rac-(3aR,6aR)-(E)-Methyl 2-(3a-methyl­perhydro­furo[3,2-b]furan-2-yl­idene)acetate

Bellovičová, L.; Kožíšek, J.; Doháňošová, J.; Lásiková, A.; Gracza, T.

doi:10.1107/S1600536810032101

organic compounds

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ISSN: 2056-9890

Volume 66| Part 9| September 2010| Page o2381

https://doi.org/10.1107/S1600536810032101

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rac-(3aR,6aR)-(E)-Methyl 2-(3a-methylperhydrofuro[3,2-b]furan-2-ylidene)acetate

Lenka Bellovičová,^a Jozef Kožíšek,^a ^* Jana Doháňošová,^b Angelika Lásiková ^b and Tibor Gracza ^b

^aDepartment of Physical Chemistry, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, SK-812 37 Bratislava, Slovak Republic, and ^bDepartment of Organic Chemistry, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, SK-812 37 Bratislava, Slovak Republic
^*Correspondence e-mail: jozef.kozisek@stuba.sk

(Received 7 May 2010; accepted 10 August 2010; online 21 August 2010)

The constitution and relative configuration at the stereogenic centres and stereochemistry of the C—C double bond formed during Pd^II-catalysed domino reaction was established by X-ray analysis of the title compound, C₁₀H₁₄O₄. The asymmetric unit contains two molecules.

Related literature

The title compound was prepared from 4-methylpent-4-en-1,3-diol (Breit & Zahn, 2001 ) by a modified procedure for carbonylation of alkene-3-ol (Semmelhack & Epa, 1993 ).

Experimental

Crystal data

C₁₀H₁₄O₄
M_r = 198.21
Monoclinic, P 2₁ /n
a = 12.159 (1) Å
b = 5.8100 (3) Å
c = 28.509 (1) Å
β = 101.51 (1)°
V = 1973.5 (2) Å³
Z = 8
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 293 K
0.84 × 0.36 × 0.12 mm

Data collection

Oxford Diffraction Gemini R CCD diffractometer
Absorption correction: analytical [CrysAlis PRO (Oxford Diffraction, 2010 $[Oxford Diffraction (2010). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, England.]$ ); analytical numeric absorption correction using a multi-faceted crystal model based on expressions derived by Clark & Reid (1995 )] T_min = 0.941, T_max = 0.988
59312 measured reflections
4033 independent reflections
3571 reflections with I > 2σ(I)
R_int = 0.024

Refinement

R[F² > 2σ(F²)] = 0.036
wR(F²) = 0.091
S = 1.05
4025 reflections
254 parameters
H-atom parameters constrained
Δρ_max = 0.32 e Å⁻³
Δρ_min = −0.22 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2009 $[Oxford Diffraction (2009). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Yarnton, England.]$ ); cell refinement: CrysAlis CCD; data reduction: CrysAlis RED (Oxford Diffraction, 2009 $[Oxford Diffraction (2009). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Yarnton, England.]$ ); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1998 ); software used to prepare material for publication: enCIFer (Allen et al., 2004 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: https://doi.org/10.1107/S1600536810032101/bv2142sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810032101/bv2142Isup2.hkl

checkCIF report

Comment top

As a part of our long term program directed towards the application of palladium(II)-catalysed oxycarbonylation of unsaturated polyols in the natural product synthesis we studied the domino Pd(II)-promoted reactions. The title compound, [(I): alternative name: (±)-(1'R, 5'R)-(E)-methyl 2-(5'-methyl-2',6'-dioxabicyclo[3.3.0]octa-3'-ylidene) acetate] represents a product of the first diastereoselective domino intramolecular Wacker-type cyclization - Heck reaction - cyclization of 4-methylpent-4-en-1,3-diol with methyl acrylate. The asymmetric unit contains two molecules of the same chirality (Z' = 2), but as the space group is centrosymmetric, both enantiomers are present in the unit cell.

Related literature top

The title compound was prepared from 4-methylpent-4-en-1,3-diol (Breit & Zahn, 2001) by a modified procedure for carbonylation of alkene-3-ol (Semmelhack & Epa, 1993).

Experimental top

The title compound was prepared from 4-methylpent-4-en-1,3-diol (Breit and Zahn, 2001) by a modified procedure for carbonylation of alkene-3-ol (Semmelhack and Epa, 1993). A mixture of 4-methylpent-4-en-1,3-diol (200 mg, 1.70 mmol, 1 equivalent) and CuCl freshly recrystallized (170 mg, 1.70 mmol, 1 equivalent) in dry DMF (7 ml) was stirred at r.t for 10 min. under oxygen atmosphere (balloon). The methyl acrylate (0.8 ml, 8.60 mmol, 5 equivalents) and palladium acetate (39 mg, 0.17 mmol, 0.1 equivalent) were then added. The mixture was stirred for 56 h, then diluted by ethyl acetate (100 ml). The organic solution was washed three times with sat. aq. ammonium chloride solution, driedover anhydrous magnesium sulfate, and concentrated in vacuo. The residue was purified by flash chromatography (SiO₂, ethyl acetate-hexane-3:1, Rf 0.73). The title compound was slowly crystallized from hexane to give white crystals [m.p. 65–67 °C].¹H NMR (300 MHz, Varian, CDCl₃): δ(p.p.m.) = 1.43 (s, 3H, CH₃); 2.17 (m, 2H, H-8'); 2.96 3.64 (2xd, 2H, J=19.7, H-4'); 3.69–4.04 (m, 6H, H-1', H-7', OCH₃); 4.66 (d, 1H, J= 6.3 Hz, H-2). ¹³C NMR (75 MHz, CDCl₃): δ(p.p.m.) = 22.7 (q, CH₃), 32.7 (t, C-8'), 44.2 (t, C-4'), 50.8 (q, OCH₃), 66.9 (t, C-7'), 87.7 (s, C-5'), 89.9 (d, C-1'), 91.3 (d, C-2), 168.7 (s, C-1), 175.7 (d, C-3'). IČ, film: ν(cm^-1) = 3479 (w), 2975 (m), 2951 (m), 2874 (w), 1789 (w), 1705 (s), 1645 (s), 1437 (s), 1410 (w), 1364 (s), 1317 (m), 1274 (m), 1193 (s), 1148 (s), 1106 (s), 1093 (s), 1039 (s), 1010 (m), 978 (m), 950 (w), 933 (w), 900 (w), 871 (w), 822 (m), 734 (w), 592 (w) [cm^-1]

Structure description top

The title compound was prepared from 4-methylpent-4-en-1,3-diol (Breit & Zahn, 2001) by a modified procedure for carbonylation of alkene-3-ol (Semmelhack & Epa, 1993).

Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2009); cell refinement: CrysAlis CCD (Oxford Diffraction, 2009); data reduction: CrysAlis RED (Oxford Diffraction, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1998); software used to prepare material for publication: enCIFer (Allen et al., 2004).

Figures top

	Fig. 1. The numbering scheme of title compound. Displacement ellipsoids are shown at the 50% probability level.
	Fig. 2. Synthesis of rac-(3aR, 6aR)-(E)-methyl 2-(3a-methyl-tetrahydrofuro [3,2-b]furan-2-ylidene)acetate.

rac-(3aR,6aR)-(E)-methyl 2-(3a-methylperhydrofuro[3,2-b]furan-2-ylidene)acetate top

Crystal data top

C₁₀H₁₄O₄	F(000) = 848
M_r = 198.21	D_x = 1.334 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 35551 reflections
a = 12.159 (1) Å	θ = 3.6–29.5°
b = 5.8100 (3) Å	µ = 0.10 mm⁻¹
c = 28.509 (1) Å	T = 293 K
β = 101.51 (1)°	Block, colorless
V = 1973.5 (2) Å³	0.84 × 0.36 × 0.12 mm
Z = 8

Data collection top

Oxford Diffraction Gemini R CCD diffractometer	4033 independent reflections
Radiation source: Enhance (Mo) X-ray Source	3571 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.024
Detector resolution: 10.4340 pixels mm^-1	θ_max = 26.4°, θ_min = 3.6°
Rotation method data acquisition using ω and φ scans	h = −15→15
Absorption correction: analytical [CrysAlis PRO (Oxford Diffraction, 2010); analytical numeric absorption correction using a multi-faceted crystal model based on expressions derived by Clark & Reid (1995)]	k = −7→7
T_min = 0.941, T_max = 0.988	l = −35→35
59312 measured reflections

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.036	H-atom parameters constrained
wR(F²) = 0.091	w = 1/[σ²(F_o²) + (0.0375P)² + 1.2579P] where P = (F_o² + 2F_c²)/3
S = 1.05	(Δ/σ)_max = 0.001
4025 reflections	Δρ_max = 0.32 e Å⁻³
254 parameters	Δρ_min = −0.22 e Å⁻³
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0031 (7)

Crystal data top

C₁₀H₁₄O₄	V = 1973.5 (2) Å³
M_r = 198.21	Z = 8
Monoclinic, P2₁/n	Mo Kα radiation
a = 12.159 (1) Å	µ = 0.10 mm⁻¹
b = 5.8100 (3) Å	T = 293 K
c = 28.509 (1) Å	0.84 × 0.36 × 0.12 mm
β = 101.51 (1)°

Data collection top

Oxford Diffraction Gemini R CCD diffractometer	4033 independent reflections
Absorption correction: analytical [CrysAlis PRO (Oxford Diffraction, 2010); analytical numeric absorption correction using a multi-faceted crystal model based on expressions derived by Clark & Reid (1995)]	3571 reflections with I > 2σ(I)
T_min = 0.941, T_max = 0.988	R_int = 0.024
59312 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.036	0 restraints
wR(F²) = 0.091	H-atom parameters constrained
S = 1.05	Δρ_max = 0.32 e Å⁻³
4025 reflections	Δρ_min = −0.22 e Å⁻³
254 parameters

Special details top

Experimental. CrysAlisPro, Oxford Diffraction Ltd., Version 1.171.33.62 (release 16-03-2010 CrysAlis171 .NET) (compiled Mar 16 2010,16:26:05) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897)

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.

independent reflections were 4033, 7 inconsistent equivalents, 4025 were used in the refinement

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
C2	0.35925 (10)	0.2368 (2)	0.34753 (4)	0.0173 (3)
C3	0.35197 (10)	0.4998 (2)	0.34359 (4)	0.0174 (3)
H3A	0.4074	0.5638	0.3265	0.021*
C4	0.36899 (10)	0.5847 (2)	0.39470 (4)	0.0195 (3)
H4B	0.3319	0.7311	0.3967	0.023*
H4A	0.4481	0.5997	0.4089	0.023*
C5	0.31418 (11)	0.3932 (2)	0.41825 (4)	0.0212 (3)
H5B	0.3475	0.3829	0.4521	0.025*
H5A	0.2344	0.4214	0.4149	0.025*
C7	0.18323 (10)	0.3541 (2)	0.30141 (4)	0.0177 (3)
C8	0.26323 (10)	0.1555 (2)	0.30792 (4)	0.0192 (3)
H8B	0.2897	0.1237	0.2786	0.023*
H8A	0.2282	0.0180	0.3175	0.023*
C9	0.47359 (10)	0.1376 (2)	0.34558 (5)	0.0212 (3)
H9C	0.4713	−0.0270	0.3484	0.025*
H9B	0.5286	0.1989	0.3715	0.025*
H9A	0.4933	0.1779	0.3157	0.025*
C10	0.07393 (10)	0.3673 (2)	0.28094 (4)	0.0197 (3)
H10A	0.0379	0.5089	0.2799	0.024*
C11	0.01014 (10)	0.1674 (2)	0.26033 (4)	0.0189 (3)
C14	−0.16945 (12)	0.0392 (3)	0.22261 (6)	0.0306 (3)
H14C	−0.2446	0.0946	0.2118	0.037*
H14B	−0.1693	−0.0791	0.2461	0.037*
H14A	−0.1416	−0.0225	0.1960	0.037*
C16	0.86595 (10)	0.9608 (2)	0.38508 (4)	0.0190 (3)
C17	0.96259 (11)	1.0068 (2)	0.42723 (4)	0.0200 (3)
H17A	0.9589	1.1601	0.4412	0.024*
C18	1.06680 (11)	0.9721 (2)	0.40691 (5)	0.0247 (3)
H18B	1.1303	0.9277	0.4316	0.030*
H18A	1.0857	1.1098	0.3910	0.030*
C19	1.03089 (11)	0.7781 (3)	0.37159 (5)	0.0255 (3)
H19B	1.0714	0.7855	0.3456	0.031*
H19A	1.0452	0.6299	0.3873	0.031*
C21	0.85362 (10)	0.7177 (2)	0.45081 (4)	0.0177 (3)
C22	0.78158 (10)	0.8268 (2)	0.40773 (4)	0.0206 (3)
H22B	0.7264	0.9290	0.4169	0.025*
H22A	0.7431	0.7111	0.3859	0.025*
C23	0.81782 (12)	1.1718 (2)	0.35705 (5)	0.0270 (3)
H23C	0.7581	1.1263	0.3314	0.032*
H23B	0.8756	1.2467	0.3442	0.032*
H23A	0.7893	1.2760	0.3779	0.032*
C24	0.83161 (10)	0.5412 (2)	0.47796 (4)	0.0190 (3)
H24A	0.8872	0.4903	0.5031	0.023*
C25	0.72309 (11)	0.4285 (2)	0.46889 (4)	0.0201 (3)
C28	0.61577 (12)	0.1322 (3)	0.49483 (5)	0.0279 (3)
H28C	0.6234	0.0062	0.5170	0.033*
H28B	0.5913	0.0751	0.4628	0.033*
H28A	0.5615	0.2395	0.5021	0.033*
O1	0.33343 (8)	0.18484 (15)	0.39400 (3)	0.0210 (2)
O6	0.23724 (7)	0.54910 (15)	0.31945 (3)	0.0197 (2)
O12	0.04472 (8)	−0.02687 (16)	0.25726 (3)	0.0231 (2)
O13	−0.09856 (7)	0.22621 (17)	0.24354 (3)	0.0248 (2)
O15	0.91270 (7)	0.81006 (17)	0.35392 (3)	0.0232 (2)
O20	0.95504 (7)	0.82156 (16)	0.46110 (3)	0.0205 (2)
O26	0.64051 (8)	0.48260 (19)	0.43955 (4)	0.0318 (3)
O27	0.72256 (7)	0.24603 (16)	0.49859 (3)	0.0239 (2)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C2	0.0185 (6)	0.0160 (6)	0.0180 (6)	−0.0016 (5)	0.0051 (5)	−0.0007 (5)
C3	0.0155 (6)	0.0168 (6)	0.0198 (6)	−0.0014 (5)	0.0032 (4)	0.0003 (5)
C4	0.0191 (6)	0.0178 (6)	0.0204 (6)	0.0004 (5)	0.0012 (5)	−0.0026 (5)
C5	0.0257 (6)	0.0192 (6)	0.0193 (6)	0.0023 (5)	0.0059 (5)	−0.0015 (5)
C7	0.0227 (6)	0.0163 (6)	0.0147 (5)	−0.0028 (5)	0.0050 (5)	−0.0003 (5)
C8	0.0192 (6)	0.0168 (6)	0.0217 (6)	−0.0007 (5)	0.0041 (5)	−0.0019 (5)
C9	0.0190 (6)	0.0199 (6)	0.0246 (6)	0.0001 (5)	0.0044 (5)	−0.0008 (5)
C10	0.0214 (6)	0.0181 (6)	0.0189 (6)	0.0016 (5)	0.0024 (5)	−0.0004 (5)
C11	0.0195 (6)	0.0226 (6)	0.0150 (5)	−0.0006 (5)	0.0041 (5)	0.0002 (5)
C14	0.0212 (7)	0.0321 (8)	0.0356 (8)	−0.0056 (6)	−0.0011 (6)	−0.0088 (6)
C16	0.0199 (6)	0.0196 (6)	0.0176 (6)	0.0025 (5)	0.0041 (5)	−0.0012 (5)
C17	0.0246 (6)	0.0179 (6)	0.0168 (6)	−0.0026 (5)	0.0022 (5)	0.0013 (5)
C18	0.0198 (6)	0.0295 (7)	0.0242 (6)	−0.0041 (5)	0.0029 (5)	0.0051 (6)
C19	0.0200 (6)	0.0307 (7)	0.0265 (7)	0.0047 (5)	0.0062 (5)	0.0011 (6)
C21	0.0163 (6)	0.0210 (6)	0.0160 (6)	0.0008 (5)	0.0032 (4)	−0.0031 (5)
C22	0.0178 (6)	0.0242 (6)	0.0195 (6)	0.0029 (5)	0.0029 (5)	0.0025 (5)
C23	0.0314 (7)	0.0261 (7)	0.0234 (6)	0.0069 (6)	0.0052 (5)	0.0065 (6)
C24	0.0166 (6)	0.0231 (6)	0.0165 (6)	0.0007 (5)	0.0012 (4)	0.0012 (5)
C25	0.0206 (6)	0.0233 (6)	0.0171 (6)	−0.0001 (5)	0.0055 (5)	−0.0002 (5)
C28	0.0256 (7)	0.0306 (7)	0.0281 (7)	−0.0105 (6)	0.0070 (5)	0.0010 (6)
O1	0.0282 (5)	0.0169 (4)	0.0198 (4)	−0.0007 (4)	0.0090 (4)	0.0002 (3)
O6	0.0196 (4)	0.0157 (4)	0.0214 (4)	−0.0003 (3)	−0.0013 (3)	−0.0007 (3)
O12	0.0236 (5)	0.0209 (5)	0.0239 (5)	−0.0012 (4)	0.0029 (4)	−0.0036 (4)
O13	0.0181 (4)	0.0262 (5)	0.0274 (5)	−0.0016 (4)	−0.0014 (4)	−0.0060 (4)
O15	0.0203 (5)	0.0283 (5)	0.0209 (4)	0.0026 (4)	0.0038 (4)	−0.0062 (4)
O20	0.0195 (4)	0.0232 (5)	0.0175 (4)	−0.0042 (4)	0.0003 (3)	0.0037 (4)
O26	0.0184 (5)	0.0438 (6)	0.0305 (5)	−0.0051 (4)	−0.0022 (4)	0.0121 (5)
O27	0.0211 (5)	0.0237 (5)	0.0264 (5)	−0.0046 (4)	0.0033 (4)	0.0048 (4)

Geometric parameters (Å, º) top

C2—O1	1.4529 (14)	C16—O15	1.4424 (15)
C2—C9	1.5164 (17)	C16—C23	1.5157 (18)
C2—C8	1.5283 (17)	C16—C17	1.5274 (17)
C2—C3	1.5333 (17)	C16—C22	1.5297 (17)
C3—O6	1.4555 (14)	C17—O20	1.4610 (15)
C3—C4	1.5131 (17)	C17—C18	1.5082 (18)
C3—H3A	0.9800	C17—H17A	0.9800
C4—C5	1.5203 (18)	C18—C19	1.517 (2)
C4—H4B	0.9700	C18—H18B	0.9700
C4—H4A	0.9700	C18—H18A	0.9700
C5—O1	1.4359 (15)	C19—O15	1.4369 (15)
C5—H5B	0.9700	C19—H19B	0.9700
C5—H5A	0.9700	C19—H19A	0.9700
C7—C10	1.3428 (18)	C21—C24	1.3433 (18)
C7—O6	1.3581 (15)	C21—O20	1.3516 (15)
C7—C8	1.4967 (17)	C21—C22	1.4994 (17)
C8—H8B	0.9700	C22—H22B	0.9700
C8—H8A	0.9700	C22—H22A	0.9700
C9—H9C	0.9600	C23—H23C	0.9600
C9—H9B	0.9600	C23—H23B	0.9600
C9—H9A	0.9600	C23—H23A	0.9600
C10—C11	1.4537 (17)	C24—C25	1.4494 (17)
C10—H10A	0.9300	C24—H24A	0.9300
C11—O12	1.2139 (16)	C25—O26	1.2131 (16)
C11—O13	1.3565 (15)	C25—O27	1.3576 (16)
C14—O13	1.4403 (16)	C28—O27	1.4420 (15)
C14—H14C	0.9600	C28—H28C	0.9600
C14—H14B	0.9600	C28—H28B	0.9600
C14—H14A	0.9600	C28—H28A	0.9600

O1—C2—C9	108.71 (10)	O15—C16—C22	109.33 (10)
O1—C2—C8	109.72 (10)	C23—C16—C22	114.41 (11)
C9—C2—C8	115.22 (10)	C17—C16—C22	103.44 (10)
O1—C2—C3	104.73 (10)	O20—C17—C18	108.89 (10)
C9—C2—C3	114.60 (10)	O20—C17—C16	104.54 (10)
C8—C2—C3	103.27 (10)	C18—C17—C16	104.34 (10)
O6—C3—C4	108.98 (10)	O20—C17—H17A	112.8
O6—C3—C2	105.46 (9)	C18—C17—H17A	112.8
C4—C3—C2	105.03 (10)	C16—C17—H17A	112.8
O6—C3—H3A	112.3	C17—C18—C19	101.64 (10)
C4—C3—H3A	112.3	C17—C18—H18B	111.4
C2—C3—H3A	112.3	C19—C18—H18B	111.4
C3—C4—C5	101.48 (10)	C17—C18—H18A	111.4
C3—C4—H4B	111.5	C19—C18—H18A	111.4
C5—C4—H4B	111.5	H18B—C18—H18A	109.3
C3—C4—H4A	111.5	O15—C19—C18	105.78 (11)
C5—C4—H4A	111.5	O15—C19—H19B	110.6
H4B—C4—H4A	109.3	C18—C19—H19B	110.6
O1—C5—C4	106.05 (10)	O15—C19—H19A	110.6
O1—C5—H5B	110.5	C18—C19—H19A	110.6
C4—C5—H5B	110.5	H19B—C19—H19A	108.7
O1—C5—H5A	110.5	C24—C21—O20	119.59 (11)
C4—C5—H5A	110.5	C24—C21—C22	130.07 (11)
H5B—C5—H5A	108.7	O20—C21—C22	110.34 (11)
C10—C7—O6	118.61 (11)	C21—C22—C16	103.27 (10)
C10—C7—C8	131.31 (12)	C21—C22—H22B	111.1
O6—C7—C8	110.06 (10)	C16—C22—H22B	111.1
C7—C8—C2	103.59 (10)	C21—C22—H22A	111.1
C7—C8—H8B	111.0	C16—C22—H22A	111.1
C2—C8—H8B	111.0	H22B—C22—H22A	109.1
C7—C8—H8A	111.0	C16—C23—H23C	109.5
C2—C8—H8A	111.0	C16—C23—H23B	109.5
H8B—C8—H8A	109.0	H23C—C23—H23B	109.5
C2—C9—H9C	109.5	C16—C23—H23A	109.5
C2—C9—H9B	109.5	H23C—C23—H23A	109.5
H9C—C9—H9B	109.5	H23B—C23—H23A	109.5
C2—C9—H9A	109.5	C21—C24—C25	121.40 (11)
H9C—C9—H9A	109.5	C21—C24—H24A	119.3
H9B—C9—H9A	109.5	C25—C24—H24A	119.3
C7—C10—C11	122.15 (12)	O26—C25—O27	121.75 (12)
C7—C10—H10A	118.9	O26—C25—C24	127.21 (12)
C11—C10—H10A	118.9	O27—C25—C24	111.04 (11)
O12—C11—O13	122.40 (12)	O27—C28—H28C	109.5
O12—C11—C10	127.40 (12)	O27—C28—H28B	109.5
O13—C11—C10	110.20 (11)	H28C—C28—H28B	109.5
O13—C14—H14C	109.5	O27—C28—H28A	109.5
O13—C14—H14B	109.5	H28C—C28—H28A	109.5
H14C—C14—H14B	109.5	H28B—C28—H28A	109.5
O13—C14—H14A	109.5	C5—O1—C2	110.45 (9)
H14C—C14—H14A	109.5	C7—O6—C3	111.12 (9)
H14B—C14—H14A	109.5	C11—O13—C14	114.63 (11)
O15—C16—C23	108.93 (10)	C19—O15—C16	110.61 (9)
O15—C16—C17	104.78 (10)	C21—O20—C17	111.13 (9)
C23—C16—C17	115.38 (11)	C25—O27—C28	115.34 (10)

O1—C2—C3—O6	−92.66 (10)	O20—C21—C22—C16	16.47 (13)
C9—C2—C3—O6	148.3 (1)	O15—C16—C22—C21	85.89 (11)
C8—C2—C3—O6	22.21 (12)	C23—C16—C22—C21	−151.64 (11)
O1—C2—C3—C4	22.4 (1)	C17—C16—C22—C21	−25.31 (12)
C9—C2—C3—C4	−96.62 (12)	O20—C21—C24—C25	178.52 (11)
C8—C2—C3—C4	137.27 (10)	C22—C21—C24—C25	−2.3 (2)
O6—C3—C4—C5	79.11 (11)	C21—C24—C25—O26	−4.7 (2)
C2—C3—C4—C5	−33.49 (12)	C21—C24—C25—O27	175.91 (11)
C3—C4—C5—O1	33.07 (12)	C4—C5—O1—C2	−20.25 (13)
C10—C7—C8—C2	−161.49 (13)	C9—C2—O1—C5	121.59 (11)
O6—C7—C8—C2	19.87 (13)	C8—C2—O1—C5	−111.59 (11)
O1—C2—C8—C7	86.28 (11)	C3—C2—O1—C5	−1.33 (13)
C9—C2—C8—C7	−150.66 (10)	C10—C7—O6—C3	175.36 (11)
C3—C2—C8—C7	−24.94 (12)	C8—C7—O6—C3	−5.81 (13)
O6—C7—C10—C11	179.36 (11)	C4—C3—O6—C7	−123.13 (11)
C8—C7—C10—C11	0.8 (2)	C2—C3—O6—C7	−10.82 (13)
C7—C10—C11—O12	−2.6 (2)	O12—C11—O13—C14	0.98 (17)
C7—C10—C11—O13	177.98 (11)	C10—C11—O13—C14	−179.57 (11)
O15—C16—C17—O20	−88.79 (11)	C18—C19—O15—C16	−17.45 (14)
C23—C16—C17—O20	151.4 (1)	C23—C16—O15—C19	119.00 (12)
C22—C16—C17—O20	25.73 (12)	C17—C16—O15—C19	−4.99 (13)
O15—C16—C17—C18	25.5 (1)	C22—C16—O15—C19	−115.31 (11)
C23—C16—C17—C18	−94.26 (13)	C24—C21—O20—C17	179.38 (11)
C22—C16—C17—C18	140.03 (11)	C22—C21—O20—C17	0.07 (14)
O20—C17—C18—C19	76.14 (12)	C18—C17—O20—C21	−127.75 (11)
C16—C17—C18—C19	−35.04 (13)	C16—C17—O20—C21	−16.70 (13)
C17—C18—C19—O15	32.43 (13)	O26—C25—O27—C28	−3.84 (18)
C24—C21—C22—C16	−162.75 (13)	C24—C25—O27—C28	175.63 (11)

Experimental details

Crystal data
Chemical formula	C₁₀H₁₄O₄
M_r	198.21
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	293
a, b, c (Å)	12.159 (1), 5.8100 (3), 28.509 (1)
β (°)	101.51 (1)
V (Å³)	1973.5 (2)
Z	8
Radiation type	Mo Kα
µ (mm⁻¹)	0.10
Crystal size (mm)	0.84 × 0.36 × 0.12

Data collection
Diffractometer	Oxford Diffraction Gemini R CCD
Absorption correction	Analytical [CrysAlis PRO (Oxford Diffraction, 2010); analytical numeric absorption correction using a multi-faceted crystal model based on expressions derived by Clark & Reid (1995)]
T_min, T_max	0.941, 0.988
No. of measured, independent and observed [I > 2σ(I)] reflections	59312, 4033, 3571
R_int	0.024
(sin θ/λ)_max (Å⁻¹)	0.625

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.036, 0.091, 1.05
No. of reflections	4025
No. of parameters	254
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.32, −0.22

Computer programs: CrysAlis CCD (Oxford Diffraction, 2009), CrysAlis RED (Oxford Diffraction, 2009), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 1998), enCIFer (Allen et al., 2004).

Acknowledgements

The authors thank the Grant Agency of Slovak Republic, Grant Nos. VEGA 1/0817/08 and VEGA 1/0115/10, and the Structural Funds, Interreg IIIA, for financial support in purchasing the diffractometer.

References

Allen, F. H., Johnson, O., Shields, G. P., Smith, B. R. & Towler, M. (2004). J. Appl. Cryst. 37, 335–338. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
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Breit, B. & Zahn, S. K. (2001). J. Org. Chem. 66, 4870–4877. Web of Science CrossRef PubMed CAS Google Scholar
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Oxford Diffraction (2010). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, England. Google Scholar
Semmelhack, M. F. & Epa, W. R. (1993). Tetrahedron Lett. 34, 7205–7208. CrossRef CAS Web of Science Google Scholar
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