(-)-Dimenthyl malonate

The title compound, bis(2-iso­propyl-5-methyl­cyclo­hex-1-yl) malonate, C₂₃H₄₀O₄, crystallizes in the monoclinic space group P2₁. In the crystal, the mol­ecule is not C₂ symmetric.

S1. Comment

A large number of substituted malonic acid derivatives are known (Kanters & Kroon, 1972). Some attention has been focused on related keto (Adhikesavalu & Venkatesan, 1983) and aldehyde derivatives (Lundgren & Aurivillius, 1964), but little attention has been paid to the corresponding malonate ester derivatives. We were originally interested in the conformational preference of simple 1,3-dicarbonyl-containing molecules. To this aim, we synthesized the title C₂-symmetric dimenthyl malonate, (III), as our model compound. We chose the enantiopure (-)-menthol, (I), as our ester scaffold, as this would lead directly to enantiopure C₂-symmetric (III) without contamination resulting from the formation of other stereoisomers. Addition of commercially available malonyl dichloride, (II), to a stirred solution of natural (-)-menthol and triethylamine in dichloromethane gave the required (-)-dimenthyl malonate, (III), as a cream-coloured precipitate in good yield (66%). The crude product was purified by flash column chromatography on silica gel, eluting with light petroleum (313–333 K)-ether (19:1) mixture, and was then vapour recrystallized from hexane to give colourless needle-like crystals of (III). \sch

X-ray diffraction of (III) revealed its structure, illustrated in Fig. 1. The stereochemistry was assigned by reference to (-)-menthol. It was immediately evident that this molecule was not C₂ symmetric in its solid phase, due to the non-equivalence of the carbonyl groups C1═O4 and C3═O3. By comparison, solution phase NMR studies at room temperature are consistent with C₂ symmetry. We ascribe the conformation of this molecule in the crystal state to packing effects. The overall unit cell is pseudo C₂ symmetric and contains two identical malonate molecules, as shown in Fig. 2.

The molecule is certainly not an enol derivative, with a C1—C2—C3 bond angle of 111.5 (5)° and not significantly different C1—C2 and C2—C3 bond lengths of 1.492 (7) and 1.497 (8) Å, respectively (Table 1). All the substituents on the cyclohexyl ring are in the expected equatorial position.

The most striking structural feature is the relative conformation of both carbonyl groups, C1═O4 and C3═O3. They are clearly twisted away from each other, as shown by the torsion angles of 138.3 (6)° for O4—C1—C2—O3 and 102.6 (6)° for C1—C2—C3—O3. This is presumably due to a combination of hyperconjugation effects at C2—H with both carbonyl groups and a minimization of their relative dipole moments. This can also be seen in a related twist involving the other O atom in the ester motif, as shown by the torsion angles of -42.5 (6)° for O1—C1—C2—C3 and -73.4 (6)° for C1—C2—C3—O2. In contrast, both the ester groups strive for planarity [-9.5 (7)° for C4—O2—C3—O3 and -0.8 (8)° for C14—O1—C1—O4] through anomeric assistance (Table 1).

This type of anti-parallel alignment has been reported in the structural arrangement of diimidazolines (Brennan & McKee, 1999), diones (Klein et al., 1999) and related malonic acid derivatives (Kalsbeek, 1992). The effect of the non-equivalence of the menthyl groups is more interesting and can be seen more clearly by the non-equivalence of the ester groups. The torsion angle of the ester group C14—O1—C1—C2 is planar [-180.0 (4)°], whereas the related ester grouping C4—O2—C3—C2 certainly has a slight twist [166.6 (4)°] (Table 1). This is more than likely due to a combination of crystal-packing effects and the presence of a local pseudo twofold axis (Table 2 and Fig. 2). This layer sequence is positioned in an ABAB system, with layer B oriented anti-parallel to layer A.

S2. Experimental

Malonyl dichloride (5.0 g, 3.45 ml, 35.5 mmol) was slowly added to a stirred solution of triethylamine (7.1 g, 9.90 ml, 70.9 mmol) and (-)-menthol (11.1 g, 70.9 mmol) in dichloromethane (100 ml), and the resulting solution was stirred for 1 h. The reaction was quenched slowly with water (30 ml) and the organic layer was extracted with diethyl ether (3 × 50 ml), dried (MgSO₄) and evaporated under reduced pressure. The residue was purified by flash column chromatography on silica gel, eluting with light petroleum (313–333 K)-ether (19:1) to give the title compound, (III) (9.0 g, 66%), as light-cream solid. This solid was recrystallized using hexane to give colourless needle crystals (m.p. 327–328 K) Prism given as shape below. Spectroscopic analysis: R_f [light petroleum (313–333 K):ether (9:1)] 0.75; IR (ν_max, film, cm^-1): 1725 (CO); [α]_D -83.7 (c. 2.7 in acetone); ¹H NMR (250 MHz, CDCl₃, δ, p.p.m.): 4.8 (2H, td, J = 10.8 and 4.4 Hz, CHO), 3.36 (2H, s, CH₂CO), 2.15–0.85 (18H, m, 6 × CH₂ and 6 × CH), 1.1–0.95 (6H, m, 2 × CH₃), 0.85 (3H, d, J = 7.0 Hz, CHCH₃); ¹³C NMR (67 MHz, CDCl₃, δ, p.p.m.): 166.2, 75.5, 46.9, 42.4, 40.7, 34.2, 31.4, 26.1, 23.4, 22.0, 20.8, 16.3; analysis found M⁺ 381.3017; C₂₃H₄₁O₄ requires M⁺ 381.3005; MS (m/z): 381 (80%, M), 243 (100, M - C₁₀H₁₈).

S3. Refinement

H atoms were placed in geometrical positions, with C—H = 0.98–1.0 Å. U_iso was refined for the H atoms on C2; other H atoms were treated as riding, with U_iso(H) = 1.2 or 1.5U_eq(C). Are these the correct restraints?

Computing details

Data collection: CAD-4-PC Software (Enraf Nonius, 1994); cell refinement: CAD-4-PC Software; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

	Fig. 1. A view of the molecule of (III) with 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. A packing diagram for (III), viewed along the b axis.

Bis(2-isopropyl-5-methylcyclohex-1-yl) malonate

Crystal data

C23H40O4	F(000) = 420
Mr = 380.55	Dx = 1.112 Mg m^−3
Monoclinic, P21	Mo Kα radiation, λ = 0.71069 Å
a = 12.990 (2) Å	Cell parameters from 25 reflections
b = 6.092 (3) Å	θ = 8.6–13.4°
c = 14.528 (2) Å	µ = 0.07 mm^−1
β = 98.55 (2)°	T = 180 K
V = 1136.9 (6) Å^3	Prism, colourless
Z = 2	0.2 × 0.2 × 0.2 mm

Data collection

Enraf Nonius CAD-4 diffractometer	θmax = 25.0°, θmin = 1.4°
non–profiled ω/2θ scans	h = −15→15
2285 measured reflections	k = 0→7
2194 independent reflections	l = 0→17
1234 reflections with I > 2σ(I)	2 standard reflections every 60 min
Rint = 0.049	intensity decay: 7%

Refinement

Refinement on F^2	1 restraint
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F^2 > 2σ(F^2)] = 0.058	w = 1/[σ^2(Fo^2) + (0.096P)^2] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.163	(Δ/σ)max = 0.003
S = 0.93	Δρmax = 0.22 e Å^−3
2194 reflections	Δρmin = −0.21 e Å^−3
251 parameters

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.

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

	x	y	z	Uiso*/Ueq
O1	0.5999 (3)	0.6974 (7)	0.8711 (3)	0.0421 (10)
O2	0.3567 (3)	0.7307 (6)	0.7709 (2)	0.0354 (9)
O3	0.3775 (3)	0.5342 (8)	0.9031 (3)	0.0529 (12)
O4	0.5993 (3)	1.0556 (8)	0.8439 (4)	0.0710 (15)
C1	0.5590 (4)	0.8948 (11)	0.8681 (4)	0.0346 (13)
C2	0.4554 (4)	0.8918 (11)	0.9007 (4)	0.0377 (14)
H2A	0.4175	1.0289	0.8808	0.039 (11)*
H2B	0.4654	0.8862	0.9695	0.039 (11)*
C3	0.3917 (4)	0.6988 (11)	0.8624 (3)	0.0368 (14)
C4	0.3127 (4)	0.5403 (9)	0.7159 (3)	0.0301 (13)
H4	0.2753	0.4445	0.756	0.036*
C5	0.2351 (4)	0.6284 (9)	0.6363 (3)	0.0304 (13)
H5	0.2741	0.7299	0.5998	0.036*
C6	0.1978 (4)	0.4338 (10)	0.5718 (4)	0.0402 (15)
H6A	0.1573	0.331	0.6052	0.048*
H6B	0.1512	0.4891	0.5165	0.048*
C7	0.2883 (4)	0.3117 (10)	0.5403 (4)	0.0450 (16)
H7A	0.261	0.1886	0.4993	0.054*
H7B	0.3262	0.4123	0.5036	0.054*
C8	0.3631 (4)	0.2228 (10)	0.6213 (4)	0.0401 (14)
H8	0.3244	0.1175	0.6565	0.048*
C9	0.4011 (4)	0.4129 (10)	0.6858 (4)	0.0380 (14)
H9A	0.4459	0.3547	0.7416	0.046*
H9B	0.4439	0.5128	0.6533	0.046*
C10	0.4551 (5)	0.1026 (11)	0.5911 (4)	0.0551 (18)
H10A	0.4919	0.2013	0.5538	0.083*
H10B	0.43	−0.0258	0.5537	0.083*
H10C	0.5026	0.055	0.6462	0.083*
C11	0.1464 (4)	0.7608 (10)	0.6667 (3)	0.0359 (14)
H11	0.1787	0.8811	0.7081	0.043*
C12	0.0766 (4)	0.6287 (12)	0.7227 (4)	0.0558 (19)
H12A	0.1194	0.5615	0.7766	0.084*
H12B	0.0406	0.5135	0.6832	0.084*
H12C	0.0252	0.7266	0.7441	0.084*
C13	0.0783 (5)	0.8700 (11)	0.5842 (4)	0.0477 (16)
H13A	0.0393	0.7572	0.5455	0.072*
H13B	0.1225	0.9512	0.547	0.072*
H13C	0.0295	0.9715	0.6074	0.072*
C14	0.7019 (4)	0.6626 (10)	0.8422 (4)	0.0334 (14)
H14	0.7333	0.8065	0.8284	0.04*
C15	0.6828 (4)	0.5236 (10)	0.7551 (4)	0.0381 (14)
H15A	0.6415	0.609	0.7046	0.046*
H15B	0.6416	0.3927	0.7672	0.046*
C16	0.7843 (4)	0.4500 (10)	0.7238 (4)	0.0398 (15)
H16	0.8214	0.582	0.7044	0.048*
C17	0.8530 (5)	0.3378 (10)	0.8030 (4)	0.0425 (16)
H17A	0.9207	0.3015	0.7832	0.051*
H17B	0.8198	0.1988	0.8182	0.051*
C18	0.8713 (4)	0.4814 (11)	0.8888 (4)	0.0426 (16)
H18A	0.9095	0.615	0.8748	0.051*
H18B	0.9153	0.4011	0.9393	0.051*
C19	0.7701 (4)	0.5483 (9)	0.9221 (3)	0.0293 (12)
H19	0.7335	0.4102	0.9355	0.035*
C20	0.7855 (4)	0.6864 (10)	1.0129 (3)	0.0411 (15)
H20	0.7145	0.7185	1.0285	0.049*
C21	0.8435 (5)	0.5582 (12)	1.0943 (4)	0.0583 (18)
H21A	0.8431	0.6415	1.1519	0.087*
H21B	0.9155	0.5342	1.084	0.087*
H21C	0.8093	0.4162	1.0993	0.087*
C22	0.8379 (5)	0.9049 (12)	1.0031 (4)	0.0492 (16)
H22A	0.9057	0.8807	0.983	0.074*
H22B	0.8476	0.9812	1.0631	0.074*
H22C	0.7942	0.9945	0.9567	0.074*
C23	0.7612 (5)	0.2933 (12)	0.6404 (4)	0.061 (2)
H23A	0.7249	0.1631	0.6588	0.091*
H23B	0.8267	0.249	0.62	0.091*
H23C	0.7172	0.3681	0.5892	0.091*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.037 (2)	0.034 (3)	0.058 (2)	0.001 (2)	0.0139 (18)	0.002 (2)
O2	0.042 (2)	0.035 (2)	0.0265 (18)	−0.0040 (19)	−0.0027 (15)	0.0043 (18)
O3	0.057 (3)	0.062 (3)	0.038 (2)	−0.012 (2)	0.0010 (19)	0.019 (2)
O4	0.057 (3)	0.048 (3)	0.110 (4)	0.005 (3)	0.019 (3)	0.026 (3)
C1	0.039 (3)	0.026 (4)	0.035 (3)	−0.001 (3)	−0.007 (2)	0.003 (3)
C2	0.039 (3)	0.042 (4)	0.029 (3)	0.001 (3)	−0.003 (2)	−0.017 (3)
C3	0.035 (3)	0.053 (4)	0.022 (3)	0.009 (3)	0.002 (2)	0.002 (3)
C4	0.039 (3)	0.021 (3)	0.028 (3)	−0.009 (3)	−0.001 (2)	0.005 (3)
C5	0.038 (3)	0.026 (3)	0.026 (3)	−0.006 (3)	0.002 (2)	0.009 (2)
C6	0.050 (4)	0.036 (4)	0.033 (3)	−0.016 (3)	0.000 (3)	−0.005 (3)
C7	0.056 (4)	0.036 (4)	0.044 (4)	−0.008 (3)	0.008 (3)	−0.012 (3)
C8	0.047 (3)	0.023 (3)	0.053 (3)	−0.006 (3)	0.014 (3)	−0.001 (3)
C9	0.042 (3)	0.034 (4)	0.038 (3)	−0.008 (3)	0.006 (3)	0.005 (3)
C10	0.064 (4)	0.042 (4)	0.060 (4)	0.001 (4)	0.011 (3)	−0.008 (3)
C11	0.026 (3)	0.045 (4)	0.036 (3)	−0.006 (3)	0.000 (2)	0.000 (3)
C12	0.050 (4)	0.069 (5)	0.054 (4)	0.001 (4)	0.023 (3)	0.007 (4)
C13	0.049 (3)	0.043 (4)	0.048 (4)	0.012 (3)	−0.001 (3)	0.007 (3)
C14	0.022 (3)	0.034 (4)	0.046 (3)	−0.005 (2)	0.011 (2)	0.003 (3)
C15	0.040 (3)	0.032 (4)	0.041 (3)	−0.010 (3)	0.001 (2)	0.008 (3)
C16	0.055 (4)	0.033 (4)	0.034 (3)	−0.013 (3)	0.015 (3)	0.005 (3)
C17	0.057 (4)	0.033 (4)	0.040 (3)	0.004 (3)	0.018 (3)	−0.001 (3)
C18	0.039 (3)	0.054 (4)	0.036 (3)	0.005 (3)	0.010 (3)	0.000 (3)
C19	0.033 (3)	0.025 (3)	0.031 (3)	−0.001 (3)	0.010 (2)	−0.004 (3)
C20	0.052 (3)	0.040 (4)	0.034 (3)	0.000 (3)	0.015 (3)	−0.002 (3)
C21	0.091 (5)	0.048 (4)	0.036 (3)	0.000 (4)	0.010 (3)	−0.002 (3)
C22	0.057 (4)	0.050 (4)	0.039 (3)	−0.016 (4)	0.002 (3)	−0.001 (3)
C23	0.076 (5)	0.077 (6)	0.031 (3)	0.001 (4)	0.014 (3)	−0.013 (3)

Geometric parameters (Å, º)

O1—C1	1.313 (7)	C12—H12B	0.98
O1—C14	1.463 (6)	C12—H12C	0.98
O2—C3	1.353 (6)	C13—H13A	0.98
O2—C4	1.475 (6)	C13—H13B	0.98
O3—C3	1.192 (7)	C13—H13C	0.98
O4—C1	1.188 (7)	C14—C15	1.511 (7)
C1—C2	1.492 (7)	C14—C19	1.521 (7)
C2—C3	1.497 (8)	C14—H14	1.0
C2—H2A	0.99	C15—C16	1.525 (8)
C2—H2B	0.99	C15—H15A	0.99
C4—C9	1.504 (7)	C15—H15B	0.99
C4—C5	1.515 (6)	C16—C17	1.510 (7)
C4—H4	1.0	C16—C23	1.537 (8)
C5—C11	1.525 (7)	C16—H16	1.0
C5—C6	1.544 (7)	C17—C18	1.513 (8)
C5—H5	1.0	C17—H17A	0.99
C6—C7	1.519 (8)	C17—H17B	0.99
C6—H6A	0.99	C18—C19	1.522 (7)
C6—H6B	0.99	C18—H18A	0.99
C7—C8	1.511 (8)	C18—H18B	0.99
C7—H7A	0.99	C19—C20	1.553 (7)
C7—H7B	0.99	C19—H19	1.0
C8—C10	1.521 (8)	C20—C22	1.512 (8)
C8—C9	1.525 (8)	C20—C21	1.520 (8)
C8—H8	1.0	C20—H20	1.0
C9—H9A	0.99	C21—H21A	0.98
C9—H9B	0.99	C21—H21B	0.98
C10—H10A	0.98	C21—H21C	0.98
C10—H10B	0.98	C22—H22A	0.98
C10—H10C	0.98	C22—H22B	0.98
C11—C13	1.532 (7)	C22—H22C	0.98
C11—C12	1.533 (7)	C23—H23A	0.98
C11—H11	1.0	C23—H23B	0.98
C12—H12A	0.98	C23—H23C	0.98
C1—O1—C14	120.1 (4)	H12B—C12—H12C	109.5
C3—O2—C4	117.7 (4)	C11—C13—H13A	109.5
O4—C1—O1	124.8 (5)	C11—C13—H13B	109.5
O4—C1—C2	124.2 (6)	H13A—C13—H13B	109.5
O1—C1—C2	111.0 (5)	C11—C13—H13C	109.5
C1—C2—C3	111.5 (5)	H13A—C13—H13C	109.5
C1—C2—H2A	109.3	H13B—C13—H13C	109.5
C3—C2—H2A	109.3	O1—C14—C15	106.2 (4)
C1—C2—H2B	109.3	O1—C14—C19	107.3 (4)
C3—C2—H2B	109.3	C15—C14—C19	112.7 (5)
H2A—C2—H2B	108	O1—C14—H14	110.2
O3—C3—O2	123.7 (6)	C15—C14—H14	110.2
O3—C3—C2	126.4 (5)	C19—C14—H14	110.2
O2—C3—C2	109.8 (5)	C14—C15—C16	111.9 (4)
O2—C4—C9	108.2 (4)	C14—C15—H15A	109.2
O2—C4—C5	107.2 (4)	C16—C15—H15A	109.2
C9—C4—C5	114.3 (4)	C14—C15—H15B	109.2
O2—C4—H4	109	C16—C15—H15B	109.2
C9—C4—H4	109	H15A—C15—H15B	107.9
C5—C4—H4	109	C17—C16—C15	110.2 (4)
C4—C5—C11	114.3 (4)	C17—C16—C23	110.1 (5)
C4—C5—C6	107.7 (4)	C15—C16—C23	110.0 (5)
C11—C5—C6	113.5 (4)	C17—C16—H16	108.9
C4—C5—H5	106.9	C15—C16—H16	108.9
C11—C5—H5	106.9	C23—C16—H16	108.9
C6—C5—H5	106.9	C16—C17—C18	111.6 (5)
C7—C6—C5	111.8 (4)	C16—C17—H17A	109.3
C7—C6—H6A	109.3	C18—C17—H17A	109.3
C5—C6—H6A	109.3	C16—C17—H17B	109.3
C7—C6—H6B	109.3	C18—C17—H17B	109.3
C5—C6—H6B	109.3	H17A—C17—H17B	108
H6A—C6—H6B	107.9	C17—C18—C19	112.3 (5)
C8—C7—C6	112.2 (5)	C17—C18—H18A	109.1
C8—C7—H7A	109.2	C19—C18—H18A	109.1
C6—C7—H7A	109.2	C17—C18—H18B	109.1
C8—C7—H7B	109.2	C19—C18—H18B	109.1
C6—C7—H7B	109.2	H18A—C18—H18B	107.9
H7A—C7—H7B	107.9	C14—C19—C18	108.3 (4)
C7—C8—C10	112.9 (5)	C14—C19—C20	112.8 (4)
C7—C8—C9	108.6 (5)	C18—C19—C20	114.0 (4)
C10—C8—C9	110.2 (5)	C14—C19—H19	107.1
C7—C8—H8	108.3	C18—C19—H19	107.1
C10—C8—H8	108.3	C20—C19—H19	107.1
C9—C8—H8	108.3	C22—C20—C21	110.4 (5)
C4—C9—C8	112.3 (4)	C22—C20—C19	113.5 (4)
C4—C9—H9A	109.2	C21—C20—C19	111.6 (5)
C8—C9—H9A	109.2	C22—C20—H20	107
C4—C9—H9B	109.2	C21—C20—H20	107
C8—C9—H9B	109.2	C19—C20—H20	107
H9A—C9—H9B	107.9	C20—C21—H21A	109.5
C8—C10—H10A	109.5	C20—C21—H21B	109.5
C8—C10—H10B	109.5	H21A—C21—H21B	109.5
H10A—C10—H10B	109.5	C20—C21—H21C	109.5
C8—C10—H10C	109.5	H21A—C21—H21C	109.5
H10A—C10—H10C	109.5	H21B—C21—H21C	109.5
H10B—C10—H10C	109.5	C20—C22—H22A	109.5
C5—C11—C13	112.1 (4)	C20—C22—H22B	109.5
C5—C11—C12	114.1 (5)	H22A—C22—H22B	109.5
C13—C11—C12	108.9 (4)	C20—C22—H22C	109.5
C5—C11—H11	107.1	H22A—C22—H22C	109.5
C13—C11—H11	107.1	H22B—C22—H22C	109.5
C12—C11—H11	107.1	C16—C23—H23A	109.5
C11—C12—H12A	109.5	C16—C23—H23B	109.5
C11—C12—H12B	109.5	H23A—C23—H23B	109.5
H12A—C12—H12B	109.5	C16—C23—H23C	109.5
C11—C12—H12C	109.5	H23A—C23—H23C	109.5
H12A—C12—H12C	109.5	H23B—C23—H23C	109.5
C14—O1—C1—O4	−0.8 (8)	C4—C5—C11—C13	172.8 (5)
C14—O1—C1—C2	−180.0 (4)	C6—C5—C11—C13	−63.1 (6)
O4—C1—C2—C3	138.3 (6)	C4—C5—C11—C12	−62.8 (6)
O1—C1—C2—C3	−42.5 (6)	C6—C5—C11—C12	61.3 (6)
C4—O2—C3—O3	−9.5 (7)	C1—O1—C14—C15	−113.5 (5)
C4—O2—C3—C2	166.6 (4)	C1—O1—C14—C19	125.7 (5)
C1—C2—C3—O3	102.6 (6)	O1—C14—C15—C16	−172.8 (4)
C1—C2—C3—O2	−73.4 (6)	C19—C14—C15—C16	−55.7 (6)
C3—O2—C4—C9	−83.6 (5)	C14—C15—C16—C17	53.6 (6)
C3—O2—C4—C5	152.7 (4)	C14—C15—C16—C23	175.1 (5)
O2—C4—C5—C11	−59.2 (5)	C15—C16—C17—C18	−54.5 (6)
C9—C4—C5—C11	−179.1 (4)	C23—C16—C17—C18	−176.0 (5)
O2—C4—C5—C6	173.6 (4)	C16—C17—C18—C19	57.7 (6)
C9—C4—C5—C6	53.8 (6)	O1—C14—C19—C18	172.1 (4)
C4—C5—C6—C7	−54.5 (6)	C15—C14—C19—C18	55.6 (6)
C11—C5—C6—C7	177.9 (4)	O1—C14—C19—C20	−60.7 (5)
C5—C6—C7—C8	58.8 (6)	C15—C14—C19—C20	−177.2 (4)
C6—C7—C8—C10	−179.2 (5)	C17—C18—C19—C14	−56.4 (6)
C6—C7—C8—C9	−56.7 (6)	C17—C18—C19—C20	177.1 (5)
O2—C4—C9—C8	−175.1 (4)	C14—C19—C20—C22	−60.9 (6)
C5—C4—C9—C8	−55.8 (6)	C18—C19—C20—C22	63.1 (6)
C7—C8—C9—C4	54.5 (6)	C14—C19—C20—C21	173.6 (4)
C10—C8—C9—C4	178.7 (5)	C18—C19—C20—C21	−62.4 (6)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C15—H15B···O4^i	0.99	2.44	3.374 (8)	157
C20—H20···O3^ii	1.00	2.54	3.351 (7)	138

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