7-(tert-Butyl­diphenyl­sil­yloxy)-2,2-dimethyl-1-benzofuran-3(2H)-one

Salas, C.O.; Tapia, R.A.; Macías, A.

doi:10.1107/S1600536810054462

organic compounds

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ISSN: 2056-9890

Volume 67| Part 2| February 2011| Page o375

doi:10.1107/S1600536810054462

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7-(tert-Butyldiphenylsilyloxy)-2,2-dimethyl-1-benzofuran-3(2H)-one

Cristian O. Salas,^a ^* Ricardo A. Tapia ^a and Alejandro Macías ^b

^aDepartamento de Química Orgánica, Facultad de Química, Pontificia Universidad Católica de Chile, 702843 Santiago de Chile, Chile, and ^bDepartamento de Química Inorgánica, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
^*Correspondence e-mail: cosalas@puc.cl

(Received 15 December 2010; accepted 27 December 2010; online 12 January 2011)

The title compound, C₂₆H₂₈O₃Si, is an allylic oxidation product of the tert-butyl(2,2-dimethyl-2,3-dihydrobenzofuran-7-yloxy)diphenylsilane with N-bromosuccinimide and 2,2′-azobis-isobutyronitrile. The nine-atom bicyclic system is almost planar, with an r.m.s deviation of 0.0123 (2) Å and a maximum deviation of 0.031 (2) Å for the O atom. In the crystal, the molecules pile up along the b axis but the strongest intermolecular contacts are the π–π stacking interactions between the benzene rings along the c axis [centroid–centroid distance = 3.655 (3) Å].

Related literature

Benzofuranones are precursors of a wide range of natural and synthetic products. For a related transformation of benzofuranones in aurones, see: Schoepfer et al. (2002 ); Löser et al. (2004 ); in spiroannulated and aromatic spiroketal compounds, see: Braun et al. (2008 ); Zhou et al. (2008 ); in benzofurane derivatives, see: Venkatesan et al.(2010 ); and in pyranobenzofuranes, see: Foroumadi et al. (2009 ).

Experimental

Crystal data

C₂₆H₂₈O₃Si
M_r = 416.57
Triclinic, $[P \overline 1]$
a = 9.8210 (18) Å
b = 11.081 (2) Å
c = 12.025 (2) Å
α = 98.803 (2)°
β = 112.151 (2)°
γ = 101.791 (2)°
V = 1147.7 (4) Å³
Z = 2
Mo Kα radiation
μ = 0.13 mm⁻¹
T = 100 K
0.49 × 0.43 × 0.10 mm

Data collection

Bruker SMART 1000 CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2001 ) T_min = 0.941, T_max = 0.988
14369 measured reflections
4197 independent reflections
3325 reflections with I > 2σ(I)
R_int = 0.032

Refinement

R[F² > 2σ(F²)] = 0.044
wR(F²) = 0.111
S = 1.05
4197 reflections
276 parameters
H-atom parameters constrained
Δρ_max = 0.83 e Å⁻³
Δρ_min = −0.29 e Å⁻³

Data collection: SMART (Bruker, 2007 ); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT; program(s) used to solve structure: SIR97 (Altomare et al., 1999 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ); software used to prepare material for publication: WinGX (Farrugia, 1999 ).

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810054462/si2320sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536810054462/si2320Isup2.hkl

checkCIF report

Comment top

Benzofuranones are very important compounds because of their use in a wide range of natural and synthetic products with relevant properties such as spiroannulated benzofuranones (Braun et al., 2008), aromatics spiroketals compounds (Zhou et al., 2008), aurones (Schoepfer et al, 2002; Löser et al., 2004), pyranobenzofuranes (Foroumadi et al., 2009) and some benzofuranes derivatives (Venkatesan et al., 2010). The benzofuranone 3 is the product of the allylic oxidation of the tert-butyl-(2,2-dimethyl-2,3-dihydrobenzofuran-7-yloxy)diphenylsilane with N-bromosuccinimide (NBS) and 2,2'-azobis-isobutyronitrile (AIBN) (Fig. 2). The molecular structure of the title compound is represented in Fig. 1. Bond lengths and angles are within the expected values and confirm the bond orders giving in the Scheme. The 9-atom bicyclic system is, as expected, planar, with r.m.s deviation = 0.0123 (2) Å and a maximum deviation of 0.031 (2) Å. The molecules pile up along the b axis but the strongest intermolecular contacts are the π–π stacking interactions between the benzo rings along the c axis [centroid–centroid distances = 3.655 (5) Å].

Related literature top

Benzofuranones are precursors of a wide range of natural and synthetic products. For a related transformation of benzofuranones in aurones, see: Schoepfer et al. (2002); Löser et al. (2004); in spiroannulated and aromatic spiroketal compounds, see: Braun et al. (2008); Zhou et al. (2008); in benzofurane derivatives, see: Venkatesan et al.(2010); and in pyranobenzofuranes, see: Foroumadi et al. (2009).

Experimental top

tert-Butyl-(2,2-dimethyl-2,3-dihydrobenzofuran-7-yloxy)diphenylsilane (2)

tert-Butyldiphenylsilyl chloride (1.0 g, 3.64 mmol) and imidazole (1.52 g, 22.35 mmol) were added to a solution of 2,2-dimethyl-2,3-dihydrobenzofuran-7-ol (1) (0.59 g, 3.62 mmol) in dry THF (50 ml) and the mixture was stirred at room temperature for 12 h. under an nitrogen atmosphere. Petroleum ether (100 ml) was added and the solid was filtered off and the solvents were removed in vacuo to give an oil residue, which was purified by flash column chromatography (CH₂Cl₂/ petroleum ether, 9:1) to give tert-butyl-(2,2-dimethyl-2,3-dihydrobenzofuran-7-yloxy)diphenylsilane (2) (1.43 g, 98%) as a colorless oil.

7-(tert-Butyldiphenylsilyloxy)-2,2-dimethylbenzofuran-3(2H)-one (3).

NBS (1.54 g, 8.70 mmol) and AIBN (25 mg) were added to a solution of tert-butyl(2,2-dimethyl-2,3-dihydrobenzofuran-7-yloxy)diphenylsilane (2) (1.0 g, 2.39 mmol) in dry CCl₄ (150 ml) and the resulting suspension was stirred at reflux for 2 h. The mixture was cooled and filtered. The filtrate was evaporated to dryness in vacuo to give a residue, which was purified by flash column chromatography (CH₂Cl₂) to give 7-(tert-butyldiphenylsilyloxy)-2,2-dimethylbenzofuran-3(2H)-one (3) (0.75 g, 75%) as a white solid. mp: 354.5–355.5 K. Crystals were grown by slow evaporation from CH₂Cl₂.

Computing details top

Data collection: SMART (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top

	Fig. 1. The structure of the title compound, with displacement ellipsoids drawn at the 50% probability level and H atoms with arbitrary radius.
	Fig. 2. Chemical reactions scheme for obtain molecule 3.

7-(tert-Butyldiphenylsilyloxy)-2,2-dimethyl-1-benzofuran-3(2H)-one top

Crystal data top

C₂₆H₂₈O₃Si	Z = 2
M_r = 416.57	F(000) = 444
Triclinic, P1	D_x = 1.205 Mg m⁻³
a = 9.8210 (18) Å	Mo Kα radiation, λ = 0.71073 Å
b = 11.081 (2) Å	Cell parameters from 3414 reflections
c = 12.025 (2) Å	θ = 2.3–27.3°
α = 98.803 (2)°	µ = 0.13 mm⁻¹
β = 112.151 (2)°	T = 100 K
γ = 101.791 (2)°	Prism, colourless
V = 1147.7 (4) Å³	0.49 × 0.43 × 0.10 mm

Data collection top

Bruker SMART 1000 CCD diffractometer	4197 independent reflections
Radiation source: fine-focus sealed tube	3325 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.032
ω scans	θ_max = 25.4°, θ_min = 1.9°
Absorption correction: multi-scan (SADABS; Bruker, 2001)	h = −11→10
T_min = 0.941, T_max = 0.988	k = −13→13
14369 measured reflections	l = 0→14

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)] = 0.044	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.111	H-atom parameters constrained
S = 1.05	w = 1/[σ²(F_o²) + (0.0422P)² + 0.8404P] where P = (F_o² + 2F_c²)/3
4197 reflections	(Δ/σ)_max < 0.001
276 parameters	Δρ_max = 0.83 e Å⁻³
0 restraints	Δρ_min = −0.29 e Å⁻³

Crystal data top

C₂₆H₂₈O₃Si	γ = 101.791 (2)°
M_r = 416.57	V = 1147.7 (4) Å³
Triclinic, P1	Z = 2
a = 9.8210 (18) Å	Mo Kα radiation
b = 11.081 (2) Å	µ = 0.13 mm⁻¹
c = 12.025 (2) Å	T = 100 K
α = 98.803 (2)°	0.49 × 0.43 × 0.10 mm
β = 112.151 (2)°

Data collection top

Bruker SMART 1000 CCD diffractometer	4197 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2001)	3325 reflections with I > 2σ(I)
T_min = 0.941, T_max = 0.988	R_int = 0.032
14369 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.044	0 restraints
wR(F²) = 0.111	H-atom parameters constrained
S = 1.05	Δρ_max = 0.83 e Å⁻³
4197 reflections	Δρ_min = −0.29 e Å⁻³
276 parameters

Special details top

Experimental. tert-Butyl-(2,2-dimethyl-2,3-dihydrobenzofuran-7-yloxy)diphenylsilane (2)

¹H RMN (CDCl₃, 200 MHz) d 1.18 (s, 9H, 3xCH₃); 1.34 (s, 6H, 2xCH₃), 2.96 (s, 2H, H3); 6.53–6.56 (m, 2H, H5, H4); 6.70 (m, 1H, H6); 7.35–7.44 (m, 6H, H—Ar); 7.38–7.83 (m, 4H, H—Ar). ¹³C RMN (CDCl₃, 50 MHz) d 19.7 (C(CH₃)₃); 26.8 (3xCH₃); 28.1 (2xCH₃); 43.4 (C3); 86.4 (C2); 117.9 (C6); 119.6 (C5); 119.8 (C4); 127.5 (Ar); 127.8 (C3a); 129.6 (Ar); 133.9 (Ar); 135.7 (Ar); 139.9 (C7); 149.4 (C7a).

7-(tert-Butyldiphenylsilyloxy)-2,2-dimethylbenzofuran-3(2H)-one (3).

IR (NaCl, cm^-1): 1714 (CO). ¹H-RMN (CDCl₃, 200 MHz) d 1.18 (s, 9H, 3xCH₃); 1.30 (s, 6H, 2xCH₃); 6.74 (t, 1H, J =7.7 Hz, H5,); 6.97 (dd, 1H, J =1.1, J =7.8 Hz, H6); 7.21 (dd, 1H, J =1,1, J =7,6 Hz, H4); 7.32–7.48 (m, 6H, H—Ar); 7.72–7.77 (m, 4H, H—Ar). ¹³C-RMN (CDCl₃, 50 MHz) d 19.7 (C(CH₃)₃); 22.8 (3xCH₃); 26.6 (2xCH₃); 87.9 (C2); 117.0 (C5); 121.0 (C7); 121.8 (C4); 127.7 (Ar); 130.0 (Ar); 133.0 (C6); 135.5 (Ar); 142.4 (C3a); 162.4 (C7a); 204.8 (C3). MS (CI) m/z 417 [(M⁺, 74]; 359 (66); 339 (100).

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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
Si1	0.05281 (6)	0.33072 (5)	0.76624 (5)	0.01833 (15)
O1	0.32466 (15)	0.13402 (12)	0.72764 (12)	0.0227 (3)
C2	0.4315 (2)	0.05650 (19)	0.75715 (18)	0.0223 (4)
C3	0.3300 (2)	−0.07888 (19)	0.73025 (18)	0.0227 (4)
C4	0.1727 (2)	−0.07133 (18)	0.68675 (17)	0.0202 (4)
C5	0.0325 (2)	−0.16301 (19)	0.64733 (18)	0.0232 (4)
H5	0.0270	−0.2501	0.6447	0.028*
C6	−0.0980 (2)	−0.1229 (2)	0.61233 (18)	0.0252 (5)
H6	−0.1955	−0.1833	0.5839	0.030*
C7	−0.0885 (2)	0.0057 (2)	0.61825 (18)	0.0236 (4)
H7	−0.1800	0.0311	0.5953	0.028*
C8	0.0501 (2)	0.09704 (18)	0.65653 (17)	0.0193 (4)
C9	0.1812 (2)	0.05545 (18)	0.68970 (16)	0.0188 (4)
C10	0.5136 (2)	0.0626 (2)	0.6729 (2)	0.0296 (5)
H10A	0.4379	0.0327	0.5860	0.044*
H10B	0.5824	0.0083	0.6894	0.044*
H10C	0.5734	0.1508	0.6886	0.044*
C11	0.5402 (2)	0.1070 (2)	0.8933 (2)	0.0316 (5)
H11A	0.5988	0.1955	0.9086	0.047*
H11B	0.6109	0.0548	0.9159	0.047*
H11C	0.4813	0.1033	0.9434	0.047*
O12	0.37919 (16)	−0.17058 (14)	0.74359 (14)	0.0320 (4)
O13	0.06209 (15)	0.22261 (12)	0.65909 (12)	0.0217 (3)
C14	0.0978 (2)	0.27196 (18)	0.90971 (18)	0.0212 (4)
C15	0.2433 (2)	0.2591 (2)	0.97519 (19)	0.0270 (5)
H15	0.3220	0.2867	0.9493	0.032*
C16	0.2760 (3)	0.2073 (2)	1.0766 (2)	0.0323 (5)
H16	0.3764	0.2007	1.1200	0.039*
C17	0.1623 (3)	0.1654 (2)	1.1145 (2)	0.0358 (6)
H17	0.1840	0.1291	1.1837	0.043*
C18	0.0170 (3)	0.1763 (2)	1.0515 (2)	0.0371 (6)
H18	−0.0613	0.1476	1.0776	0.045*
C19	−0.0147 (2)	0.2288 (2)	0.9508 (2)	0.0285 (5)
H19	−0.1151	0.2358	0.9084	0.034*
C20	−0.1450 (2)	0.34886 (18)	0.70512 (18)	0.0215 (4)
C21	−0.2426 (2)	0.3037 (2)	0.57890 (19)	0.0253 (5)
H21	−0.2115	0.2558	0.5252	0.030*
C22	−0.3847 (2)	0.3276 (2)	0.5300 (2)	0.0337 (5)
H22	−0.4498	0.2958	0.4438	0.040*
C23	−0.4303 (3)	0.3977 (2)	0.6075 (2)	0.0379 (6)
H23	−0.5273	0.4139	0.5748	0.045*
C24	−0.3351 (3)	0.4442 (2)	0.7324 (2)	0.0365 (6)
H24	−0.3665	0.4928	0.7854	0.044*
C25	−0.1943 (2)	0.4205 (2)	0.7807 (2)	0.0281 (5)
H25	−0.1298	0.4534	0.8668	0.034*
C26	0.1895 (2)	0.48211 (19)	0.77629 (18)	0.0220 (4)
C27	0.3543 (3)	0.4743 (2)	0.8183 (3)	0.0462 (7)
H27A	0.3558	0.3973	0.7669	0.069*
H27B	0.3951	0.4711	0.9054	0.069*
H27C	0.4179	0.5495	0.8094	0.069*
C28	0.1375 (3)	0.5049 (2)	0.6466 (2)	0.0318 (5)
H28A	0.2037	0.5858	0.6497	0.048*
H28B	0.0312	0.5086	0.6170	0.048*
H28C	0.1442	0.4351	0.5899	0.048*
C29	0.1862 (3)	0.5957 (2)	0.8649 (2)	0.0428 (6)
H29A	0.2554	0.6739	0.8663	0.064*
H29B	0.2195	0.5823	0.9486	0.064*
H29C	0.0816	0.6034	0.8363	0.064*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Si1	0.0189 (3)	0.0199 (3)	0.0175 (3)	0.0066 (2)	0.0087 (2)	0.0046 (2)
O1	0.0195 (7)	0.0194 (7)	0.0283 (8)	0.0056 (6)	0.0088 (6)	0.0070 (6)
C2	0.0201 (10)	0.0210 (10)	0.0256 (11)	0.0085 (8)	0.0076 (8)	0.0069 (8)
C3	0.0243 (10)	0.0234 (11)	0.0208 (10)	0.0083 (9)	0.0085 (8)	0.0074 (8)
C4	0.0240 (10)	0.0208 (10)	0.0156 (9)	0.0069 (8)	0.0079 (8)	0.0050 (8)
C5	0.0268 (11)	0.0190 (10)	0.0223 (10)	0.0033 (8)	0.0104 (9)	0.0050 (8)
C6	0.0222 (10)	0.0266 (11)	0.0236 (11)	0.0009 (9)	0.0100 (9)	0.0052 (9)
C7	0.0205 (10)	0.0326 (12)	0.0201 (10)	0.0096 (9)	0.0101 (8)	0.0069 (9)
C8	0.0259 (10)	0.0199 (10)	0.0158 (9)	0.0094 (8)	0.0112 (8)	0.0047 (8)
C9	0.0204 (10)	0.0206 (10)	0.0143 (9)	0.0031 (8)	0.0080 (8)	0.0034 (8)
C10	0.0266 (11)	0.0322 (12)	0.0336 (12)	0.0105 (9)	0.0142 (10)	0.0112 (10)
C11	0.0284 (12)	0.0297 (12)	0.0289 (12)	0.0059 (9)	0.0057 (10)	0.0058 (9)
O12	0.0287 (8)	0.0236 (8)	0.0416 (9)	0.0108 (7)	0.0098 (7)	0.0110 (7)
O13	0.0280 (8)	0.0216 (7)	0.0207 (7)	0.0119 (6)	0.0128 (6)	0.0069 (6)
C14	0.0268 (11)	0.0175 (10)	0.0200 (10)	0.0074 (8)	0.0104 (8)	0.0037 (8)
C15	0.0280 (11)	0.0293 (12)	0.0264 (11)	0.0100 (9)	0.0122 (9)	0.0095 (9)
C16	0.0369 (13)	0.0359 (13)	0.0252 (11)	0.0173 (10)	0.0097 (10)	0.0105 (10)
C17	0.0558 (16)	0.0353 (13)	0.0273 (12)	0.0228 (12)	0.0210 (11)	0.0163 (10)
C18	0.0502 (15)	0.0418 (14)	0.0389 (13)	0.0194 (12)	0.0320 (12)	0.0210 (11)
C19	0.0288 (12)	0.0326 (12)	0.0320 (12)	0.0124 (10)	0.0176 (10)	0.0124 (10)
C20	0.0228 (10)	0.0199 (10)	0.0260 (11)	0.0077 (8)	0.0126 (9)	0.0096 (8)
C21	0.0257 (11)	0.0277 (11)	0.0259 (11)	0.0085 (9)	0.0122 (9)	0.0117 (9)
C22	0.0250 (11)	0.0424 (14)	0.0337 (13)	0.0103 (10)	0.0083 (10)	0.0196 (11)
C23	0.0256 (12)	0.0436 (14)	0.0563 (16)	0.0199 (11)	0.0193 (11)	0.0265 (12)
C24	0.0360 (13)	0.0348 (13)	0.0538 (16)	0.0188 (11)	0.0286 (12)	0.0160 (12)
C25	0.0295 (12)	0.0258 (11)	0.0336 (12)	0.0089 (9)	0.0175 (10)	0.0079 (9)
C26	0.0208 (10)	0.0221 (10)	0.0208 (10)	0.0026 (8)	0.0087 (8)	0.0043 (8)
C27	0.0239 (12)	0.0448 (15)	0.0687 (18)	0.0044 (11)	0.0147 (12)	0.0314 (14)
C28	0.0398 (13)	0.0257 (12)	0.0271 (11)	0.0042 (10)	0.0131 (10)	0.0091 (9)
C29	0.0602 (17)	0.0235 (12)	0.0409 (14)	−0.0067 (11)	0.0316 (13)	−0.0038 (10)

Geometric parameters (Å, º) top

Si1—O13	1.6627 (14)	C16—C17	1.381 (3)
Si1—C14	1.866 (2)	C16—H16	0.9500
Si1—C20	1.866 (2)	C17—C18	1.381 (3)
Si1—C26	1.878 (2)	C17—H17	0.9500
O1—C9	1.358 (2)	C18—C19	1.382 (3)
O1—C2	1.465 (2)	C18—H18	0.9500
C2—C11	1.513 (3)	C19—H19	0.9500
C2—C10	1.515 (3)	C20—C21	1.396 (3)
C2—C3	1.532 (3)	C20—C25	1.400 (3)
C3—O12	1.218 (2)	C21—C22	1.394 (3)
C3—C4	1.457 (3)	C21—H21	0.9500
C4—C9	1.384 (3)	C22—C23	1.382 (3)
C4—C5	1.394 (3)	C22—H22	0.9500
C5—C6	1.379 (3)	C23—C24	1.379 (3)
C5—H5	0.9500	C23—H23	0.9500
C6—C7	1.398 (3)	C24—C25	1.381 (3)
C6—H6	0.9500	C24—H24	0.9500
C7—C8	1.383 (3)	C25—H25	0.9500
C7—H7	0.9500	C26—C28	1.526 (3)
C8—O13	1.367 (2)	C26—C27	1.529 (3)
C8—C9	1.393 (3)	C26—C29	1.534 (3)
C10—H10A	0.9800	C27—H27A	0.9800
C10—H10B	0.9800	C27—H27B	0.9800
C10—H10C	0.9800	C27—H27C	0.9800
C11—H11A	0.9800	C28—H28A	0.9800
C11—H11B	0.9800	C28—H28B	0.9800
C11—H11C	0.9800	C28—H28C	0.9800
C14—C15	1.397 (3)	C29—H29A	0.9800
C14—C19	1.400 (3)	C29—H29B	0.9800
C15—C16	1.383 (3)	C29—H29C	0.9800
C15—H15	0.9500

O13—Si1—C14	107.62 (8)	C17—C16—H16	120.1
O13—Si1—C20	108.10 (8)	C15—C16—H16	120.1
C14—Si1—C20	111.46 (9)	C18—C17—C16	119.8 (2)
O13—Si1—C26	103.79 (8)	C18—C17—H17	120.1
C14—Si1—C26	116.95 (9)	C16—C17—H17	120.1
C20—Si1—C26	108.36 (9)	C17—C18—C19	120.2 (2)
C9—O1—C2	107.46 (14)	C17—C18—H18	119.9
O1—C2—C11	107.94 (16)	C19—C18—H18	119.9
O1—C2—C10	108.69 (16)	C18—C19—C14	121.5 (2)
C11—C2—C10	112.76 (17)	C18—C19—H19	119.3
O1—C2—C3	104.86 (15)	C14—C19—H19	119.3
C11—C2—C3	111.31 (17)	C21—C20—C25	117.43 (18)
C10—C2—C3	110.89 (17)	C21—C20—Si1	120.75 (15)
O12—C3—C4	129.89 (19)	C25—C20—Si1	121.41 (16)
O12—C3—C2	123.83 (18)	C22—C21—C20	121.4 (2)
C4—C3—C2	106.28 (16)	C22—C21—H21	119.3
C9—C4—C5	121.40 (18)	C20—C21—H21	119.3
C9—C4—C3	106.16 (17)	C23—C22—C21	119.6 (2)
C5—C4—C3	132.44 (18)	C23—C22—H22	120.2
C6—C5—C4	117.65 (19)	C21—C22—H22	120.2
C6—C5—H5	121.2	C24—C23—C22	120.0 (2)
C4—C5—H5	121.2	C24—C23—H23	120.0
C5—C6—C7	120.71 (19)	C22—C23—H23	120.0
C5—C6—H6	119.6	C23—C24—C25	120.3 (2)
C7—C6—H6	119.6	C23—C24—H24	119.8
C8—C7—C6	121.96 (18)	C25—C24—H24	119.8
C8—C7—H7	119.0	C24—C25—C20	121.3 (2)
C6—C7—H7	119.0	C24—C25—H25	119.4
O13—C8—C7	123.14 (17)	C20—C25—H25	119.4
O13—C8—C9	119.85 (17)	C28—C26—C27	107.98 (18)
C7—C8—C9	116.99 (18)	C28—C26—C29	108.62 (18)
O1—C9—C4	115.22 (17)	C27—C26—C29	109.12 (19)
O1—C9—C8	123.50 (17)	C28—C26—Si1	107.54 (14)
C4—C9—C8	121.27 (17)	C27—C26—Si1	112.54 (15)
C2—C10—H10A	109.5	C29—C26—Si1	110.90 (14)
C2—C10—H10B	109.5	C26—C27—H27A	109.5
H10A—C10—H10B	109.5	C26—C27—H27B	109.5
C2—C10—H10C	109.5	H27A—C27—H27B	109.5
H10A—C10—H10C	109.5	C26—C27—H27C	109.5
H10B—C10—H10C	109.5	H27A—C27—H27C	109.5
C2—C11—H11A	109.5	H27B—C27—H27C	109.5
C2—C11—H11B	109.5	C26—C28—H28A	109.5
H11A—C11—H11B	109.5	C26—C28—H28B	109.5
C2—C11—H11C	109.5	H28A—C28—H28B	109.5
H11A—C11—H11C	109.5	C26—C28—H28C	109.5
H11B—C11—H11C	109.5	H28A—C28—H28C	109.5
C8—O13—Si1	126.65 (12)	H28B—C28—H28C	109.5
C15—C14—C19	116.86 (18)	C26—C29—H29A	109.5
C15—C14—Si1	120.96 (15)	C26—C29—H29B	109.5
C19—C14—Si1	121.97 (15)	H29A—C29—H29B	109.5
C16—C15—C14	121.9 (2)	C26—C29—H29C	109.5
C16—C15—H15	119.0	H29A—C29—H29C	109.5
C14—C15—H15	119.0	H29B—C29—H29C	109.5
C17—C16—C15	119.7 (2)

C9—O1—C2—C11	−118.39 (17)	C26—Si1—C14—C15	−50.63 (19)
C9—O1—C2—C10	119.01 (17)	O13—Si1—C14—C19	−108.91 (17)
C9—O1—C2—C3	0.37 (19)	C20—Si1—C14—C19	9.4 (2)
O1—C2—C3—O12	179.64 (18)	C26—Si1—C14—C19	134.85 (17)
C11—C2—C3—O12	−63.9 (3)	C19—C14—C15—C16	−0.6 (3)
C10—C2—C3—O12	62.5 (3)	Si1—C14—C15—C16	−175.34 (17)
O1—C2—C3—C4	0.30 (19)	C14—C15—C16—C17	0.8 (3)
C11—C2—C3—C4	116.76 (18)	C15—C16—C17—C18	−0.5 (3)
C10—C2—C3—C4	−116.84 (18)	C16—C17—C18—C19	0.1 (4)
O12—C3—C4—C9	179.9 (2)	C17—C18—C19—C14	0.1 (4)
C2—C3—C4—C9	−0.8 (2)	C15—C14—C19—C18	0.1 (3)
O12—C3—C4—C5	−0.2 (4)	Si1—C14—C19—C18	174.87 (17)
C2—C3—C4—C5	179.0 (2)	O13—Si1—C20—C21	−16.23 (18)
C9—C4—C5—C6	−0.6 (3)	C14—Si1—C20—C21	−134.30 (16)
C3—C4—C5—C6	179.51 (19)	C26—Si1—C20—C21	95.65 (17)
C4—C5—C6—C7	−0.9 (3)	O13—Si1—C20—C25	171.27 (15)
C5—C6—C7—C8	1.3 (3)	C14—Si1—C20—C25	53.20 (19)
C6—C7—C8—O13	177.67 (17)	C26—Si1—C20—C25	−76.85 (18)
C6—C7—C8—C9	−0.2 (3)	C25—C20—C21—C22	−0.8 (3)
C2—O1—C9—C4	−1.0 (2)	Si1—C20—C21—C22	−173.60 (16)
C2—O1—C9—C8	178.51 (17)	C20—C21—C22—C23	0.3 (3)
C5—C4—C9—O1	−178.72 (16)	C21—C22—C23—C24	0.3 (3)
C3—C4—C9—O1	1.2 (2)	C22—C23—C24—C25	−0.3 (3)
C5—C4—C9—C8	1.8 (3)	C23—C24—C25—C20	−0.2 (3)
C3—C4—C9—C8	−178.34 (17)	C21—C20—C25—C24	0.8 (3)
O13—C8—C9—O1	1.3 (3)	Si1—C20—C25—C24	173.55 (16)
C7—C8—C9—O1	179.22 (17)	O13—Si1—C26—C28	56.95 (15)
O13—C8—C9—C4	−179.26 (16)	C14—Si1—C26—C28	175.28 (13)
C7—C8—C9—C4	−1.3 (3)	C20—Si1—C26—C28	−57.78 (16)
C7—C8—O13—Si1	78.3 (2)	O13—Si1—C26—C27	−61.85 (17)
C9—C8—O13—Si1	−103.83 (18)	C14—Si1—C26—C27	56.47 (19)
C14—Si1—O13—C8	21.23 (17)	C20—Si1—C26—C27	−176.58 (16)
C20—Si1—O13—C8	−99.27 (16)	O13—Si1—C26—C29	175.59 (15)
C26—Si1—O13—C8	145.81 (15)	C14—Si1—C26—C29	−66.09 (18)
O13—Si1—C14—C15	65.61 (18)	C20—Si1—C26—C29	60.85 (17)
C20—Si1—C14—C15	−176.04 (16)

Experimental details

Crystal data
Chemical formula	C₂₆H₂₈O₃Si
M_r	416.57
Crystal system, space group	Triclinic, P1
Temperature (K)	100
a, b, c (Å)	9.8210 (18), 11.081 (2), 12.025 (2)
α, β, γ (°)	98.803 (2), 112.151 (2), 101.791 (2)
V (Å³)	1147.7 (4)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.13
Crystal size (mm)	0.49 × 0.43 × 0.10

Data collection
Diffractometer	Bruker SMART 1000 CCD diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2001)
T_min, T_max	0.941, 0.988
No. of measured, independent and observed [I > 2σ(I)] reflections	14369, 4197, 3325
R_int	0.032
(sin θ/λ)_max (Å⁻¹)	0.602

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.044, 0.111, 1.05
No. of reflections	4197
No. of parameters	276
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.83, −0.29

Computer programs: SMART (Bruker, 2007), SAINT (Bruker, 2007), SIR97 (Altomare et al., 1999), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999).

Acknowledgements

We gratefully acknowledge the Unidade de Raios X, RIAIDT, University of Santiago de Compostela, Spain.

References

Altomare, A., Burla, M. C., Camalli, M., Cascarano, G. L., Giacovazzo, C., Guagliardi, A., Moliterni, A. G. G., Polidori, G. & Spagna, R. (1999). J. Appl. Cryst. 32, 115–119. Web of Science CrossRef CAS IUCr Journals Google Scholar
Braun, M., Hessamian-Alinejad, A., de Lacroix, B. F., Álvarez, B. H. & Fischer, G. (2008). Molecules, 13, 995–1003. Web of Science CrossRef PubMed CAS Google Scholar
Bruker (2001). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Bruker (2007). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838. CrossRef CAS IUCr Journals Google Scholar
Foroumadi, A., Zamanian, S., Samzadeh-Kermani, A. & Shafiee, A. (2009). Synth. Commun. 39, 1722–1728. Web of Science CrossRef CAS Google Scholar
Löser, R., Chlupacova, M., Marecek, A., Opletanova, V. & Gütschow, M. (2004). Helv. Chim. Acta, 87, 2597–2601. Google Scholar
Schoepfer, J., Fretz, H., Chaudhuri, B., Muller, L., Seeber, E., Meijer, L., Lozach, O., Vangrevelinghe, E. & Furet, P. (2002). J. Med. Chem. 45, 1741–1747. Web of Science CrossRef PubMed CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Venkatesan, A. M., Dos Santos, O., Ellingboe, J., Edvard, D. A., Harrison, B. L., Smith, D. L., Scerni, R., Hornby, G. A., Schechter, L. E. & Andree, T. H. (2010). Bioorg. Med. Chem. 20, 824–827. CrossRef CAS Google Scholar
Zhou, G., Zhu, J., Xie, Z. & Li, Y. (2008). Org. Lett. 10, 721–724. Web of Science CrossRef PubMed CAS Google Scholar