 (13)	0.0560 (4)
O4	0.92799 (17)	0.58559 (13)	0.72734 (13)	0.0629 (5)
O5	0.89428 (15)	0.57374 (11)	0.88402 (11)	0.0489 (4)
O6	0.7192 (2)	0.71233 (12)	1.01841 (11)	0.0663 (5)
C1	0.7231 (2)	0.49742 (14)	0.78803 (13)	0.0377 (4)
C2	0.6967 (3)	0.46354 (15)	0.68437 (15)	0.0505 (5)
H2A	0.7832	0.4362	0.6587	0.061*
H2B	0.6264	0.4116	0.6844	0.061*
C3	0.6474 (3)	0.54649 (17)	0.62057 (15)	0.0540 (6)
H3A	0.6275	0.5207	0.5576	0.065*
H3B	0.7215	0.5955	0.6147	0.065*
C4	0.5164 (2)	0.59446 (15)	0.66056 (15)	0.0488 (5)
H4A	0.4408	0.5463	0.6609	0.059*
H4B	0.4884	0.6480	0.6188	0.059*
C4A	0.53461 (18)	0.63541 (14)	0.76175 (14)	0.0381 (4)
C4B	0.63235 (19)	0.72474 (13)	0.76823 (13)	0.0364 (4)
C5	0.6540 (2)	0.78668 (15)	0.69113 (14)	0.0415 (4)
H5	0.6131	0.7716	0.6328	0.050*
C6	0.7362 (2)	0.87093 (15)	0.69994 (17)	0.0477 (5)
C7	0.7970 (3)	0.89506 (16)	0.78679 (19)	0.0546 (5)
H7	0.8521	0.9516	0.7927	0.065*
C8	0.7752 (2)	0.83510 (16)	0.86315 (16)	0.0514 (5)
H8	0.8156	0.8513	0.9214	0.062*
C8A	0.6933 (2)	0.74956 (14)	0.85579 (14)	0.0409 (4)
C9	0.6768 (2)	0.68642 (15)	0.94085 (14)	0.0458 (5)
C10	0.6035 (2)	0.58838 (15)	0.92941 (14)	0.0435 (4)
H10A	0.5097	0.5937	0.9564	0.052*
H10B	0.6544	0.5393	0.9661	0.052*
C10A	0.5902 (2)	0.55137 (14)	0.82712 (13)	0.0362 (4)
C11	0.3881 (2)	0.66906 (18)	0.79588 (19)	0.0541 (5)
H11A	0.3971	0.7031	0.8555	0.081*
H11B	0.3284	0.6124	0.8039	0.081*
H11C	0.3474	0.7126	0.7495	0.081*
C12	0.7158 (4)	0.9088 (2)	0.53487 (19)	0.0725 (8)
H12A	0.7545	0.8460	0.5170	0.109*
H12B	0.7457	0.9582	0.4902	0.109*
H12C	0.6148	0.9049	0.5349	0.109*
C13	0.7491 (2)	0.40323 (14)	0.84554 (14)	0.0402 (4)
C14	0.9186 (3)	0.27936 (18)	0.8753 (2)	0.0665 (7)
H14A	0.9128	0.2901	0.9427	0.100*
H14B	1.0137	0.2629	0.8583	0.100*
H14C	0.8571	0.2261	0.8577	0.100*
C15	0.8599 (2)	0.55814 (14)	0.79327 (16)	0.0424 (5)
C16	1.0188 (2)	0.63208 (18)	0.9029 (2)	0.0679 (7)
H16A	1.0991	0.6011	0.8741	0.102*
H16B	1.0331	0.6368	0.9704	0.102*
H16C	1.0067	0.6970	0.8768	0.102*
H1	0.5111	0.5011	0.8268	0.050*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0758 (11)	0.0457 (8)	0.0676 (10)	−0.0134 (8)	0.0124 (9)	0.0061 (8)
O2	0.0542 (9)	0.0442 (7)	0.0598 (9)	−0.0038 (7)	0.0077 (7)	0.0101 (7)
O3	0.0532 (9)	0.0384 (7)	0.0765 (10)	0.0099 (7)	0.0132 (8)	0.0069 (8)
O4	0.0553 (9)	0.0580 (9)	0.0755 (11)	−0.0080 (8)	0.0209 (8)	0.0100 (9)
O5	0.0397 (7)	0.0449 (8)	0.0619 (9)	−0.0033 (7)	−0.0028 (7)	−0.0077 (7)
O6	0.0979 (13)	0.0566 (9)	0.0445 (8)	0.0124 (10)	−0.0164 (9)	−0.0134 (7)
C1	0.0425 (10)	0.0316 (8)	0.0390 (9)	−0.0003 (8)	0.0054 (8)	−0.0057 (7)
C2	0.0690 (13)	0.0399 (10)	0.0428 (11)	−0.0024 (10)	0.0058 (10)	−0.0096 (9)
C3	0.0780 (15)	0.0490 (11)	0.0352 (9)	−0.0099 (12)	−0.0001 (10)	−0.0050 (9)
C4	0.0565 (12)	0.0445 (10)	0.0453 (10)	−0.0141 (10)	−0.0129 (9)	0.0031 (9)
C4A	0.0343 (9)	0.0378 (9)	0.0421 (9)	−0.0026 (8)	−0.0018 (7)	0.0037 (8)
C4B	0.0330 (8)	0.0338 (8)	0.0423 (9)	0.0035 (7)	0.0007 (7)	−0.0035 (8)
C5	0.0409 (9)	0.0384 (9)	0.0451 (10)	0.0003 (8)	0.0022 (8)	−0.0022 (8)
C6	0.0449 (11)	0.0348 (10)	0.0633 (12)	−0.0003 (8)	0.0096 (10)	−0.0006 (9)
C7	0.0508 (11)	0.0368 (10)	0.0760 (15)	−0.0055 (9)	−0.0033 (11)	−0.0100 (10)
C8	0.0541 (11)	0.0410 (10)	0.0590 (12)	0.0034 (10)	−0.0106 (10)	−0.0156 (9)
C8A	0.0416 (9)	0.0354 (9)	0.0456 (10)	0.0071 (8)	−0.0017 (8)	−0.0088 (8)
C9	0.0541 (11)	0.0454 (10)	0.0380 (9)	0.0150 (9)	−0.0018 (9)	−0.0099 (9)
C10	0.0479 (10)	0.0449 (10)	0.0376 (9)	0.0097 (9)	0.0063 (8)	−0.0007 (9)
C10A	0.0365 (9)	0.0361 (9)	0.0358 (9)	−0.0013 (7)	0.0019 (7)	0.0006 (7)
C11	0.0369 (10)	0.0529 (12)	0.0725 (14)	0.0020 (9)	−0.0005 (10)	0.0110 (11)
C12	0.0918 (19)	0.0611 (15)	0.0644 (15)	−0.0108 (15)	0.0189 (14)	0.0125 (13)
C13	0.0454 (10)	0.0329 (9)	0.0424 (10)	−0.0017 (8)	0.0017 (9)	−0.0064 (8)
C14	0.0644 (14)	0.0438 (12)	0.0912 (18)	0.0111 (11)	−0.0002 (15)	0.0080 (13)
C15	0.0412 (10)	0.0309 (9)	0.0551 (11)	0.0044 (8)	0.0086 (9)	−0.0022 (8)
C16	0.0444 (11)	0.0521 (12)	0.107 (2)	−0.0047 (11)	−0.0150 (13)	−0.0121 (14)

Geometric parameters (Å, º)

O1—C6	1.361 (3)	C4B—C8A	1.401 (3)
O1—C12	1.418 (3)	C5—C6	1.387 (3)
O2—C13	1.194 (2)	C5—H5	0.9300
O3—C13	1.332 (3)	C6—C7	1.389 (3)
O3—C14	1.439 (3)	C7—C8	1.361 (3)
O4—C15	1.189 (3)	C7—H7	0.9300
O5—C15	1.333 (3)	C8—C8A	1.399 (3)
O5—C16	1.446 (3)	C8—H8	0.9300
O6—C9	1.213 (3)	C8A—C9	1.478 (3)
C1—C13	1.530 (3)	C9—C10	1.508 (3)
C1—C15	1.538 (3)	C10—C10A	1.527 (3)
C1—C2	1.547 (3)	C10—H10A	0.9700
C1—C10A	1.558 (3)	C10—H10B	0.9700
C2—C3	1.511 (3)	C10A—H1	1.0132
C2—H2A	0.9700	C11—H11A	0.9600
C2—H2B	0.9700	C11—H11B	0.9600
C3—C4	1.511 (4)	C11—H11C	0.9600
C3—H3A	0.9700	C12—H12A	0.9600
C3—H3B	0.9700	C12—H12B	0.9600
C4—C4A	1.536 (3)	C12—H12C	0.9600
C4—H4A	0.9700	C14—H14A	0.9600
C4—H4B	0.9700	C14—H14B	0.9600
C4A—C4B	1.527 (3)	C14—H14C	0.9600
C4A—C11	1.540 (3)	C16—H16A	0.9600
C4A—C10A	1.555 (3)	C16—H16B	0.9600
C4B—C5	1.386 (3)	C16—H16C	0.9600
C6—O1—C12	118.11 (18)	C8—C8A—C4B	119.56 (19)
C13—O3—C14	116.83 (18)	C8—C8A—C9	118.57 (18)
C15—O5—C16	117.5 (2)	C4B—C8A—C9	121.85 (18)
C13—C1—C15	106.50 (16)	O6—C9—C8A	121.6 (2)
C13—C1—C2	106.02 (15)	O6—C9—C10	120.2 (2)
C15—C1—C2	109.88 (17)	C8A—C9—C10	118.17 (17)
C13—C1—C10A	109.59 (15)	C9—C10—C10A	115.30 (16)
C15—C1—C10A	114.58 (15)	C9—C10—H10A	108.4
C2—C1—C10A	109.87 (17)	C10A—C10—H10A	108.4
C3—C2—C1	112.83 (16)	C9—C10—H10B	108.4
C3—C2—H2A	109.0	C10A—C10—H10B	108.4
C1—C2—H2A	109.0	H10A—C10—H10B	107.5
C3—C2—H2B	109.0	C10—C10A—C4A	110.10 (15)
C1—C2—H2B	109.0	C10—C10A—C1	114.76 (16)
H2A—C2—H2B	107.8	C4A—C10A—C1	114.18 (15)
C2—C3—C4	110.72 (18)	C10—C10A—H1	106.6
C2—C3—H3A	109.5	C4A—C10A—H1	103.8
C4—C3—H3A	109.5	C1—C10A—H1	106.5
C2—C3—H3B	109.5	C4A—C11—H11A	109.5
C4—C3—H3B	109.5	C4A—C11—H11B	109.5
H3A—C3—H3B	108.1	H11A—C11—H11B	109.5
C3—C4—C4A	114.00 (17)	C4A—C11—H11C	109.5
C3—C4—H4A	108.8	H11A—C11—H11C	109.5
C4A—C4—H4A	108.8	H11B—C11—H11C	109.5
C3—C4—H4B	108.8	O1—C12—H12A	109.5
C4A—C4—H4B	108.8	O1—C12—H12B	109.5
H4A—C4—H4B	107.6	H12A—C12—H12B	109.5
C4B—C4A—C4	114.18 (15)	O1—C12—H12C	109.5
C4B—C4A—C11	107.20 (16)	H12A—C12—H12C	109.5
C4—C4A—C11	107.06 (17)	H12B—C12—H12C	109.5
C4B—C4A—C10A	109.79 (15)	O2—C13—O3	124.03 (19)
C4—C4A—C10A	108.71 (15)	O2—C13—C1	126.15 (18)
C11—C4A—C10A	109.81 (17)	O3—C13—C1	109.76 (16)
C5—C4B—C8A	118.70 (17)	O3—C14—H14A	109.5
C5—C4B—C4A	121.54 (17)	O3—C14—H14B	109.5
C8A—C4B—C4A	119.58 (17)	H14A—C14—H14B	109.5
C4B—C5—C6	120.76 (19)	O3—C14—H14C	109.5
C4B—C5—H5	119.6	H14A—C14—H14C	109.5
C6—C5—H5	119.6	H14B—C14—H14C	109.5
O1—C6—C5	124.1 (2)	O4—C15—O5	124.2 (2)
O1—C6—C7	115.56 (19)	O4—C15—C1	126.0 (2)
C5—C6—C7	120.4 (2)	O5—C15—C1	109.71 (17)
C8—C7—C6	119.27 (19)	O5—C16—H16A	109.5
C8—C7—H7	120.4	O5—C16—H16B	109.5
C6—C7—H7	120.4	H16A—C16—H16B	109.5
C7—C8—C8A	121.3 (2)	O5—C16—H16C	109.5
C7—C8—H8	119.3	H16A—C16—H16C	109.5
C8A—C8—H8	119.3	H16B—C16—H16C	109.5
C13—C1—C2—C3	171.31 (19)	C9—C10—C10A—C4A	−47.7 (2)
C15—C1—C2—C3	−74.0 (2)	C9—C10—C10A—C1	82.8 (2)
C10A—C1—C2—C3	53.0 (2)	C4B—C4A—C10A—C10	56.9 (2)
C1—C2—C3—C4	−56.0 (3)	C4—C4A—C10A—C10	−177.55 (16)
C2—C3—C4—C4A	57.5 (2)	C11—C4A—C10A—C10	−60.7 (2)
C3—C4—C4A—C4B	68.6 (2)	C4B—C4A—C10A—C1	−73.88 (19)
C3—C4—C4A—C11	−172.90 (18)	C4—C4A—C10A—C1	51.7 (2)
C3—C4—C4A—C10A	−54.3 (2)	C11—C4A—C10A—C1	168.49 (17)
C4—C4A—C4B—C5	25.3 (3)	C13—C1—C10A—C10	63.8 (2)
C11—C4A—C4B—C5	−93.1 (2)	C15—C1—C10A—C10	−55.8 (2)
C10A—C4A—C4B—C5	147.67 (17)	C2—C1—C10A—C10	179.95 (16)
C4—C4A—C4B—C8A	−159.71 (17)	C13—C1—C10A—C4A	−167.70 (15)
C11—C4A—C4B—C8A	81.9 (2)	C15—C1—C10A—C4A	72.7 (2)
C10A—C4A—C4B—C8A	−37.3 (2)	C2—C1—C10A—C4A	−51.6 (2)
C8A—C4B—C5—C6	0.9 (3)	C14—O3—C13—O2	−3.1 (3)
C4A—C4B—C5—C6	175.93 (17)	C14—O3—C13—C1	179.35 (18)
C12—O1—C6—C5	−5.7 (3)	C15—C1—C13—O2	139.6 (2)
C12—O1—C6—C7	174.1 (2)	C2—C1—C13—O2	−103.4 (2)
C4B—C5—C6—O1	179.1 (2)	C10A—C1—C13—O2	15.2 (3)
C4B—C5—C6—C7	−0.6 (3)	C15—C1—C13—O3	−42.9 (2)
O1—C6—C7—C8	−179.7 (2)	C2—C1—C13—O3	74.1 (2)
C5—C6—C7—C8	0.0 (3)	C10A—C1—C13—O3	−167.34 (16)
C6—C7—C8—C8A	0.3 (3)	C16—O5—C15—O4	3.2 (3)
C7—C8—C8A—C4B	0.0 (3)	C16—O5—C15—C1	−178.45 (16)
C7—C8—C8A—C9	178.5 (2)	C13—C1—C15—O4	122.6 (2)
C5—C4B—C8A—C8	−0.6 (3)	C2—C1—C15—O4	8.1 (3)
C4A—C4B—C8A—C8	−175.74 (17)	C10A—C1—C15—O4	−116.1 (2)
C5—C4B—C8A—C9	−179.02 (17)	C13—C1—C15—O5	−55.72 (19)
C4A—C4B—C8A—C9	5.9 (3)	C2—C1—C15—O5	−170.13 (16)
C8—C8A—C9—O6	8.2 (3)	C10A—C1—C15—O5	65.6 (2)
C4B—C8A—C9—O6	−173.4 (2)	H1—C10A—C1—C13	−53.8
C8—C8A—C9—C10	−172.70 (18)	H1—C10A—C1—C15	−173.5
C4B—C8A—C9—C10	5.7 (3)	H1—C10A—C4A—C11	53.0
O6—C9—C10—C10A	−164.4 (2)	C5—C6—O1—C12	−5.7 (3)
C8A—C9—C10—C10A	16.5 (3)	C7—C6—O1—C12	174.1 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3B···O4	0.97	2.52	3.102 (3)	118
C10—H10B···O2	0.97	2.56	3.128 (3)	117
C11—H11A···O6^i	0.96	2.70	3.458 (3)	136
C2—H2A···O6^ii	0.97	2.82	3.427 (3)	122
C16—H16A···O1^iii	0.96	2.61	3.407 (3)	141
C14—H14B···O4^iii	0.96	2.74	3.329 (3)	120

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