Diethyl 2,2-bis­(3,5-di-tert-butyl-4-hy­droxy­benz­yl)malonate

Zeng, T.; Hou, Y.-P.; Ren, W.-Z.; Xu, W.-Y.

doi:10.1107/S1600536811054900

organic compounds

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ISSN: 2056-9890

Volume 68| Part 2| February 2012| Page o448

doi:10.1107/S1600536811054900

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Diethyl 2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonate

Tao Zeng,^a ^* Yu-Ping Hou,^b Wan-Zhong Ren ^a and Wen-You Xu ^a

^aChemistry & Biology College, Yantai University, Yantai 264005, People's Republic of China, and ^bYantai University, Yantai 264005, People's Republic of China
^*Correspondence e-mail: zengtaotj@126.com

(Received 11 December 2011; accepted 20 December 2011; online 18 January 2012)

The title molecule, C₃₇H₅₆O₆, possesses twofold symmetry, with the twofold axis passing through the quaternary C atom. In the crystal, neighbouring molecules are linked via O—H⋯O hydrogen bonds involving the phenol OH group and the carbonyl O atom, forming chains propagating in [101]. Within these chains, rings are formed with an R₂²(20) motif. There are also C—H⋯O interactions present within the rings.

Related literature

For hindered phenol antioxidants and their applications, see: Eggensperger et al. (1974 , 1976 ); Breese et al. 2000 ; Yamazaki & Seguchi (1997 ). For the synthesis of hindered phenol antioxidants, see: Eggensperger et al. (1974, 1976). For hydrogen-bond motifs, see: Bernstein et al. (1995 ).

Experimental

Crystal data

C₃₇H₅₆O₆
M_r = 596.82
Monoclinic, C 2/c
a = 20.006 (6) Å
b = 13.610 (4) Å
c = 14.252 (4) Å
β = 111.344 (5)°
V = 3614.4 (18) Å³
Z = 4
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 294 K
0.22 × 0.18 × 0.16 mm

Data collection

Bruker SMART 1000 diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ) T_min = 0.984, T_max = 0.989
9457 measured reflections
3280 independent reflections
2010 reflections with I > 2σ(I)
R_int = 0.042

Refinement

R[F² > 2σ(F²)] = 0.053
wR(F²) = 0.151
S = 1.06
3280 reflections
206 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.34 e Å⁻³
Δρ_min = −0.25 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯O2ⁱ	0.80 (2)	2.38 (2)	2.996 (2)	134 (2)
C12—H12C⋯O2ⁱ	0.96	2.46	3.398 (3)	167
Symmetry code: (i) $[-x+{\script{3\over 2}}, -y+{\script{1\over 2}}, -z+1]$ .

Data collection: SMART (Bruker, 1997 ); cell refinement: SAINT (Bruker, 1997); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009 ) and Mercury (Macrae et al., 2008 ); software used to prepare material for publication: SHELXL97 and publCIF (Westrip, 2010 ).

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811054900/fb2240sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811054900/fb2240Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536811054900/fb2240Isup3.cml

checkCIF report

Comment top

A series of compounds containing the 2,6-di-tert-butylphenol moiety have been used in both polymers and lubricants as antioxidants (Eggensperger et al., 1974, 1976). They are often called hindered phenol antioxidants due to the presence of the extremely large 2,6-di-tert-butylphenol moiety (Breese et al., 2000; Yamazaki & Seguchi, 1997). As part of our ongoing studies of the chemistry of such compounds, we present herein the synthesis and the crystal structure of the title compound.

The title molecule is located about a 2-fold axis (Fig. 1), which passes through the quaternary carbon atom, C16. The bond angles involving C16 vary from 106.2 (2) to 111.9 (2)°. The remainder of the geometric parameters are within normal ranges.

In the crystal, neighbouring molecules are linked by O—H···O hydrogen bonds (Tab. 1 and Fig. 2), involving the phenolic OH group and the carbonyl O atom, forming chains in direction [1 0 1] that contain rings with a R²₂(20) motif (Bernstein et al., 1995). These rings are situated about the i nversion centres (the Wyckoff position 4c). C-H···O interactions are also present within the rings (Tab. 1).

Related literature top

For hindered phenol antioxidants and their applications, see: Eggensperger et al. (1974, 1976); Breese et al. 2000; Yamazaki & Seguchi (1997). For the synthesis of hindered phenol antioxidants, see: Eggensperger et al. (1974, 1976). For hydrogen-bond motifs, see: Bernstein et al. (1995).

Experimental top

A mixture of diethyl malonate (4.0 g, 0.025 mol) and 2,6-di-tert-butyl-4-((dimethylamino)methyl)phenol (13.2 g, 0.05 mol) in 80 ml of toluene was heated to 373 K under a nitrogen atmosphere. Lithium amide (0.2 g) was then added and the mixture was stirred for further 6 h. The reaction mixture was then diluted with toluene (60 ml), washed with water (40 ml), and the oil layer was separated and dried with anhydrous MgSO₄. After filtration and concentration, the solution was allowed to evaporate in the air to give the title product as a white powder [yield 13.1 g; 87.9%]. Block-like colourless crystals with dimensions at about 2-3 mm were obtained by slow evaporation of the solution of the title compound in toluene/ethanol (3:1; v:v).

Computing details top

Data collection: SMART (Bruker, 1997); cell refinement: SAINT (Bruker, 1997); data reduction: SAINT (Bruker, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009) and Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and publCIF (Westrip, 2010).

Figures top

	Fig. 1. A view of the molecular structure of the title molecule, with the atomic numbering scheme and displacement ellipsoids drawn at the 50% probability level. The 2-fold axis bisects atom C16 [symmetry code: (a) -x+1, y, -z+1/2].
	Fig. 2. The crystal packing of the title compound, viewed along the b axis, showing the O—H···O hydrogen bonds and as dashed cyan lines [C-bound H atoms have been omitted for clarity; see Tab. 1 for details].

Diethyl 2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonate top

Crystal data top

C₃₇H₅₆O₆	F(000) = 1304
M_r = 596.82	D_x = 1.097 Mg m⁻³
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 2211 reflections
a = 20.006 (6) Å	θ = 2.2–23.3°
b = 13.610 (4) Å	µ = 0.07 mm⁻¹
c = 14.252 (4) Å	T = 294 K
β = 111.344 (5)°	Block, colourless
V = 3614.4 (18) Å³	0.22 × 0.18 × 0.16 mm
Z = 4

Data collection top

Bruker SMART 1000 diffractometer	3280 independent reflections
Radiation source: fine-focus sealed tube	2010 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.042
ϕ and ω scans	θ_max = 25.3°, θ_min = 1.9°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −24→20
T_min = 0.984, T_max = 0.989	k = −16→11
9457 measured reflections	l = −14→17

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F² > 2σ(F²)] = 0.053	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.151	w = 1/[σ²(F_o²) + (0.0716P)² + 0.7136P] where P = (F_o² + 2F_c²)/3
S = 1.06	(Δ/σ)_max < 0.001
3280 reflections	Δρ_max = 0.34 e Å⁻³
206 parameters	Δρ_min = −0.25 e Å⁻³
1 restraint	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
102 constraints	Extinction coefficient: 0.009 (1)
Primary atom site location: structure-invariant direct methods

Crystal data top

C₃₇H₅₆O₆	V = 3614.4 (18) Å³
M_r = 596.82	Z = 4
Monoclinic, C2/c	Mo Kα radiation
a = 20.006 (6) Å	µ = 0.07 mm⁻¹
b = 13.610 (4) Å	T = 294 K
c = 14.252 (4) Å	0.22 × 0.18 × 0.16 mm
β = 111.344 (5)°

Data collection top

Bruker SMART 1000 diffractometer	3280 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	2010 reflections with I > 2σ(I)
T_min = 0.984, T_max = 0.989	R_int = 0.042
9457 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.053	1 restraint
wR(F²) = 0.151	H atoms treated by a mixture of independent and constrained refinement
S = 1.06	Δρ_max = 0.34 e Å⁻³
3280 reflections	Δρ_min = −0.25 e Å⁻³
206 parameters

Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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
O1	0.71866 (9)	0.42187 (11)	0.62113 (12)	0.0666 (5)
H1	0.7512 (12)	0.3850 (16)	0.6488 (18)	0.080*
O2	0.62147 (8)	0.10154 (10)	0.29387 (12)	0.0648 (5)
O3	0.54675 (8)	0.02822 (10)	0.35618 (12)	0.0569 (5)
C1	0.66141 (11)	0.37176 (15)	0.55316 (15)	0.0447 (5)
C2	0.64934 (10)	0.27165 (15)	0.56606 (14)	0.0427 (5)
C3	0.59129 (11)	0.22877 (15)	0.49092 (14)	0.0442 (5)
H3A	0.5820	0.1627	0.4976	0.053*
C4	0.54664 (10)	0.27825 (14)	0.40700 (14)	0.0410 (5)
C5	0.55917 (10)	0.37794 (14)	0.40102 (15)	0.0442 (5)
H5A	0.5288	0.4130	0.3460	0.053*
C6	0.61499 (11)	0.42780 (14)	0.47341 (14)	0.0433 (5)
C7	0.62391 (12)	0.54031 (16)	0.46818 (17)	0.0563 (6)
C8	0.69596 (16)	0.56725 (19)	0.4609 (2)	0.0836 (9)
H8A	0.6997	0.6374	0.4579	0.125*
H8B	0.6992	0.5386	0.4011	0.125*
H8C	0.7342	0.5427	0.5189	0.125*
C9	0.56543 (16)	0.58469 (17)	0.3764 (2)	0.0934 (10)
H9A	0.5193	0.5717	0.3801	0.140*
H9B	0.5677	0.5559	0.3162	0.140*
H9C	0.5725	0.6544	0.3753	0.140*
C10	0.61797 (15)	0.58785 (18)	0.5627 (2)	0.0780 (8)
H10A	0.5727	0.5708	0.5673	0.117*
H10B	0.6213	0.6580	0.5584	0.117*
H10C	0.6562	0.5645	0.6215	0.117*
C11	0.69699 (12)	0.21224 (15)	0.65805 (15)	0.0509 (6)
C12	0.77149 (12)	0.19636 (19)	0.6533 (2)	0.0744 (8)
H12A	0.7666	0.1663	0.5902	0.112*
H12B	0.7992	0.1543	0.7076	0.112*
H12C	0.7953	0.2585	0.6590	0.112*
C13	0.66642 (15)	0.10925 (19)	0.6605 (2)	0.0815 (9)
H13A	0.6176	0.1147	0.6563	0.122*
H13B	0.6944	0.0771	0.7223	0.122*
H13C	0.6682	0.0716	0.6046	0.122*
C14	0.7024 (2)	0.2628 (2)	0.75627 (18)	0.1034 (11)
H14A	0.7281	0.3236	0.7627	0.155*
H14B	0.7276	0.2208	0.8121	0.155*
H14C	0.6551	0.2757	0.7557	0.155*
C15	0.48315 (10)	0.22752 (14)	0.32896 (15)	0.0432 (5)
H15A	0.4486	0.2774	0.2933	0.052*
H15B	0.4604	0.1860	0.3639	0.052*
C16	0.5000	0.16358 (19)	0.2500	0.0390 (7)
C17	0.56390 (11)	0.09625 (14)	0.30121 (16)	0.0452 (5)
C18	0.60223 (15)	−0.04431 (19)	0.4048 (2)	0.0806 (9)
H18A	0.6138	−0.0811	0.3544	0.097*
H18B	0.6454	−0.0117	0.4487	0.097*
C19	0.5756 (2)	−0.1098 (2)	0.4627 (3)	0.1349 (15)
H19A	0.5583	−0.0721	0.5061	0.202*
H19B	0.6136	−0.1522	0.5027	0.202*
H19C	0.5372	−0.1487	0.4179	0.202*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0501 (10)	0.0581 (10)	0.0683 (11)	0.0038 (8)	−0.0064 (8)	−0.0100 (8)
O2	0.0362 (9)	0.0680 (11)	0.0886 (12)	0.0093 (7)	0.0209 (8)	0.0083 (9)
O3	0.0506 (9)	0.0445 (9)	0.0687 (10)	0.0078 (7)	0.0133 (8)	0.0154 (8)
C1	0.0392 (12)	0.0532 (13)	0.0402 (12)	0.0006 (10)	0.0125 (10)	−0.0089 (10)
C2	0.0412 (12)	0.0520 (13)	0.0357 (11)	0.0039 (10)	0.0150 (10)	−0.0004 (10)
C3	0.0450 (12)	0.0457 (12)	0.0434 (12)	0.0003 (9)	0.0179 (10)	0.0027 (10)
C4	0.0370 (11)	0.0462 (12)	0.0406 (11)	0.0020 (9)	0.0149 (9)	−0.0023 (9)
C5	0.0405 (12)	0.0485 (13)	0.0403 (11)	0.0072 (9)	0.0107 (10)	0.0008 (10)
C6	0.0426 (12)	0.0442 (12)	0.0424 (12)	0.0030 (9)	0.0146 (10)	−0.0024 (10)
C7	0.0490 (14)	0.0466 (13)	0.0623 (15)	0.0011 (10)	0.0071 (12)	−0.0023 (11)
C8	0.081 (2)	0.0697 (17)	0.105 (2)	−0.0119 (14)	0.0392 (17)	0.0075 (16)
C9	0.098 (2)	0.0500 (15)	0.091 (2)	−0.0007 (14)	−0.0152 (17)	0.0087 (14)
C10	0.083 (2)	0.0578 (16)	0.0886 (19)	0.0071 (13)	0.0263 (16)	−0.0202 (14)
C11	0.0536 (14)	0.0575 (14)	0.0390 (12)	0.0061 (10)	0.0137 (10)	0.0040 (10)
C12	0.0547 (16)	0.0748 (17)	0.0890 (19)	0.0154 (12)	0.0204 (14)	0.0210 (15)
C13	0.0780 (19)	0.0861 (19)	0.0679 (17)	−0.0075 (15)	0.0115 (14)	0.0331 (15)
C14	0.146 (3)	0.114 (2)	0.0415 (15)	0.039 (2)	0.0247 (17)	0.0077 (15)
C15	0.0357 (11)	0.0466 (12)	0.0462 (12)	0.0021 (9)	0.0135 (9)	0.0023 (10)
C16	0.0318 (15)	0.0369 (15)	0.0434 (16)	0.000	0.0079 (13)	0.000
C17	0.0389 (13)	0.0398 (12)	0.0529 (13)	−0.0006 (9)	0.0118 (10)	−0.0039 (10)
C18	0.080 (2)	0.0642 (17)	0.088 (2)	0.0283 (14)	0.0186 (16)	0.0248 (15)
C19	0.120 (3)	0.099 (2)	0.193 (4)	0.031 (2)	0.066 (3)	0.083 (3)

Geometric parameters (Å, º) top

O1—C1	1.381 (2)	C10—H10B	0.9600
O1—H1	0.803 (16)	C10—H10C	0.9600
O2—C17	1.196 (2)	C11—C14	1.528 (3)
O3—C17	1.336 (2)	C11—C12	1.532 (3)
O3—C18	1.459 (3)	C11—C13	1.535 (3)
C1—C6	1.403 (3)	C12—H12A	0.9600
C1—C2	1.407 (3)	C12—H12B	0.9600
C2—C3	1.389 (3)	C12—H12C	0.9600
C2—C11	1.540 (3)	C13—H13A	0.9600
C3—C4	1.380 (3)	C13—H13B	0.9600
C3—H3A	0.9300	C13—H13C	0.9600
C4—C5	1.388 (3)	C14—H14A	0.9600
C4—C15	1.516 (3)	C14—H14B	0.9600
C5—C6	1.390 (3)	C14—H14C	0.9600
C5—H5A	0.9300	C15—C16	1.554 (2)
C6—C7	1.547 (3)	C15—H15A	0.9700
C7—C9	1.526 (3)	C15—H15B	0.9700
C7—C8	1.527 (4)	C16—C17ⁱ	1.526 (2)
C7—C10	1.538 (3)	C16—C17	1.526 (2)
C8—H8A	0.9600	C16—C15ⁱ	1.554 (2)
C8—H8B	0.9600	C18—C19	1.442 (4)
C8—H8C	0.9600	C18—H18A	0.9700
C9—H9A	0.9600	C18—H18B	0.9700
C9—H9B	0.9600	C19—H19A	0.9600
C9—H9C	0.9600	C19—H19B	0.9600
C10—H10A	0.9600	C19—H19C	0.9600

C1—O1—H1	110.7 (19)	C12—C11—C2	110.30 (17)
C17—O3—C18	115.76 (19)	C13—C11—C2	111.76 (18)
O1—C1—C6	115.80 (19)	C11—C12—H12A	109.5
O1—C1—C2	121.62 (18)	C11—C12—H12B	109.5
C6—C1—C2	122.53 (18)	H12A—C12—H12B	109.5
C3—C2—C1	116.16 (18)	C11—C12—H12C	109.5
C3—C2—C11	121.36 (18)	H12A—C12—H12C	109.5
C1—C2—C11	122.48 (18)	H12B—C12—H12C	109.5
C4—C3—C2	123.98 (19)	C11—C13—H13A	109.5
C4—C3—H3A	118.0	C11—C13—H13B	109.5
C2—C3—H3A	118.0	H13A—C13—H13B	109.5
C3—C4—C5	117.11 (18)	C11—C13—H13C	109.5
C3—C4—C15	121.26 (18)	H13A—C13—H13C	109.5
C5—C4—C15	121.46 (17)	H13B—C13—H13C	109.5
C4—C5—C6	123.08 (18)	C11—C14—H14A	109.5
C4—C5—H5A	118.5	C11—C14—H14B	109.5
C6—C5—H5A	118.5	H14A—C14—H14B	109.5
C5—C6—C1	116.87 (19)	C11—C14—H14C	109.5
C5—C6—C7	121.54 (17)	H14A—C14—H14C	109.5
C1—C6—C7	121.56 (18)	H14B—C14—H14C	109.5
C9—C7—C8	107.1 (2)	C4—C15—C16	116.22 (15)
C9—C7—C10	107.7 (2)	C4—C15—H15A	108.2
C8—C7—C10	109.6 (2)	C16—C15—H15A	108.2
C9—C7—C6	111.54 (18)	C4—C15—H15B	108.2
C8—C7—C6	111.67 (18)	C16—C15—H15B	108.2
C10—C7—C6	109.11 (19)	H15A—C15—H15B	107.4
C7—C8—H8A	109.5	C17ⁱ—C16—C17	106.2 (2)
C7—C8—H8B	109.5	C17ⁱ—C16—C15ⁱ	110.79 (10)
H8A—C8—H8B	109.5	C17—C16—C15ⁱ	108.55 (11)
C7—C8—H8C	109.5	C17ⁱ—C16—C15	108.55 (11)
H8A—C8—H8C	109.5	C17—C16—C15	110.79 (10)
H8B—C8—H8C	109.5	C15ⁱ—C16—C15	111.9 (2)
C7—C9—H9A	109.5	O2—C17—O3	123.65 (19)
C7—C9—H9B	109.5	O2—C17—C16	126.01 (18)
H9A—C9—H9B	109.5	O3—C17—C16	110.34 (17)
C7—C9—H9C	109.5	C19—C18—O3	108.3 (3)
H9A—C9—H9C	109.5	C19—C18—H18A	110.0
H9B—C9—H9C	109.5	O3—C18—H18A	110.0
C7—C10—H10A	109.5	C19—C18—H18B	110.0
C7—C10—H10B	109.5	O3—C18—H18B	110.0
H10A—C10—H10B	109.5	H18A—C18—H18B	108.4
C7—C10—H10C	109.5	C18—C19—H19A	109.5
H10A—C10—H10C	109.5	C18—C19—H19B	109.5
H10B—C10—H10C	109.5	H19A—C19—H19B	109.5
C14—C11—C12	111.0 (2)	C18—C19—H19C	109.5
C14—C11—C13	106.6 (2)	H19A—C19—H19C	109.5
C12—C11—C13	105.9 (2)	H19B—C19—H19C	109.5
C14—C11—C2	111.06 (18)

O1—C1—C2—C3	−178.03 (19)	C1—C6—C7—C10	−59.1 (3)
C6—C1—C2—C3	4.5 (3)	C3—C2—C11—C14	−126.1 (3)
O1—C1—C2—C11	2.3 (3)	C1—C2—C11—C14	53.5 (3)
C6—C1—C2—C11	−175.11 (18)	C3—C2—C11—C12	110.4 (2)
C1—C2—C3—C4	0.2 (3)	C1—C2—C11—C12	−69.9 (3)
C11—C2—C3—C4	179.83 (18)	C3—C2—C11—C13	−7.1 (3)
C2—C3—C4—C5	−3.3 (3)	C1—C2—C11—C13	172.5 (2)
C2—C3—C4—C15	−178.59 (19)	C3—C4—C15—C16	−81.2 (2)
C3—C4—C5—C6	1.8 (3)	C5—C4—C15—C16	103.7 (2)
C15—C4—C5—C6	177.16 (19)	C4—C15—C16—C17ⁱ	163.70 (16)
C4—C5—C6—C1	2.5 (3)	C4—C15—C16—C17	47.5 (2)
C4—C5—C6—C7	−175.45 (19)	C4—C15—C16—C15ⁱ	−73.76 (15)
O1—C1—C6—C5	176.62 (18)	C18—O3—C17—O2	−2.7 (3)
C2—C1—C6—C5	−5.8 (3)	C18—O3—C17—C16	176.81 (18)
O1—C1—C6—C7	−5.4 (3)	C17ⁱ—C16—C17—O2	129.7 (2)
C2—C1—C6—C7	172.14 (19)	C15ⁱ—C16—C17—O2	10.6 (3)
C5—C6—C7—C9	−0.2 (3)	C15—C16—C17—O2	−112.6 (2)
C1—C6—C7—C9	−178.0 (2)	C17ⁱ—C16—C17—O3	−49.75 (12)
C5—C6—C7—C8	−120.0 (2)	C15ⁱ—C16—C17—O3	−168.89 (16)
C1—C6—C7—C8	62.1 (3)	C15—C16—C17—O3	67.9 (2)
C5—C6—C7—C10	118.7 (2)	C17—O3—C18—C19	178.4 (3)

Symmetry code: (i) −x+1, y, −z+1/2.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O2ⁱⁱ	0.80 (2)	2.38 (2)	2.996 (2)	134 (2)
C12—H12C···O2ⁱⁱ	0.96	2.46	3.398 (3)	167

Symmetry code: (ii) −x+3/2, −y+1/2, −z+1.

Experimental details

Crystal data
Chemical formula	C₃₇H₅₆O₆
M_r	596.82
Crystal system, space group	Monoclinic, C2/c
Temperature (K)	294
a, b, c (Å)	20.006 (6), 13.610 (4), 14.252 (4)
β (°)	111.344 (5)
V (Å³)	3614.4 (18)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.07
Crystal size (mm)	0.22 × 0.18 × 0.16

Data collection
Diffractometer	Bruker SMART 1000 diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 1996)
T_min, T_max	0.984, 0.989
No. of measured, independent and observed [I > 2σ(I)] reflections	9457, 3280, 2010
R_int	0.042
(sin θ/λ)_max (Å⁻¹)	0.600

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.053, 0.151, 1.06
No. of reflections	3280
No. of parameters	206
No. of restraints	1
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.34, −0.25

Computer programs: SMART (Bruker, 1997), SAINT (Bruker, 1997), SHELXS97 (Sheldrick, 2008), PLATON (Spek, 2009) and Mercury (Macrae et al., 2008), SHELXL97 (Sheldrick, 2008) and publCIF (Westrip, 2010).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O2ⁱ	0.803 (16)	2.38 (2)	2.996 (2)	134 (2)
C12—H12C···O2ⁱ	0.96	2.46	3.398 (3)	167

Symmetry code: (i) −x+3/2, −y+1/2, −z+1.

Acknowledgements

The authors gratefully acknowledge financial support from the Technology Development Project of Shandong Province (No. 2010GGX10316) and the University Science and Technology Project of Shandong Province Education Committee (No. J09LB56).

References

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