Ranunculin

Benn, M.; Yelland, L.J.; Parvez, M.

doi:10.1107/S1600536810034847

organic compounds

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ISSN: 2056-9890

Volume 66| Part 10| October 2010| Page o2503

doi:10.1107/S1600536810034847

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Ranunculin

Michael Benn,^a Lois Jean Yelland ^a and Masood Parvez ^a ^*

^aDepartment of Chemistry, The University of Calgary, 2500 University Drive NW, Calgary, Alberta, Canada T2N 1N4
^*Correspondence e-mail: parvez@ucalgary.ca

(Received 17 August 2010; accepted 29 August 2010; online 4 September 2010)

In the title molecule {systematic name: (5S)-5-[(β-D-glucopyranosyloxy)methyl]furan-2(5H)-one}, C₁₁H₁₆O₈, the five-membered ring is essentially planar, the maximum deviation being 0.0151 (13) Å for the O atom. The six-membered ring adopts a chair conformation with puckering parameters Q = 0.581 (2) Å, θ = 9.0 (2)° and φ = 39.7 (13)°, and with all of the substituents of the glucoside unit having normal equatorial orientations. The crystal structure is stabilized by extensive O—H⋯O and C—H⋯O hydrogen bonding, resulting in a three-dimensional network.

Related literature

For background to ranunculin, see: Hill & van Heyningen (1951 ); Bai et al. (1996 ); Benn & Yelland (1968 ); Boll (1968 ); Camps et al. (1982 ); Fang et al. (1989 ). For chemical and spectrometric data for closely related, simple butenolides, see: Perry et al. (1996 ). For comparison bond distances, see: Allen et al. (1987 ). For puckering parameters, see: Cremer & Pople (1975 ).

Experimental

Crystal data

C₁₁H₁₆O₈
M_r = 276.24
Monoclinic, P 2₁
a = 5.7944 (4) Å
b = 6.9359 (3) Å
c = 15.0491 (10) Å
β = 97.895 (2)°
V = 599.08 (6) Å³
Z = 2
Mo Kα radiation
μ = 0.13 mm⁻¹
T = 173 K
0.30 × 0.24 × 0.02 mm

Data collection

Nonius KappaCCD diffractometer with APEXII CCD
Absorption correction: multi-scan (SORTAV; Blessing, 1997 ) T_min = 0.961, T_max = 0.997
1926 measured reflections
1133 independent reflections
1112 reflections with I > 2σ(I)
R_int = 0.018

Refinement

R[F² > 2σ(F²)] = 0.026
wR(F²) = 0.069
S = 1.04
1133 reflections
184 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.18 e Å⁻³
Δρ_min = −0.16 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O5—H5O⋯O8ⁱ	0.86 (3)	2.17 (3)	2.910 (2)	144 (3)
O6—H6O⋯O5ⁱⁱ	0.92 (3)	1.94 (3)	2.824 (2)	162 (3)
O7—H7O⋯O6ⁱⁱ	0.84 (3)	1.84 (3)	2.668 (2)	173 (3)
O8—H8O⋯O2ⁱⁱⁱ	0.88 (3)	1.96 (3)	2.830 (2)	167 (3)
O6—H6O⋯O7	0.92 (3)	2.56 (3)	2.894 (2)	102 (2)
Symmetry codes: (i) x-1, y-1, z; (ii) $[-x, y+{\script{1\over 2}}, -z+1]$ ; (iii) $[-x+2, y+{\script{1\over 2}}, -z+2]$ .

Data collection: COLLECT (Hooft, 1998 ); cell refinement: DENZO (Otwinowski & Minor, 1997 ); data reduction: SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810034847/fl2315sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536810034847/fl2315Isup2.hkl

checkCIF report

Comment top

Ranunculin (I) is the glycosidic precursor of the vesicant protoanemonin present in numerous species of Rannunculaceae and is especially associated with the burning sensation on chewing leaves of buttercup plants. It was first obtained in crystalline form by Hill and van Heyningen (1951) who established its gross structure and showed that it undergoes enzymatic cleavage by β-glucosidase to yield the aglucone, which underwent easy dehydration to protoanemonin. These processes were shown to occur readily under autolytic conditions (Bai et al., 1996). The S-stereochemistry of the dihydrofuranone ring was deduced by Benn and Yelland (1968), and Boll (1968), as shown in the schematic diagram, and later confirmed by synthesis (Camps et al., 1982; Fang et al., 1989). Our sample of (I) was a natural product, and as such had been biosynthesised in the plant (and not made in a laboratory). The only stereoisomer which occurs naturally is the D-isomer, and both that and the anomeric configuration of the glycoosidic bond in (I) were established by cleavage of the glycoside by β-D-glucosidases. The X-ray structure reported here provides the simplest unequivocal proof of that stereochemistry since the chirality follows from that of the D-glucopyranosyl moiety.

The molecular structure of (I) is presented in Fig. 1. The five membered ring, O1/C2—C5, is essentially planar with the maximum deviation of any atom being 0.0151 (13) Å for O1. The six-membered ring adopts a chair conformation with puckering parameters (Cremer & Pople, 1975): Q = 0.581 (2) Å, θ = 9.0 (2)° and ϕ = 39.7 (13)°, with all of the substituents of the glucoside unit having normal equatorial orientations. The 5-membered ring folds back away from the six-membered ring as reflected by the torsion angle C6—O3—C1—C5 -162.86 (17)°. The bond distances and angles are as expected (Allen, 2002). The structure is stabilized by extensive O—H···O and C—H···O hydrogen bonding resulting in a three diemsional network (Table 1 & Fig. 2).

There are two other, closely related, simple butenolides known, though their structures rest on chemical and spectrometric data, i.e., without X-ray crystallographic support. They are the (5R,6R) and (5S,6R) steeroisomers of 5-([1-β-D-glucopyranosyloxy]ethyl)-2(5H)-furanone (Perry et al., 1996); the glycosidic precursor of (Z)-5-ethylidene-2(5H)-furanone, a homologue of protoanemonin in Halocarpus biformis juvenile foliage.

Related literature top

For background to ranunculin, see: Hill & van Heyningen (1951); Bai et al. (1996); Benn & Yelland (1968); Boll (1968); Camps et al. (1982); Fang et al. (1989). For chemical and spectrometric data for closely related, simple butenolides, see: Perry et al. (1996). For comparison of bond distances and angles, see: Allen et al. (1987). For puckering parameters, see: Cremer & Pople (1975).

Experimental top

The details of the isolation, and some of the physical properties, of our sample of (I) have been reported previously (Benn & Yelland 1968). Suitable crystals of the title compound for X-ray study were grown from a solution in aqueous ethanol (ca 1:20) in the form of plates.

Computing details top

Data collection: COLLECT (Hooft, 1998); cell refinement: DENZO (Otwinowski & Minor, 1997); data reduction: SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

	Fig. 1. ORTEP-3 (Farrugia, 1997) drawing of the title compound with displacement ellipsoids plotted at 50% probability level.
	Fig. 2. Unit cell packing of the title compound showing intermolecular hydrogen bonds of O—H···O; H-atoms not involved in hydrogen bonds have been excluded.

(5S)-5-[(β-D-glucopyranosyloxy)methyl]furan-2(5H)-one top

Crystal data top

C₁₁H₁₆O₈	F(000) = 292
M_r = 276.24	D_x = 1.531 Mg m⁻³
Monoclinic, P2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2yb	Cell parameters from 1560 reflections
a = 5.7944 (4) Å	θ = 1.0–30.0°
b = 6.9359 (3) Å	µ = 0.13 mm⁻¹
c = 15.0491 (10) Å	T = 173 K
β = 97.895 (2)°	Plate, colorless
V = 599.08 (6) Å³	0.30 × 0.24 × 0.02 mm
Z = 2

Data collection top

Nonius APEXII CCD [APEXII is a Bruker machine - is this a KappaCCD upgraded with an APEXII CCD?] diffractometer	1133 independent reflections
Radiation source: fine-focus sealed tube	1112 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.018
ϕ & ω scans	θ_max = 25.0°, θ_min = 3.2°
Absorption correction: multi-scan (SORTAV; Blessing, 1997)	h = −6→6
T_min = 0.961, T_max = 0.997	k = −6→8
1926 measured reflections	l = −17→17

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)] = 0.026	Hydrogen site location: difference Fourier map
wR(F²) = 0.069	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	w = 1/[σ²(F_o²) + (0.040P)² + 0.1617P] where P = (F_o² + 2F_c²)/3
1133 reflections	(Δ/σ)_max = 0.002
184 parameters	Δρ_max = 0.18 e Å⁻³
1 restraint	Δρ_min = −0.16 e Å⁻³

Crystal data top

C₁₁H₁₆O₈	V = 599.08 (6) Å³
M_r = 276.24	Z = 2
Monoclinic, P2₁	Mo Kα radiation
a = 5.7944 (4) Å	µ = 0.13 mm⁻¹
b = 6.9359 (3) Å	T = 173 K
c = 15.0491 (10) Å	0.30 × 0.24 × 0.02 mm
β = 97.895 (2)°

Data collection top

Nonius APEXII CCD [APEXII is a Bruker machine - is this a KappaCCD upgraded with an APEXII CCD?] diffractometer	1133 independent reflections
Absorption correction: multi-scan (SORTAV; Blessing, 1997)	1112 reflections with I > 2σ(I)
T_min = 0.961, T_max = 0.997	R_int = 0.018
1926 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.026	1 restraint
wR(F²) = 0.069	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	Δρ_max = 0.18 e Å⁻³
1133 reflections	Δρ_min = −0.16 e Å⁻³
184 parameters

Special details top

Experimental. NMR data (400 MHz, ¹H; 100 MHz ¹³C) for a solution in D₂O containing sodium 3-trimethylsilylpropionate-2,3 - d₄ as reference: δ_H (400 MHz) 7.77 (1H, dd, J = 1.5 and 5.8 Hz, H-4), 6.3 (1H, dd, J = 2.1 and 5.8 Hz, H-3), 5.47 (1H, m), 4.48 (1H, d, J = 7.9 Hz, H-1'), 4.30 (1H, dd, J = 3.2 and 12.2 Hz, H-6 A), 3.95 (1H, dd, J = 5.8 and 12.2 Hz, H-6B), 3.91 (1H, dd, J = 2.1 and 12.5 Hz, H-6A'), 3.72 (1H, dd, J = 5.8 and 12.5 Hz, H-6B'), 3.48 (1H, dd, dd, J = ca 9 Hz H-3'), 3.43 (1H, m, H-5'), 3.37 (1H, dd, J = ca 9 Hz, H=4'), and 3.25 (1H, dd, J = 7.9 and 9.2 Hz, H-2'); δ_C 179.2 s (C-2), 158.5 d (C-4), 124.7 d (C-3), 105.6 d (C-1'), 86.9 d (C-5), 78.7 d (C-5'), 78.3 d (C-3'), 75.6 d (C-2'), 72.2 d (C-4'), 71.7 t (C-6), 63.3 t (C-6').

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
O1	0.9146 (3)	−0.1112 (2)	0.96815 (9)	0.0225 (4)
O2	1.0618 (3)	−0.0493 (3)	1.11025 (10)	0.0309 (4)
O3	0.4499 (2)	0.0377 (2)	0.79524 (9)	0.0200 (3)
O4	0.5209 (2)	0.3269 (2)	0.73224 (9)	0.0188 (3)
O5	0.1227 (3)	−0.0568 (2)	0.63887 (10)	0.0241 (4)
H5O	0.085 (5)	−0.121 (5)	0.6833 (19)	0.036*
O6	−0.0241 (2)	0.2692 (2)	0.53178 (10)	0.0208 (4)
H6O	−0.025 (5)	0.336 (5)	0.479 (2)	0.031*
O7	0.3667 (3)	0.5126 (3)	0.50561 (9)	0.0215 (3)
H7O	0.259 (5)	0.591 (5)	0.4895 (18)	0.032*
O8	0.8805 (3)	0.6376 (3)	0.72096 (10)	0.0277 (4)
H8O	0.893 (5)	0.563 (5)	0.769 (2)	0.042*
C1	0.6798 (3)	0.0332 (4)	0.84401 (13)	0.0216 (5)
H1A	0.7191	0.1601	0.8721	0.026*
H1B	0.7947	0.0036	0.8030	0.026*
C2	0.8918 (4)	−0.0724 (3)	1.05518 (13)	0.0225 (5)
C3	0.6434 (4)	−0.0666 (4)	1.06406 (14)	0.0252 (5)
H3	0.5794	−0.0486	1.1183	0.030*
C4	0.5229 (4)	−0.0912 (3)	0.98301 (14)	0.0243 (5)
H4	0.3578	−0.0895	0.9699	0.029*
C5	0.6862 (4)	−0.1216 (3)	0.91570 (13)	0.0204 (5)
H5	0.6609	−0.2517	0.8874	0.025*
C6	0.4469 (4)	0.1343 (3)	0.71336 (13)	0.0178 (4)
H6	0.5552	0.0694	0.6765	0.021*
C7	0.2004 (3)	0.1338 (3)	0.66293 (13)	0.0176 (4)
H7	0.0906	0.1980	0.6994	0.021*
C8	0.2093 (3)	0.2433 (3)	0.57590 (13)	0.0167 (4)
H8	0.2985	0.1652	0.5363	0.020*
C9	0.3238 (3)	0.4413 (3)	0.59065 (13)	0.0172 (4)
H9	0.2164	0.5310	0.6170	0.021*
C10	0.5559 (3)	0.4305 (3)	0.65204 (13)	0.0180 (4)
H10	0.6738	0.3622	0.6208	0.022*
C11	0.6423 (4)	0.6302 (3)	0.67948 (14)	0.0218 (5)
H11A	0.6248	0.7137	0.6256	0.026*
H11B	0.5424	0.6840	0.7217	0.026*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0203 (7)	0.0294 (9)	0.0169 (7)	0.0038 (6)	−0.0002 (5)	0.0024 (6)
O2	0.0327 (8)	0.0329 (10)	0.0233 (8)	0.0036 (8)	−0.0095 (7)	−0.0014 (8)
O3	0.0212 (7)	0.0242 (8)	0.0137 (7)	−0.0011 (7)	−0.0005 (5)	0.0038 (6)
O4	0.0226 (7)	0.0190 (8)	0.0143 (7)	−0.0026 (6)	0.0005 (5)	−0.0001 (6)
O5	0.0317 (8)	0.0223 (8)	0.0172 (7)	−0.0077 (7)	−0.0007 (6)	0.0020 (7)
O6	0.0177 (7)	0.0259 (8)	0.0174 (7)	−0.0007 (6)	−0.0027 (6)	0.0030 (7)
O7	0.0218 (7)	0.0257 (8)	0.0172 (7)	0.0016 (7)	0.0036 (6)	0.0063 (7)
O8	0.0262 (8)	0.0330 (9)	0.0227 (8)	−0.0102 (8)	−0.0010 (6)	0.0034 (8)
C1	0.0200 (10)	0.0262 (12)	0.0175 (10)	−0.0020 (10)	−0.0010 (8)	0.0041 (9)
C2	0.0302 (11)	0.0188 (10)	0.0175 (9)	0.0063 (10)	0.0000 (9)	0.0026 (9)
C3	0.0306 (11)	0.0257 (11)	0.0201 (10)	0.0037 (10)	0.0064 (8)	0.0025 (10)
C4	0.0235 (10)	0.0234 (12)	0.0264 (12)	0.0004 (10)	0.0044 (9)	0.0071 (10)
C5	0.0217 (10)	0.0214 (11)	0.0168 (10)	−0.0001 (9)	−0.0023 (8)	0.0016 (9)
C6	0.0216 (10)	0.0179 (10)	0.0138 (9)	−0.0003 (9)	0.0020 (7)	0.0016 (9)
C7	0.0190 (10)	0.0188 (10)	0.0151 (9)	−0.0014 (9)	0.0025 (7)	0.0003 (9)
C8	0.0152 (10)	0.0207 (10)	0.0135 (9)	0.0003 (9)	−0.0001 (8)	−0.0008 (8)
C9	0.0185 (10)	0.0191 (10)	0.0143 (9)	0.0010 (9)	0.0038 (7)	0.0010 (9)
C10	0.0180 (10)	0.0216 (10)	0.0147 (9)	−0.0004 (10)	0.0038 (8)	0.0017 (9)
C11	0.0253 (11)	0.0206 (11)	0.0189 (10)	−0.0016 (9)	0.0004 (8)	0.0006 (10)

Geometric parameters (Å, º) top

O1—C2	1.361 (2)	C2—C3	1.464 (3)
O1—C5	1.447 (2)	C3—C4	1.331 (3)
O2—C2	1.208 (3)	C3—H3	0.9500
O3—C6	1.401 (2)	C4—C5	1.493 (3)
O3—C1	1.430 (2)	C4—H4	0.9500
O4—C6	1.419 (3)	C5—H5	1.0000
O4—C10	1.443 (2)	C6—C7	1.523 (3)
O5—C7	1.427 (3)	C6—H6	1.0000
O5—H5O	0.86 (3)	C7—C8	1.521 (3)
O6—C8	1.434 (2)	C7—H7	1.0000
O6—H6O	0.92 (3)	C8—C9	1.528 (3)
O7—C9	1.425 (2)	C8—H8	1.0000
O7—H7O	0.84 (3)	C9—C10	1.525 (2)
O8—C11	1.435 (3)	C9—H9	1.0000
O8—H8O	0.88 (3)	C10—C11	1.511 (3)
C1—C5	1.519 (3)	C10—H10	1.0000
C1—H1A	0.9900	C11—H11A	0.9900
C1—H1B	0.9900	C11—H11B	0.9900

C2—O1—C5	109.40 (15)	O4—C6—H6	109.9
C6—O3—C1	111.09 (15)	C7—C6—H6	109.9
C6—O4—C10	112.00 (15)	O5—C7—C8	106.92 (16)
C7—O5—H5O	113 (2)	O5—C7—C6	111.72 (17)
C8—O6—H6O	110.7 (18)	C8—C7—C6	106.69 (16)
C9—O7—H7O	105.7 (19)	O5—C7—H7	110.5
C11—O8—H8O	107 (2)	C8—C7—H7	110.5
O3—C1—C5	108.08 (17)	C6—C7—H7	110.5
O3—C1—H1A	110.1	O6—C8—C7	108.63 (16)
C5—C1—H1A	110.1	O6—C8—C9	108.56 (17)
O3—C1—H1B	110.1	C7—C8—C9	112.90 (16)
C5—C1—H1B	110.1	O6—C8—H8	108.9
H1A—C1—H1B	108.4	C7—C8—H8	108.9
O2—C2—O1	120.56 (19)	C9—C8—H8	108.9
O2—C2—C3	130.8 (2)	O7—C9—C10	108.24 (15)
O1—C2—C3	108.66 (17)	O7—C9—C8	107.89 (16)
C4—C3—C2	108.1 (2)	C10—C9—C8	111.93 (17)
C4—C3—H3	125.9	O7—C9—H9	109.6
C2—C3—H3	125.9	C10—C9—H9	109.6
C3—C4—C5	109.8 (2)	C8—C9—H9	109.6
C3—C4—H4	125.1	O4—C10—C11	107.91 (16)
C5—C4—H4	125.1	O4—C10—C9	108.49 (15)
O1—C5—C4	103.91 (16)	C11—C10—C9	110.63 (17)
O1—C5—C1	106.48 (16)	O4—C10—H10	109.9
C4—C5—C1	115.19 (19)	C11—C10—H10	109.9
O1—C5—H5	110.3	C9—C10—H10	109.9
C4—C5—H5	110.3	O8—C11—C10	114.47 (18)
C1—C5—H5	110.3	O8—C11—H11A	108.6
O3—C6—O4	107.90 (15)	C10—C11—H11A	108.6
O3—C6—C7	109.54 (16)	O8—C11—H11B	108.6
O4—C6—C7	109.80 (16)	C10—C11—H11B	108.6
O3—C6—H6	109.9	H11A—C11—H11B	107.6

C6—O3—C1—C5	−162.86 (17)	O3—C6—C7—C8	179.11 (17)
C5—O1—C2—O2	−176.8 (2)	O4—C6—C7—C8	60.8 (2)
C5—O1—C2—C3	3.2 (2)	O5—C7—C8—O6	68.0 (2)
O2—C2—C3—C4	176.8 (3)	C6—C7—C8—O6	−172.30 (16)
O1—C2—C3—C4	−3.3 (3)	O5—C7—C8—C9	−171.50 (16)
C2—C3—C4—C5	2.0 (3)	C6—C7—C8—C9	−51.8 (2)
C2—O1—C5—C4	−2.0 (2)	O6—C8—C9—O7	−71.42 (19)
C2—O1—C5—C1	120.06 (19)	C7—C8—C9—O7	168.07 (16)
C3—C4—C5—O1	−0.1 (3)	O6—C8—C9—C10	169.60 (14)
C3—C4—C5—C1	−116.2 (2)	C7—C8—C9—C10	49.1 (2)
O3—C1—C5—O1	−175.41 (16)	C6—O4—C10—C11	−177.97 (16)
O3—C1—C5—C4	−60.8 (2)	C6—O4—C10—C9	62.1 (2)
C1—O3—C6—O4	−61.2 (2)	O7—C9—C10—O4	−169.84 (18)
C1—O3—C6—C7	179.26 (17)	C8—C9—C10—O4	−51.1 (2)
C10—O4—C6—O3	171.64 (15)	O7—C9—C10—C11	72.0 (2)
C10—O4—C6—C7	−69.02 (19)	C8—C9—C10—C11	−169.25 (17)
O3—C6—C7—O5	−64.4 (2)	O4—C10—C11—O8	74.2 (2)
O4—C6—C7—O5	177.31 (17)	C9—C10—C11—O8	−167.27 (16)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O5—H5O···O8ⁱ	0.86 (3)	2.17 (3)	2.910 (2)	144 (3)
O6—H6O···O5ⁱⁱ	0.92 (3)	1.94 (3)	2.824 (2)	162 (3)
O7—H7O···O6ⁱⁱ	0.84 (3)	1.84 (3)	2.668 (2)	173 (3)
O8—H8O···O2ⁱⁱⁱ	0.88 (3)	1.96 (3)	2.830 (2)	167 (3)
C3—H3···O4^iv	0.95	2.55	3.413 (3)	151
C4—H4···O1^v	0.95	2.57	3.504 (3)	168
C8—H8···O7^vi	1.00	2.37	3.306 (3)	155
C1—H1A···O2ⁱⁱⁱ	0.99	2.38	3.289 (3)	153
C10—H10···O6^vii	1.00	2.43	3.415 (3)	167
O6—H6O···O7	0.92 (3)	2.56 (3)	2.894 (2)	102 (2)
C11—H11A···O7	0.99	2.59	2.986 (3)	104

Symmetry codes: (i) x−1, y−1, z; (ii) −x, y+1/2, −z+1; (iii) −x+2, y+1/2, −z+2; (iv) −x+1, y−1/2, −z+2; (v) x−1, y, z; (vi) −x+1, y−1/2, −z+1; (vii) x+1, y, z.

Experimental details

Crystal data
Chemical formula	C₁₁H₁₆O₈
M_r	276.24
Crystal system, space group	Monoclinic, P2₁
Temperature (K)	173
a, b, c (Å)	5.7944 (4), 6.9359 (3), 15.0491 (10)
β (°)	97.895 (2)
V (Å³)	599.08 (6)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.13
Crystal size (mm)	0.30 × 0.24 × 0.02

Data collection
Diffractometer	Nonius APEXII CCD [APEXII is a Bruker machine - is this a KappaCCD upgraded with an APEXII CCD?] diffractometer
Absorption correction	Multi-scan (SORTAV; Blessing, 1997)
T_min, T_max	0.961, 0.997
No. of measured, independent and observed [I > 2σ(I)] reflections	1926, 1133, 1112
R_int	0.018
(sin θ/λ)_max (Å⁻¹)	0.595

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.026, 0.069, 1.04
No. of reflections	1133
No. of parameters	184
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)	0.18, −0.16

Computer programs: COLLECT (Hooft, 1998), DENZO (Otwinowski & Minor, 1997), SCALEPACK (Otwinowski & Minor, 1997), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O5—H5O···O8ⁱ	0.86 (3)	2.17 (3)	2.910 (2)	144 (3)
O6—H6O···O5ⁱⁱ	0.92 (3)	1.94 (3)	2.824 (2)	162 (3)
O7—H7O···O6ⁱⁱ	0.84 (3)	1.84 (3)	2.668 (2)	173 (3)
O8—H8O···O2ⁱⁱⁱ	0.88 (3)	1.96 (3)	2.830 (2)	167 (3)
O6—H6O···O7	0.92 (3)	2.56 (3)	2.894 (2)	102 (2)

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

References

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