(R)-Di-tert-butyl 1,1′-binaphthyl-2,2′-dicarboxyl­ate

Thoss, M.; Seidel, R.W.; Feigel, M.

doi:10.1107/S1600536808044309

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 65| Part 2| February 2009| Page o243

doi:10.1107/S1600536808044309

Open

access

(R)-Di-tert-butyl 1,1′-binaphthyl-2,2′-dicarboxylate

Melanie Thoss,^a Rüdiger W. Seidel ^b and Martin Feigel ^a ^*

^aOrganische Chemie, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany, and ^bAnalytische Chemie, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
^*Correspondence e-mail: feigel@indi-f.nsc.ruhr-uni-bochum.de

(Received 16 December 2008; accepted 31 December 2008; online 8 January 2009)

The crystal structure of the title compound, C₃₀H₃₀O₄, comprises two crystallographically independent half-molecules which are completed by crystallographic twofold symmetry. The dihedral angles between the naphthalene ring planes are 85.83 (3) and 83.69 (3)° for the two molecules. The atoms of the tert-butyl group of one molecule are disordered over two sets of sites with occupancies of 0.60:0.40. The crystal packing is achieved via π–π stacking interactions between the naphthyl groups of adjacent molecules, with a separation of 3.790 (1) Å between the centroids of the rings.

Related literature

For the crystal structure of the parent (R)-2,2′-dihydroxy-1,1′-binaphthyl (BINOL), see: Mori et al. (1993 ). For the synthesis of the corresponding monopivalate of (S)-BINOL, see: Hocke & Uozumi (2002 , 2003 ). For applications of BINOL-derived chiral ligands, see: Shibasaki & Matsunaga (2006 ).

Experimental

Crystal data

C₃₀H₃₀O₄
M_r = 454.54
Orthorhombic, C 222₁
a = 9.6972 (4) Å
b = 25.8488 (13) Å
c = 19.9000 (9) Å
V = 4988.2 (4) Å³
Z = 8
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 108 (2) K
0.37 × 0.21 × 0.18 mm

Data collection

Oxford Diffraction Sapphire2 CCD diffractometer
Absorption correction: multi-scan (ABSPACK in CrysAlis RED; Oxford Diffraction, 2008 $[Oxford Diffraction (2008). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, Oxfordshire, England.]$ ) T_min = 0.972, T_max = 0.984
33031 measured reflections
3175 independent reflections
2423 reflections with I > 2σ(I)
R_int = 0.043

Refinement

R[F² > 2σ(F²)] = 0.033
wR(F²) = 0.072
S = 0.89
3175 reflections
320 parameters
30 restraints
H-atom parameters constrained
Δρ_max = 0.18 e Å⁻³
Δρ_min = −0.16 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2008 $[Oxford Diffraction (2008). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, Oxfordshire, England.]$ ); cell refinement: CrysAlis RED (Oxford Diffraction, 2008 $[Oxford Diffraction (2008). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, Oxfordshire, England.]$ ); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2008 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808044309/dn2418sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808044309/dn2418Isup2.hkl

checkCIF report

Comment top

For the (S)-form of 2,2'-dihydroxy-1,1'-binaphthyl (BINOL) was reported that during the reaction with equimolar amounts of pivaloyl chloride the formation of the corresponding 2,2'-pivalate is almost completely suppressed due to the steric hindrance rising from the bulky pivaloyl group (Hocke & Uozumi, 2002, 2003). However, we obtained the (R)-form of the 2,2'-dipivalate under forced conditions (see below) and determined its structure by X-ray crystallography.

An ORTEP diagram of the title compound is given in Fig. 1. The structure consists of two crystallographic independent molecules, which are located both on crystallographic twofold axes. The molecules belong to the point group C₂ and exhibit axial chirality. Molecular geometry parameters are within expected ranges. The tertiary butyl groups of one molecule show rotational disorder over two sites with occupancies of 0.60:0.40. The dihedral angles between the mean planes of the naphthyl groups are 85.83 (3) and 83.69 (3)° for the non-disordered and the disordered molecule, respectively. In comparison, an angle of 78.35 (5)° has been reported for the parent (R)-BINOL (Mori et al., 1993). The molecules interact via π–π stacking of the naphthyl groups of adjacent molecules with a separation of 3.790 (1) Å between the centroids of the rings C5–C10 and C15–C20. The mean interplanar distance is 3.59 Å and the offset is about 18.9°.

Related literature top

For the crystal structure of the parent (R)-2,2'-dihydroxy-1,1'-binaphthyl (BINOL), see: Mori et al. (1993). For the synthesis of the corresponding monopivalate of (S)-BINOL, see: Hocke & Uozumi (2002, 2003). For applications of BINOL-derived chiral ligands, see: Shibasaki & Matsunaga (2006).

Experimental top

To a solution of (R)-BINOL (4.34 mmol, 1.26 g) and triethylamine (26.7 mmol, 3.7 ml) in acetonitrile (13 ml) was added pivaloyl chloride (8.94 mmol, 1.1 ml) dropwise at 0°C. Subsequent, the reaction mixture was stirred over night and allowed to warm up to room temperature. Diethyl ether was added and the mixture was washed with aqueous 1 N HCl, saturated aqueous NaHCO₃ and brine three times, respectively. The organic phase was dried over MgSO₄ and the solvent was removed under reduced pressure. The crude product was purified by column chromatography over silica gel using ethyl acetate–n-hexane (1:6) as eluent. Yield: 1.15 g (58%). Single crystals of the title compound suitable for X-ray diffraction were grown from ethyl acetate–n-hexane (1:6) by slow evaporation of the solvent.

[α]²⁵_D + 88.94 (c 1.88, THF); ¹H NMR (200 MHz, CDCl₃) δ 7.30–7.37 (m, 4 H), 7.41–7.54 (m, 4 H), 7.96 (d, J = 8.17 Hz, 2 H), 8.01 (d, J = 8.93 Hz, 2 H); ¹³C NMR (200 MHz, CDCl₃) δ 26.33, 38.61, 121.89, 123.62, 125.54, 126.03, 126.56, 127.82, 129.16, 131.44, 133.43, 146.94, 176.31; Anal. calcd for C₃₀H₃₀O₄: C 79.27; H 6.65. Found: C 79.33, H 6.14; MS(FAB): m/z 455.3 [M+H]⁺.

Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2008); cell refinement: CrysAlis RED (Oxford Diffraction, 2008); data reduction: CrysAlis RED (Oxford Diffraction, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

Fig. 1. ORTEP diagram of the title compound. Displacement ellipsoids are drawn at the 50% probability level. H atoms are omitted for clarity. Symmetry codes: (i) -x + 2, y, -z + 1/2, (ii) x, -y + 1, -z + 1.

(R)-Di-tert-butyl 1,1'-binaphthyl-2,2'-dicarboxylate top

Crystal data top

C₃₀H₃₀O₄	F(000) = 1936
M_r = 454.54	D_x = 1.211 Mg m⁻³
Orthorhombic, C222₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: C 2c 2	Cell parameters from 8276 reflections
a = 9.6972 (4) Å	θ = 2.6–30.3°
b = 25.8488 (13) Å	µ = 0.08 mm⁻¹
c = 19.9000 (9) Å	T = 108 K
V = 4988.2 (4) Å³	Prism, colourless
Z = 8	0.37 × 0.21 × 0.18 mm

Data collection top

Oxford Diffraction Sapphire2 CCD diffractometer	3175 independent reflections
Radiation source: Enhance (Mo) X-ray Source	2423 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.043
Detector resolution: 8.4171 pixels mm^-1	θ_max = 27.5°, θ_min = 3.3°
ω scans	h = −12→12
Absorption correction: multi-scan (ABSPACK in CrysAlis RED; Oxford Diffraction, 2008)	k = −31→33
T_min = 0.972, T_max = 0.984	l = −25→25
33031 measured reflections

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)] = 0.033	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.072	H-atom parameters constrained
S = 0.89	w = 1/[σ²(F_o²) + (0.0436P)²] where P = (F_o² + 2F_c²)/3
3175 reflections	(Δ/σ)_max < 0.001
320 parameters	Δρ_max = 0.18 e Å⁻³
30 restraints	Δρ_min = −0.16 e Å⁻³

Crystal data top

C₃₀H₃₀O₄	V = 4988.2 (4) Å³
M_r = 454.54	Z = 8
Orthorhombic, C222₁	Mo Kα radiation
a = 9.6972 (4) Å	µ = 0.08 mm⁻¹
b = 25.8488 (13) Å	T = 108 K
c = 19.9000 (9) Å	0.37 × 0.21 × 0.18 mm

Data collection top

Oxford Diffraction Sapphire2 CCD diffractometer	3175 independent reflections
Absorption correction: multi-scan (ABSPACK in CrysAlis RED; Oxford Diffraction, 2008)	2423 reflections with I > 2σ(I)
T_min = 0.972, T_max = 0.984	R_int = 0.043
33031 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.033	30 restraints
wR(F²) = 0.072	H-atom parameters constrained
S = 0.89	Δρ_max = 0.18 e Å⁻³
3175 reflections	Δρ_min = −0.16 e Å⁻³
320 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	Occ. (<1)
O1	0.63715 (16)	0.30623 (6)	0.17450 (7)	0.0318 (4)
O2	0.82275 (13)	0.26221 (5)	0.21109 (6)	0.0232 (3)
C21	0.7200 (2)	0.27252 (8)	0.16612 (10)	0.0218 (4)
C1	0.94407 (19)	0.32395 (7)	0.27619 (9)	0.0199 (4)
C2	0.8298 (2)	0.29383 (7)	0.26837 (9)	0.0208 (4)
C3	0.7240 (2)	0.29102 (8)	0.31619 (10)	0.0252 (5)
H3	0.6466	0.2692	0.3090	0.030*
C4	0.7338 (2)	0.31991 (8)	0.37300 (10)	0.0260 (5)
H4	0.6630	0.3179	0.4059	0.031*
C5	0.8550 (2)	0.38512 (8)	0.44130 (10)	0.0289 (5)
H5	0.7839	0.3837	0.4741	0.035*
C6	0.9627 (2)	0.41821 (9)	0.45025 (10)	0.0326 (5)
H6	0.9656	0.4400	0.4887	0.039*
C7	1.0696 (2)	0.42013 (9)	0.40251 (11)	0.0321 (5)
H7	1.1449	0.4431	0.4091	0.039*
C8	1.0663 (2)	0.38929 (8)	0.34679 (10)	0.0257 (5)
H8	1.1398	0.3908	0.3153	0.031*
C9	0.9546 (2)	0.35511 (8)	0.33540 (10)	0.0215 (4)
C10	0.8474 (2)	0.35282 (8)	0.38388 (9)	0.0224 (4)
C22	0.7294 (2)	0.23684 (8)	0.10603 (9)	0.0245 (5)
C23	0.7295 (2)	0.18046 (8)	0.13026 (11)	0.0318 (5)
H23A	0.8112	0.1743	0.1581	0.048*
H23B	0.7313	0.1572	0.0913	0.048*
H23C	0.6462	0.1739	0.1568	0.048*
C24	0.8636 (2)	0.24911 (9)	0.06858 (11)	0.0334 (5)
H24A	0.8635	0.2855	0.0548	0.050*
H24B	0.8708	0.2270	0.0287	0.050*
H24C	0.9424	0.2426	0.0983	0.050*
C25	0.6065 (2)	0.24659 (9)	0.06012 (11)	0.0352 (5)
H25A	0.5208	0.2400	0.0848	0.053*
H25B	0.6116	0.2234	0.0212	0.053*
H25C	0.6079	0.2826	0.0448	0.053*
O11	0.49149 (19)	0.36700 (6)	0.55217 (8)	0.0481 (5)
O12	0.35449 (14)	0.43270 (5)	0.52184 (7)	0.0263 (3)
C11	0.53052 (19)	0.48267 (7)	0.46989 (9)	0.0210 (4)
C12	0.4422 (2)	0.44153 (8)	0.46680 (10)	0.0224 (4)
C13	0.4321 (2)	0.40866 (8)	0.41121 (10)	0.0263 (5)
H13	0.3678	0.3809	0.4111	0.032*
C14	0.5153 (2)	0.41686 (8)	0.35726 (10)	0.0270 (5)
H14	0.5077	0.3950	0.3190	0.032*
C15	0.7071 (2)	0.46426 (9)	0.30391 (10)	0.0324 (5)
H15	0.7028	0.4419	0.2660	0.039*
C16	0.8038 (2)	0.50233 (9)	0.30582 (11)	0.0351 (6)
H16	0.8680	0.5058	0.2700	0.042*
C17	0.8088 (2)	0.53657 (9)	0.36088 (11)	0.0344 (5)
H17	0.8754	0.5635	0.3616	0.041*
C18	0.7185 (2)	0.53139 (8)	0.41322 (11)	0.0267 (5)
H18	0.7222	0.5551	0.4496	0.032*
C19	0.6200 (2)	0.49123 (7)	0.41380 (9)	0.0215 (4)
C20	0.6130 (2)	0.45738 (8)	0.35732 (9)	0.0244 (5)
C31	0.3931 (2)	0.39330 (9)	0.56367 (10)	0.0292 (5)
C32	0.2992 (3)	0.38865 (9)	0.62358 (12)	0.0388 (6)
C33	0.3695 (5)	0.3673 (3)	0.6811 (2)	0.0810 (18)	0.601 (3)
H33A	0.3049	0.3646	0.7188	0.122*	0.601 (3)
H33B	0.4464	0.3899	0.6936	0.122*	0.601 (3)
H33C	0.4048	0.3328	0.6699	0.122*	0.601 (3)
C34	0.2190 (6)	0.4386 (2)	0.6369 (3)	0.0647 (13)	0.601 (3)
H34A	0.1620	0.4469	0.5977	0.097*	0.601 (3)
H34B	0.2840	0.4670	0.6452	0.097*	0.601 (3)
H34C	0.1598	0.4340	0.6764	0.097*	0.601 (3)
C35	0.1845 (5)	0.34794 (19)	0.5970 (2)	0.0549 (10)	0.601 (3)
H35A	0.1364	0.3626	0.5581	0.082*	0.601 (3)
H35B	0.1180	0.3410	0.6329	0.082*	0.601 (3)
H35C	0.2299	0.3156	0.5838	0.082*	0.601 (3)
C33'	0.1614 (7)	0.4053 (5)	0.6191 (4)	0.0810 (18)	0.399 (3)
H33D	0.1151	0.3996	0.6622	0.122*	0.399 (3)
H33E	0.1139	0.3858	0.5838	0.122*	0.399 (3)
H33F	0.1593	0.4423	0.6081	0.122*	0.399 (3)
C34'	0.3208 (10)	0.3352 (3)	0.6572 (4)	0.0647 (13)	0.399 (3)
H34D	0.4194	0.3270	0.6582	0.097*	0.399 (3)
H34E	0.2718	0.3086	0.6314	0.097*	0.399 (3)
H34F	0.2848	0.3361	0.7032	0.097*	0.399 (3)
C35'	0.3811 (7)	0.4262 (3)	0.6770 (3)	0.0549 (10)	0.399 (3)
H35D	0.4773	0.4150	0.6807	0.082*	0.399 (3)
H35E	0.3368	0.4239	0.7212	0.082*	0.399 (3)
H35F	0.3779	0.4620	0.6611	0.082*	0.399 (3)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0349 (8)	0.0306 (8)	0.0298 (8)	0.0125 (7)	−0.0038 (7)	−0.0014 (6)
O2	0.0208 (7)	0.0249 (8)	0.0238 (7)	0.0003 (6)	−0.0012 (6)	−0.0050 (6)
C21	0.0191 (10)	0.0226 (11)	0.0238 (10)	−0.0024 (9)	0.0019 (8)	0.0038 (9)
C1	0.0190 (10)	0.0223 (11)	0.0185 (9)	0.0035 (8)	0.0001 (8)	0.0034 (8)
C2	0.0204 (10)	0.0224 (10)	0.0197 (10)	0.0020 (8)	−0.0021 (8)	−0.0008 (8)
C3	0.0206 (10)	0.0265 (12)	0.0284 (11)	−0.0013 (9)	0.0030 (9)	0.0020 (9)
C4	0.0259 (11)	0.0295 (12)	0.0228 (10)	0.0040 (10)	0.0086 (9)	0.0058 (9)
C5	0.0333 (12)	0.0321 (12)	0.0213 (10)	0.0091 (10)	0.0022 (10)	0.0004 (9)
C6	0.0387 (13)	0.0331 (13)	0.0260 (11)	0.0116 (11)	−0.0052 (10)	−0.0085 (10)
C7	0.0274 (11)	0.0322 (13)	0.0368 (12)	0.0021 (10)	−0.0070 (10)	−0.0072 (10)
C8	0.0223 (11)	0.0290 (12)	0.0258 (11)	0.0017 (9)	0.0002 (9)	−0.0009 (9)
C9	0.0218 (10)	0.0225 (11)	0.0201 (10)	0.0040 (8)	−0.0015 (8)	0.0012 (8)
C10	0.0253 (11)	0.0223 (11)	0.0195 (10)	0.0055 (9)	0.0000 (8)	0.0025 (8)
C22	0.0252 (11)	0.0251 (12)	0.0232 (10)	0.0012 (9)	0.0010 (9)	−0.0014 (8)
C23	0.0377 (13)	0.0269 (12)	0.0307 (11)	−0.0019 (10)	0.0000 (10)	−0.0033 (9)
C24	0.0345 (12)	0.0383 (13)	0.0275 (11)	0.0004 (11)	0.0090 (10)	−0.0041 (9)
C25	0.0387 (13)	0.0371 (14)	0.0297 (12)	0.0043 (11)	−0.0083 (10)	−0.0058 (10)
O11	0.0449 (10)	0.0526 (11)	0.0469 (10)	0.0205 (9)	0.0125 (9)	0.0172 (9)
O12	0.0248 (8)	0.0240 (8)	0.0302 (7)	0.0000 (6)	0.0037 (6)	0.0000 (6)
C11	0.0211 (10)	0.0209 (11)	0.0211 (10)	0.0035 (8)	−0.0023 (8)	−0.0003 (8)
C12	0.0194 (10)	0.0217 (11)	0.0260 (11)	0.0037 (8)	0.0002 (9)	0.0017 (8)
C13	0.0256 (11)	0.0216 (11)	0.0319 (11)	−0.0002 (9)	−0.0062 (9)	−0.0026 (9)
C14	0.0311 (12)	0.0272 (12)	0.0227 (10)	0.0051 (10)	−0.0078 (9)	−0.0051 (9)
C15	0.0398 (13)	0.0362 (13)	0.0214 (11)	0.0079 (11)	0.0009 (10)	−0.0022 (10)
C16	0.0327 (12)	0.0445 (14)	0.0282 (12)	0.0059 (11)	0.0101 (10)	0.0055 (10)
C17	0.0314 (12)	0.0330 (13)	0.0388 (13)	−0.0035 (10)	0.0059 (11)	0.0024 (11)
C18	0.0293 (11)	0.0238 (11)	0.0271 (11)	−0.0007 (10)	0.0013 (9)	−0.0010 (9)
C19	0.0227 (10)	0.0218 (11)	0.0201 (10)	0.0044 (9)	−0.0015 (9)	0.0008 (8)
C20	0.0277 (11)	0.0248 (11)	0.0208 (10)	0.0062 (9)	−0.0030 (9)	−0.0001 (9)
C31	0.0285 (12)	0.0292 (12)	0.0298 (11)	−0.0034 (10)	−0.0030 (10)	−0.0011 (10)
C32	0.0392 (13)	0.0397 (14)	0.0377 (12)	−0.0006 (12)	0.0118 (11)	0.0038 (11)
C33	0.045 (2)	0.161 (6)	0.037 (2)	0.008 (3)	0.006 (2)	0.036 (3)
C34	0.072 (3)	0.063 (3)	0.060 (3)	0.002 (2)	0.034 (3)	−0.003 (2)
C35	0.055 (2)	0.062 (3)	0.048 (2)	−0.018 (2)	0.012 (2)	−0.0006 (19)
C33'	0.045 (2)	0.161 (6)	0.037 (2)	0.008 (3)	0.006 (2)	0.036 (3)
C34'	0.072 (3)	0.063 (3)	0.060 (3)	0.002 (2)	0.034 (3)	−0.003 (2)
C35'	0.055 (2)	0.062 (3)	0.048 (2)	−0.018 (2)	0.012 (2)	−0.0006 (19)

Geometric parameters (Å, º) top

O1—C21	1.197 (2)	C12—C13	1.398 (3)
O2—C21	1.365 (2)	C13—C14	1.360 (3)
O2—C2	1.404 (2)	C13—H13	0.9500
C21—C22	1.513 (3)	C14—C20	1.412 (3)
C1—C2	1.363 (3)	C14—H14	0.9500
C1—C9	1.431 (3)	C15—C16	1.360 (3)
C1—C1ⁱ	1.504 (4)	C15—C20	1.412 (3)
C2—C3	1.401 (3)	C15—H15	0.9500
C3—C4	1.358 (3)	C16—C17	1.409 (3)
C3—H3	0.9500	C16—H16	0.9500
C4—C10	1.408 (3)	C17—C18	1.367 (3)
C4—H4	0.9500	C17—H17	0.9500
C5—C6	1.361 (3)	C18—C19	1.411 (3)
C5—C10	1.417 (3)	C18—H18	0.9500
C5—H5	0.9500	C19—C20	1.426 (3)
C6—C7	1.407 (3)	C31—C32	1.505 (3)
C6—H6	0.9500	C32—C33'	1.407 (7)
C7—C8	1.366 (3)	C32—C33	1.441 (5)
C7—H7	0.9500	C32—C34	1.531 (5)
C8—C9	1.417 (3)	C32—C34'	1.549 (7)
C8—H8	0.9500	C32—C35	1.620 (5)
C9—C10	1.419 (3)	C32—C35'	1.644 (6)
C22—C25	1.522 (3)	C33—H33A	0.9800
C22—C24	1.533 (3)	C33—H33B	0.9800
C22—C23	1.535 (3)	C33—H33C	0.9800
C23—H23A	0.9800	C34—H34A	0.9800
C23—H23B	0.9800	C34—H34B	0.9800
C23—H23C	0.9800	C34—H34C	0.9800
C24—H24A	0.9800	C35—H35A	0.9800
C24—H24B	0.9800	C35—H35B	0.9800
C24—H24C	0.9800	C35—H35C	0.9800
C25—H25A	0.9800	C33'—H33D	0.9800
C25—H25B	0.9800	C33'—H33E	0.9800
C25—H25C	0.9800	C33'—H33F	0.9800
O11—C31	1.194 (3)	C34'—H34D	0.9800
O12—C31	1.368 (2)	C34'—H34E	0.9800
O12—C12	1.405 (2)	C34'—H34F	0.9800
C11—C12	1.367 (3)	C35'—H35D	0.9800
C11—C19	1.431 (3)	C35'—H35E	0.9800
C11—C11ⁱⁱ	1.496 (4)	C35'—H35F	0.9800

C21—O2—C2	117.00 (15)	C15—C16—H16	120.0
O1—C21—O2	122.72 (18)	C17—C16—H16	120.0
O1—C21—C22	126.45 (18)	C18—C17—C16	120.6 (2)
O2—C21—C22	110.82 (16)	C18—C17—H17	119.7
C2—C1—C9	118.25 (17)	C16—C17—H17	119.7
C2—C1—C1ⁱ	120.46 (17)	C17—C18—C19	120.8 (2)
C9—C1—C1ⁱ	121.29 (17)	C17—C18—H18	119.6
C1—C2—C3	123.17 (18)	C19—C18—H18	119.6
C1—C2—O2	117.69 (17)	C18—C19—C20	118.49 (18)
C3—C2—O2	119.05 (17)	C18—C19—C11	122.06 (17)
C4—C3—C2	119.06 (19)	C20—C19—C11	119.42 (18)
C4—C3—H3	120.5	C14—C20—C15	121.75 (18)
C2—C3—H3	120.5	C14—C20—C19	119.18 (18)
C3—C4—C10	120.98 (19)	C15—C20—C19	119.03 (19)
C3—C4—H4	119.5	O11—C31—O12	121.7 (2)
C10—C4—H4	119.5	O11—C31—C32	126.1 (2)
C6—C5—C10	121.0 (2)	O12—C31—C32	112.11 (19)
C6—C5—H5	119.5	C33'—C32—C33	128.1 (4)
C10—C5—H5	119.5	C33'—C32—C31	120.0 (4)
C5—C6—C7	119.94 (19)	C33—C32—C31	111.9 (3)
C5—C6—H6	120.0	C33'—C32—C34	43.1 (5)
C7—C6—H6	120.0	C33—C32—C34	115.2 (4)
C8—C7—C6	120.7 (2)	C31—C32—C34	112.2 (3)
C8—C7—H7	119.7	C33'—C32—C34'	115.4 (6)
C6—C7—H7	119.7	C33—C32—C34'	41.6 (4)
C7—C8—C9	120.79 (19)	C31—C32—C34'	109.4 (3)
C7—C8—H8	119.6	C34—C32—C34'	138.3 (4)
C9—C8—H8	119.6	C33'—C32—C35	61.7 (5)
C8—C9—C10	118.51 (17)	C33—C32—C35	109.5 (4)
C8—C9—C1	122.49 (17)	C31—C32—C35	102.0 (2)
C10—C9—C1	118.97 (17)	C34—C32—C35	104.8 (3)
C4—C10—C5	121.36 (19)	C34'—C32—C35	69.8 (4)
C4—C10—C9	119.55 (17)	C33'—C32—C35'	108.6 (6)
C5—C10—C9	119.05 (19)	C33—C32—C35'	59.0 (4)
C21—C22—C25	109.06 (16)	C31—C32—C35'	100.0 (3)
C21—C22—C24	107.99 (16)	C34—C32—C35'	68.6 (4)
C25—C22—C24	109.79 (16)	C34'—C32—C35'	100.5 (5)
C21—C22—C23	109.30 (16)	C35—C32—C35'	157.8 (3)
C25—C22—C23	110.28 (18)	C32—C33—H33A	109.5
C24—C22—C23	110.37 (18)	C32—C33—H33B	109.5
C22—C23—H23A	109.5	H33A—C33—H33B	109.5
C22—C23—H23B	109.5	C32—C33—H33C	109.5
H23A—C23—H23B	109.5	H33A—C33—H33C	109.5
C22—C23—H23C	109.5	H33B—C33—H33C	109.5
H23A—C23—H23C	109.5	C32—C34—H34A	109.5
H23B—C23—H23C	109.5	C32—C34—H34B	109.5
C22—C24—H24A	109.5	H34A—C34—H34B	109.5
C22—C24—H24B	109.5	C32—C34—H34C	109.5
H24A—C24—H24B	109.5	H34A—C34—H34C	109.5
C22—C24—H24C	109.5	H34B—C34—H34C	109.5
H24A—C24—H24C	109.5	C32—C35—H35A	109.5
H24B—C24—H24C	109.5	C32—C35—H35B	109.5
C22—C25—H25A	109.5	H35A—C35—H35B	109.5
C22—C25—H25B	109.5	C32—C35—H35C	109.5
H25A—C25—H25B	109.5	H35A—C35—H35C	109.5
C22—C25—H25C	109.5	H35B—C35—H35C	109.5
H25A—C25—H25C	109.5	C32—C33'—H33D	109.5
H25B—C25—H25C	109.5	C32—C33'—H33E	109.5
C31—O12—C12	115.44 (15)	H33D—C33'—H33E	109.5
C12—C11—C19	117.72 (17)	C32—C33'—H33F	109.5
C12—C11—C11ⁱⁱ	120.13 (17)	H33D—C33'—H33F	109.5
C19—C11—C11ⁱⁱ	122.14 (17)	H33E—C33'—H33F	109.5
C11—C12—C13	123.51 (19)	C32—C34'—H34D	109.5
C11—C12—O12	118.07 (17)	C32—C34'—H34E	109.5
C13—C12—O12	118.40 (18)	H34D—C34'—H34E	109.5
C14—C13—C12	119.23 (19)	C32—C34'—H34F	109.5
C14—C13—H13	120.4	H34D—C34'—H34F	109.5
C12—C13—H13	120.4	H34E—C34'—H34F	109.5
C13—C14—C20	120.87 (18)	C32—C35'—H35D	109.5
C13—C14—H14	119.6	C32—C35'—H35E	109.5
C20—C14—H14	119.6	H35D—C35'—H35E	109.5
C16—C15—C20	121.1 (2)	C32—C35'—H35F	109.5
C16—C15—H15	119.5	H35D—C35'—H35F	109.5
C20—C15—H15	119.5	H35E—C35'—H35F	109.5
C15—C16—C17	120.0 (2)

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

Experimental details

Crystal data
Chemical formula	C₃₀H₃₀O₄
M_r	454.54
Crystal system, space group	Orthorhombic, C222₁
Temperature (K)	108
a, b, c (Å)	9.6972 (4), 25.8488 (13), 19.9000 (9)
V (Å³)	4988.2 (4)
Z	8
Radiation type	Mo Kα
µ (mm⁻¹)	0.08
Crystal size (mm)	0.37 × 0.21 × 0.18

Data collection
Diffractometer	Oxford Diffraction Sapphire2 CCD diffractometer
Absorption correction	Multi-scan (ABSPACK in CrysAlis RED; Oxford Diffraction, 2008)
T_min, T_max	0.972, 0.984
No. of measured, independent and observed [I > 2σ(I)] reflections	33031, 3175, 2423
R_int	0.043
(sin θ/λ)_max (Å⁻¹)	0.650

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.033, 0.072, 0.89
No. of reflections	3175
No. of parameters	320
No. of restraints	30
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.18, −0.16

Computer programs: CrysAlis CCD (Oxford Diffraction, 2008), CrysAlis RED (Oxford Diffraction, 2008), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 2008).

Acknowledgements

The authors thank Dr Christian Gemel for providing diffractometer time. MT thanks the Degussa Foundation and Evonik Industries AG for a PhD fellowship. RWS thanks Professor William S. Sheldrick for generous support.

References

Brandenburg, K. (2008). DIAMOND. Crystal Impact GbR, Bonn, Germany. Google Scholar
Hocke, H. & Uozumi, Y. (2002). Synlett, pp. 2049–2053. Google Scholar
Hocke, H. & Uozumi, Y. (2003). Tetrahedron, 59, 619–630. Web of Science CrossRef CAS Google Scholar
Mori, K., Masuda, Y. & Kashino, S. (1993). Acta Cryst. C49, 1224–1227. CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
Oxford Diffraction (2008). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, Oxfordshire, England. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Shibasaki, M. & Matsunaga, S. (2006). Chem. Soc. Rev. 35, 269–279. Web of Science CrossRef PubMed CAS Google Scholar