Zwitterionic and free forms of aryl­methyl Meldrum's acids

C-Alkyl (including C-aryl­meth­yl) derivatives of Meldrum's acids are attractive building blocks in organic synthesis, mainly due to the unusually high acidity of the resulting compounds. Three examples, namely 5-[4-(di­ethyl­amino)­benz­yl]-2,2-dimethyl-1,3-dioxane-4,6-dione, C₁₇H₂₃NO₄, (I), 2,2-dimethyl-5-(2,4,6-tri­meth­oxy­benz­yl)-1,3-dioxane-4,6-dione, C₁₆H₂₀O₇, (II), and 5-(4-hy­droxy-3,5-di­meth­oxy­benz­yl)-2,2-dimethyl-1,3-dioxane-4,6-dione, C₁₅H₁₈O₇, (III), have been synthesized, characterized by NMR and IR spectroscopy, and studied by single-crystal X-ray structure analysis. The nature of the different substituents resulted in remarkable differences in both the mol­ecular conformations and the crystal packing arrangements. The presence of a substituent with a basic centre in compound (I) leads to the formation of an inner salt accompanied by drastic changes in the conformation of the 1,3-dioxane-4,6-dione fragment. By virtue of strong N—H...O hydrogen bonds, the residues are assembled into infinite chains with the graph-set descriptor C(10). Compound (II) contains meth­oxy groups in both the ortho- and para-positions of the aryl­methyl fragment. Because of the absence of classical hydrogen-bond donors in this structure, the crystal packing is controlled by van der Waals forces and weak C—H...O inter­actions. Compound (III) contains meth­oxy groups in both meta-positions and a hy­droxy group in the para-position. Supra­molecular tetra­meric synthons which comprise hydrogen-bonded dimers associated into tetra­mers through π–π inter­actions of overlapping benzene rings were observed.

S1. Introduction

C-Alkyl (including C-aryl­methyl) derivatives of Meldrum's acids are attractive building blocks in organic synthesis (Mierina, 2013) that is mainly due to the unusually high acidity of the resulting compounds (Nakamura et al., 2004; Byun et al., 2001). Aryl­methyl Meldrum's acids show good and excellent anti­radical and anti­oxidant properties (Mierina et al., 2014) also. Despite the wide-ranging applications of these compounds, the crystal structure of this type of Meldrum's acids derivatives is poorly studied. A search of the Cambridge Structural Database (Groom & Allen, 2014) revealed only one aryl­methyl Meldrum's acid, namely 5-(2,3-di­meth­oxy­benzyl)-2,2-di­methyl-1,3-dioxane-4,6-dione (CSD refcode FONZOY; reference?), studied by a single-crystal X-ray diffraction. Only a few studies have been devoted to the determination of intra­molecular inter­actions into aryl­methyl Meldrum's acids. Anomalous deshielding in ¹H NMR spectra were observed for the α-H atom in the di­carbonyl fragment for compounds containing different hydrogen-bond acceptors in the ortho-position of the benzene ring in comparison with derivatives of Meldrum's acids without a hydrogen-bond acceptor at the same position. The effect was even more pronounced when an additional substituent was introduced at the benzylic position. Moreover, in the crystalline state, strong intra­molecular hydrogen bonding was observed also (Fillion et al., 2009). The aim of this work was to gain more knowledge on the conformations, the intra- and mainly inter­molecular contacts (hydrogen bonds, van der Waals and π–π inter­actions) in 5-aryl­methyl-2,2-di­methyl-1,3-dioxane-4,6-diones in the crystalline state depending on different substituents. In order to find out whether these inter­actions in crystals of Meldrum's acid derivatives are general or unique, three structures of aryl­methyl Meldrum's acids were analyzed, namely 5-[4-(di­ethyl­amino)­benzyl]-2,2-di­methyl-1,3-dioxane-4,6-dione, (I), 2,2-di­methyl-5-(2,4,6-tri­meth­oxy­benzyl)-1,3-dioxane-4,6-dione, (II), 5-(4-hy­droxy-3,5-di­meth­oxy­benzyl)-2,2-di­methyl-1,3-dioxane-4,6-dione, (III).

S2. Experimental

¹H (300 MHz) and ¹³C (75.5 MHz) NMR spectra were recorded on Bruker Avance 300 spectrometer; the samples were dissolved in CDCl₃-d and the spectra were calibrated to the residue of CHCl₃. IR spectra were recorded on Perkin–Elmer spectrometer (model: Spectrum BX, FT—IR system) for solid sample in KBr disc. Melting points were measured with a STUART melting point SMP10 apparatus and are uncorrected. Microanalysis was done with Carlo–Erba Instruments element analyzer (model: EA1108). High resolution mass spectra were recorded on Agilent 1290 Infinity series UPLC chromatograph equipped with Agilent 6230 TOF LC/MS mass spectrometer. Meldrum's acid, aromatic aldehydes, NaBH₄, acetic acid and solvents were commercially available and were used without further purification.

S2.1. Synthesis and crystallization

\ Aryl­methyl Meldrum's acids (I)–(III) were synthesized according to a known method (Frost et al., 2009) with some modifications from Meldrum's acid (IV) and aromatic aldehyde, followed by reduction of the obtained 5-aryl­idene-1,3-dioxane-4,6-dione, (V)–(VII), with NaBH₄ (see Scheme 1).

5-[(4-Hy­droxy-3,5-di­meth­oxy­phenyl)­methyl­ene]-2,2-di­methyl-1,3-dioxane-4,6-\ dione, (VII), is a known compound (Le et al., 2013) and was used without further purification.

S2.1.1. General synthesis of 5-aryl­methyl-2,2-di­methyl-1,3-dioxane-4,6-diones (I)–(III)

The syntheses were carried out according to a modification of the method of Frost et al. (2009). Aryl­idene Meldrum's acids (V)–(VII) (12 mmol) were dissolved in chloro­form (50 ml) and the solutions cooled to 270–273 K (ice bath), followed by addition of glacial acetic acid (5.7 ml). NaBH₄ (0.53 g) was added portionwise after 5 min and the mixtures were further mixed for approximately 45 min until the colour of the solutions disappeared. The reactions were quenched with water (50 ml). The organic layers were separated and the water solutions extracted with chloro­form (50 ml). For each preparation, all chloro­form extracts were combined and washed with brine (2 × 75 ml) and water (2 × 75 ml). The chloro­form extracts were dried over Na₂SO₄, evaporated and recrystallized from ethanol. Single crystals of (I)–(III) suitable for X-ray analysis were obtained from solutions in methanol.

S2.1.2. General synthesis of 5-aryl­idene-1,3-dioxane-4,6-diones (V)–(VII)

The syntheses were carried out according to the previously described method of Bigi et al. (2001). In brief, 2,2-di­methyl-1,3-dioxane-4,6-dione, (IV) (1 g, 6.9 mmol), an aromatic aldehyde (6.9 mmol) and water (50 ml) were heated at 348 K for 2 h, followed with cooling to room temperature and filtration of the resulted precipitates. The solid material was air-dried in each case and recrystalized from ethanol.

S2.2. Spectroscopic and analytical data

S2.2.1. 5-[4-(Di­ethyl­amino)­benzyl]-2,2-di­methyl-1,3-dioxane-4,6-dione, (I)

The compound appeared as white solid (yield 35%, m.p. 411-412 K). IR (KBr) ν (cm^-1): 3690, 2995, 2940, 2900, 2450, 2360, 2340, 1675, 1605, 1565, 1515, 1475, 1385, 1365, 1345, 1295, 1255, 1210, 1195, 1110, 1100, 1035, 1020, 990, 960, 925, 825, 810, 795, 745, 730, 690, 645, 620, 550, 525, 520, 425; ¹H NMR (300 MHz, CDCl₃): δ 1.14 [6H, t, J = 7.1 Hz, N(CH₂CH₃)₂], 1.45 (3H, s, Me), 1.73 (3H, s, Me), 3.3 [4H, q, J = 7.1 Hz, N(CH₂CH₃)₂], 3.41 (2H, d, J = 4.7 Hz, CH₂), 3.72 (1H, t, J = 4.7 Hz, CH), 6.61 (2H, d, J = 8.5 Hz, 2 × C^ArH), 7.17 (2H, d, J = 8.5 Hz, 2 × C^ArH); ¹³C NMR (75.5 MHz, CDCl₃): δ 12.6 [N(CH₂CH₃)₂], 27.5 (Me), 28.5 (Me), 31.7 (CH₂), 44.4 [N(CH₂CH₃)₂], 48.6 (CH), 105.2 (CMe₂), 112.0 (2 × C^ArH), 123.6 (C^ArCH₂), 130.9 (2 × C^ArH), 146.9 (C^ArNEt₂), 165.8 (COOR). Analysis calculated for C₁₇H₂₃NO₄: C 66.86, H 7.59, N 4.59%; found: C 66.53, H 7.70, N 4.38%.

S2.2.2. 2,2-Di­methyl-5-(2,4,6-tri­meth­oxy­benzyl)-1,3-dioxane-4,6-dione, (II)

The compound appeared as white solid (yield 55%, m.p. 416–417 K). IR (KBr) ν (cm^-1): 3680, 3010, 2980, 2950, 2910, 2865, 2840, 1780, 1750, 1610, 1600, 1505, 1465, 1420, 1395, 1390, 1375, 1335, 1265, 1235, 1215, 1205, 1155, 1120, 1085, 1075, 1035, 1025, 990, 955, 945, 925, 865, 835, 795, 750, 740, 705, 630, 545, 490, 420; ¹H NMR (300 MHz, CDCl₃): δ 1.75 (3H, s, Me), 1.82 (3H, s, Me), 3.37 (2H, d, J = 7.3 Hz, CH₂), 3.79 (9H, s, 3 × OMe), 3.92 (1H, t, J = 7.3 Hz, CH), 6.12 (2H, s, 2 × C^ArH); ¹³C NMR (75.5 MHz, CDCl₃): δ 22.8 (CH₂), 27.7 (Me), 28.7 (Me), 45.0 (CH), 55.4 (OMe), 55.7 (2 × OMe), 90.7 (2 × C^ArH), 105.1 (CMe₂/C^ArCH₂), 105.2 (CMe₂/C^ArCH₂), 159.0 (2 × C^ArOMe), 160.4 (C^ArOMe), 165.8 (COOR). Analysis calculated for C₁₆H₂₀O₇: C 59.22, H 6.22%; found: C 59.20, H 6.20%.

S2.2.3. 5-(4-hy­droxy-3,5-di­meth­oxy­benzyl)-2,2-di­methyl-1,3-dioxane-4,6-dione, (III)

The compound appeared as white solid (yield 36%, m.p. 398 K). IR (KBr) ν (cm^-1): 3560, 3500, 2995, 2955, 2940, 2875, 2840, 1785, 1750, 1615, 1520, 1460, 1420, 1995, 1385, 1350, 1310, 1265, 1245, 1215, 1195, 1115, 1055, 1020, 1000, 970, 950, 905, 885, 865, 850, 835, 810, 690, 670, 645, 635, 620, 585, 490, 455; ¹H NMR (300 MHz, CDCl₃): δ 1.47 (3H, s, Me), 1.72 (3H, s, Me), 3.42 (2H, d, J = 4.6 Hz, CH₂), 3.72 (1H, t, J = 4.6 Hz, CH), 3.85 (6H, s, 2 × OMe), 5.48 (1H, brs, OH), 6.55 (2H, s, 2 × C^ArH); ¹³C NMR (75.5 MHz, CDCl₃): δ 27.6 (Me), 28.7 (Me), 32.6 (CH₂), 48.6 (CH), 56.5 (OMe), 105.4 (CMe₂), 106.7 (2 × C^ArH), 128.2 (C^ArCH₂), 133.9 (C^ArOH), 147.0 (2 × C^ArOMe), 165.7 (COOR). Analysis calculated for [M + Na]⁺ m/z: 333.0950; found m/z: 333.0942.

S2.2.4. 5-[(4-Di­ethyl­amino­phenyl)­methyl­ene]-2,2-di­methyl-1,3-dioxane-4,6-dione, (V)

This compound is known [m.p. 398 K; literature 397–398 K (Strods et al., 1978)]. Nevertheless, NMR spectral data have not been provided previously. ¹H NMR (300 MHz, CDCl₃): δ 1.21 [6H, t, J = 7.1 Hz, N(CH₂CH₃)₂], 1.75 (6H, s, 2 × Me), 3.46 [4H, q, J = 7.1 Hz, N(CH₂CH₃)₂], 6.65 (2H, d, J = 9.3 Hz, 2 × C^ArH), 8.21 (2H, d, J = 9.3 Hz, 2 × C^ArH), 8.24 (1H, s, CH); ¹³C NMR (75.5 MHz, CDCl₃): δ 12.7 [N(CH₂CH₃)₂], 27.3 (2 × Me), 45.0 [N(CH₂CH₃)₂], 103.4 (CMe₂), 104.2 (C═CH), 111.1 (2 × C^ArH), 119.8 (C^ArCH), 139.4 (2 × C^ArH), 152.8 (C^ArNEt₂), 157.8 (CH), 161.6 (COOR), 165.4 (COOR).

S2.2.5. 5-[(2,4,6-trimetoxyphenyl)­methyl­ene]-2,2-di­methyl-1,3-dioxane-4,6-dione, (VI)

The compound appeared as bright-yellow solid (yield 78%; m.p. 487 K). IR (KBr) ν (cm^-1): 1750, 1725, 1595, 1570, 1495, 1470, 1450, 1395, 1385, 1365, 1335, 1285, 1230, 1205, 1190, 1155, 1140, 1110, 1030, 1005, 940, 905, 825, 785, 725, 490, 430; ¹H NMR (300 MHz, CDCl₃): δ 1.84 (6H, s, 2 × Me), 3.85 (6H, s, 2 × OMe), 3.88 (3H, s, OMe), 6.11 (2H, s, 2 × C^ArH), 8.49 (1H, s, CH); ¹³C NMR (75.5 MHz, CDCl₃): δ 27.4 (2 × Me), 55.7 (OMe), 55.8 (2 × OMe), 90.8 (2 × C^ArH), 104.2 (CMe₂), 106.1 (C^ArCH), 114.6 (C═CH), 147.8 (CH), 161.1 (2 × C^ArOMe), 161.2 (C^ArOMe), 163.7 (COOR), 165.9 (COOR). Analysis calculated for [M + Na]⁺ m/z: 345.0945; found m/z: 345.0945.

S2.3. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1.

In (I), the position of the transferred H atom was located from a difference electron-density map and was refined in a least-squares full-matrix isotropic approximation.

S3. Results and discussion

The molecular structure of (I)–(III), with the atom-numbering schemes, are shown in Figs. 1, 2 and 3, respectively. The packing diagrams showing supra­molecular features of the structures are presented in Figs. 4, 5 and 6, respectively. In the crystal, 5-[4-(di­ethyl­amino)­benzyl]-2,2-di­methyl-1,3-dioxane-4,6-dione, (I), exists in the zwitterionic form. The sum of the valence angles at the C5 atom is 359.1 (3)°; thus it is in the sp² hybridization state. An analysis of the bond lengths in the di­carbonyl fragment shows differentiation of single [C5—C6 = 1.411 (2) Å and C4—O2 = 1.252 (2) Å] and double bonds [C4—C5 = 1.384 (2) Å and C6—O19 = 1.229 (2) Å], suggesting the formation of the enolate structure. The absorption band in the IR spectrum at 1675 cm^-1 is consistent with the existence of the enolate form. The H atom on O20 is transferred to atom N16 forming the zwitterionic structure of the residue. The heterocycle assumes a distorted boat conformation. Atoms C2 and C5 deviate from the least-squares plane [±0.006 (1) Å] calculated for the other four atoms in the heterocycle by 0.517 (2) and 0.074 (2) Å, respectively. The corresponding dihedral angles between the plane bottom of the boat and the triangles formed by atoms C2/O1/O3 and C4–C6 are 39.4 (2) and 6.1 (2)°, respectively. The total puckering amplitude for the heterocycle is 0.389 (2) Å. This is the first example where an anilinium-type zwitterionic form of Meldrum's acid is described and the inner ions are linked with the aryl­methyl moiety. Whereas, until now, the crystal structures of inner salts have been established only for di­methyl­amino­methyl Meldrum's acid (Li et al., 2005) and a pyridin-1-yl derivative of Meldrum's acid (Zia-Ebrahimi et al., 1994), where the distance between the ammonium ion and the deprotonated enalizated malonate moiety is remarkably shorter – just CH₂ functionality. In the crystal, the residues are assembled by means of strong N—H···O hydrogen bonds into infinite chains with the graph set C(10) along the unit-cell a axis (Fig. 2).

As we have already mentioned in the Introduction, the ability of the acidic C—H bond to form an intra­molecular C—H···X (X = O, S, F) bonds in benzyl Meldrum's acids has been investigated by Fillion et al. (2009), and it was concluded that an intra­molecular C5—H···O hydrogen bond is able to drive the conformational properties of aryl­methyl Meldrum's acids in the solid state. In this respect, it was inter­esting to find out whether 2,2-di­methyl-5-(2,4,6-tri­meth­oxy­benzyl)-1,3-dioxane-4,6-dione, (II), which contains meth­oxy groups in both ortho-positions of the benzyl fragment, assumes the conformation with an intra­molecular C5—H···O hydrogen bond. It turned out that this kind of hydrogen bond is not present in the crystal structure of (II). In the molecule, the aryl­methyl fragment is rotated in the opposite direction to the acidic C5—H bond. The conformation of this type of Meldrum's acids is well described by the torsion angles H—C5—C7—C8 and C5—C7—C8—C9 (Table 2). The planar 2,4,6-tri­meth­oxy­phenyl fragment is almost perpendicular to the average plane of the six-membered heterocycle of the Meldrum's acid. The 1,3-dioxane moiety adopts a boat conformation. Atoms C2 and C5 deviate from the mean plane [±0.008 (1) Å] formed by the other four atoms in the heterocycle by 0.502 (2) and 0.383 (2) Å. The corresponding dihedral angles between the bottom of the boat and the triangles formed by atoms C2/O1/O3 and C4–C6 are 37.3 (1) and 27.2 (2)°, respectively. The puckering amplitude Q for the heterocycle is 0.515 (2) Å. Compound (II) has no classical hydrogen-bond donors and acceptors. Its packing in the crystal is governed, mainly, by van der Waals inter­actions. Two short contacts (Table 3) can be attributed to C—H···O type hydrogen bonds. Fig. 4 shows a fragment of the crystal packing for the structure of (II). Thus, one can conclude that the presence of a hydrogen-bond acceptor in the ortho-position of the aryl­methyl fragment does not guarantee the formation of a C5—H···O intra­molecular bond and the molecular conformation is dependent on the overall balance of the free energy of the crystal lattice.

The crystal structure of 5-(4-hy­droxy-3,5-di­meth­oxy­benzyl)-2,2-di­methyl-1,3-dioxane-4,6-dione, (III), contains two independent molecules (A and B) in the asymmetric unit. The molecules differ in their conformations defined, mainly, by the torsion angles along the C5—C7 and C7—C8 bonds (Table 2). The dihedral angles between the least-squares mean planes of the heterocycle and benzene rings in the molecules A and B are 41.8 (1) and 55.1 (1)°, respectively. In both molecules, the Meldrum's acid heterocycles assume the boat conformation. Atoms C2 and C5 deviate from the mean planes formed by the other four atoms of the rings in molecules A and B by 0.441 (2)/0.477 (2) and 0.476 (3)/0.469 (2) Å, respectively. The corresponding dihedral angles between the bottom of the boat and the triangles formed by atoms C2/O1/O3 and C4–C6 for molecules A and B are 32.3 (2)/33.4 (2) and 35.0 (2)/33.5 (2)°, respectively. The corresponding values of the puckering amplitude Q for the heterocycle in molecules A and B are 0.533 (2) and 0.546 (2) Å, respectively. Molecules A and B form dimers by means of hydrogen bonds of the O—H···O type (Table 3). The dimers are associated into a tetra­meric synthon through π–π inter­actions of the partially overlapping aryl rings of molecules A and B (Fig. 6). The distance between the centroids is 3.678 Å. The hy­droxy groups are also involved in intra­molecular hydrogen bonds with the O atoms of adjacent meth­oxy groups. There are also intra­molecular C—H···O inter­actions in the structure. Their geometrical parameters are given in the Table 3.

Despite the high structural similarity of studied aryl­methyl Meldrum's acids, the nature of different substituents resulted in remarkable differences in both the molecular conformations and the crystal packing arrangements. The presence of a substituent with a basic centre in compound (I) leads to the formation of an inner salt accompanied by drastic changes in the conformation of the 1,3-dioxane-4,6-dione fragment. By virtue of strong hydrogen bonds of the N—H···O type, the residues are assembled into infinite chains with the graph-set C(10). Compound (II) contains meth­oxy groups in both the ortho- and para-positions of the aryl­methyl fragment. Hypothetically, one could expect the formation of an intra­molecular C5—H···O hydrogen bond. However, in the crystal, this hydrogen bond was not observed. Because of the absence of classical hydrogen-bond donors in this structure, the crystal packing is controled by the van der Waals forces and weak C—H···O inter­actions. Compound (III) contains meth­oxy groups in both meta-positions and a hy­droxy group in the para-position. The substituted aryl moiety forms an extensive conjugated π-electron system that can give rise to the emergence of π–π inter­actions in the crystal packing. Indeed, in the structure of (III), we observed the formation of supra­molecular tetra­meric synthons which comprise hydrogen-bonded dimers associated into tetra­mers through π–π inter­actions of overlapping benzene rings.

Computing details

For all compounds, data collection: COLLECT (Bruker, 2004); cell refinement: SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO (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, 2012); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

	Fig. 1. The molecular structure of (I), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. The molecular structure of (II), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 3. The molecular structure of (III), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 4. A fragment of the crystal packing for (I), showing N—H···O hydrogen-bonded chains with the graph-set descriptor C(10).
	Fig. 5. A fragment of the crystal packing for (II), showing the C—H···O hydrogen bonding (dashed lines).
	Fig. 6. A fragment of the crystal packing for (III), showing tetrameric synthon formed by O—H···O hydrogen bonds and π–π interactions.

(I) 5-[4-(Diethylamino)benzyl]-2,2-dimethyl-1,3-dioxane-4,6-dione

Crystal data

C17H23NO4	F(000) = 1312
Mr = 305.36	Dx = 1.224 Mg m^−3
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 41560 reflections
a = 15.0721 (4) Å	θ = 1.0–27.1°
b = 11.3109 (3) Å	µ = 0.09 mm^−1
c = 19.4443 (4) Å	T = 190 K
V = 3314.85 (14) Å^3	Block, colourless
Z = 8	0.42 × 0.25 × 0.18 mm

Data collection

Nonius KappaCCD diffractometer	2532 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.036
Graphite monochromator	θmax = 27.0°, θmin = 2.5°
CCD scans	h = −19→19
6647 measured reflections	k = −14→14
3586 independent reflections	l = −24→24

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.048	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.135	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0749P)^2 + 0.3201P] where P = (Fo^2 + 2Fc^2)/3
3586 reflections	(Δ/σ)max = 0.004
207 parameters	Δρmax = 0.42 e Å^−3
0 restraints	Δρmin = −0.32 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
O19	−0.39182 (8)	0.89445 (11)	0.25622 (6)	0.0368 (3)
O3	−0.22071 (7)	0.89290 (11)	0.10008 (6)	0.0304 (3)
N16	−0.70440 (9)	0.52977 (13)	0.07922 (7)	0.0298 (3)
O1	−0.25444 (7)	0.87494 (11)	0.21756 (5)	0.0326 (3)
O20	−0.32271 (7)	0.93560 (12)	0.02228 (6)	0.0342 (3)
C8	−0.52464 (9)	0.81687 (14)	0.10696 (8)	0.0235 (4)
C10	−0.63975 (10)	0.71860 (15)	0.04146 (8)	0.0283 (4)
H2	−0.6781	0.7176	0.0040	0.034*
C9	−0.58260 (10)	0.81321 (15)	0.05149 (8)	0.0271 (4)
H3	−0.5831	0.8756	0.0203	0.033*
C13	−0.52375 (10)	0.71987 (15)	0.15134 (8)	0.0275 (4)
H4	−0.4839	0.7192	0.1879	0.033*
C6	−0.34447 (11)	0.88844 (14)	0.20485 (8)	0.0265 (4)
C4	−0.30898 (10)	0.90911 (14)	0.08390 (8)	0.0254 (4)
C17	−0.76788 (11)	0.52129 (17)	0.13946 (9)	0.0370 (4)
H7A	−0.8090	0.4569	0.1313	0.044*
H7B	−0.7345	0.5027	0.1807	0.044*
C7	−0.46781 (10)	0.92404 (15)	0.12018 (8)	0.0269 (4)
H8A	−0.4930	0.9673	0.1586	0.032*
H8B	−0.4709	0.9750	0.0801	0.032*
C5	−0.37157 (10)	0.89992 (13)	0.13570 (7)	0.0233 (3)
C12	−0.58020 (10)	0.62493 (15)	0.14266 (8)	0.0285 (4)
H10	−0.5788	0.5614	0.1730	0.034*
C11	−0.63914 (10)	0.62607 (14)	0.08772 (8)	0.0263 (4)
C2	−0.20050 (11)	0.83192 (17)	0.16270 (9)	0.0345 (4)
C15	−0.66273 (13)	0.41035 (17)	0.06799 (11)	0.0439 (5)
H13A	−0.6246	0.3919	0.1068	0.053*
H13B	−0.7091	0.3509	0.0661	0.053*
C18	−0.81919 (13)	0.63211 (19)	0.15121 (10)	0.0455 (5)
H14A	−0.7792	0.6949	0.1631	0.068*
H14B	−0.8607	0.6201	0.1880	0.068*
H14C	−0.8508	0.6527	0.1100	0.068*
C21	−0.21448 (15)	0.70056 (19)	0.15389 (10)	0.0498 (5)
H15A	−0.1985	0.6605	0.1956	0.075*
H15B	−0.1781	0.6723	0.1169	0.075*
H15C	−0.2757	0.6854	0.1436	0.075*
C22	−0.10625 (12)	0.8645 (2)	0.18035 (11)	0.0553 (6)
H16A	−0.1014	0.9488	0.1844	0.083*
H16B	−0.0673	0.8371	0.1447	0.083*
H16C	−0.0900	0.8283	0.2232	0.083*
C14	−0.60972 (16)	0.4049 (2)	0.00370 (14)	0.0656 (7)
H17A	−0.6458	0.4293	−0.0344	0.098*
H17B	−0.5897	0.3253	−0.0036	0.098*
H17C	−0.5594	0.4565	0.0076	0.098*
HN16	−0.7422 (14)	0.548 (2)	0.0384 (10)	0.051 (6)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O19	0.0388 (7)	0.0469 (8)	0.0247 (6)	−0.0034 (6)	0.0066 (5)	−0.0072 (5)
O3	0.0221 (6)	0.0414 (7)	0.0277 (6)	0.0028 (5)	0.0011 (5)	0.0019 (5)
N16	0.0285 (7)	0.0276 (8)	0.0332 (8)	−0.0021 (6)	−0.0092 (6)	0.0010 (6)
O1	0.0293 (6)	0.0439 (8)	0.0248 (6)	0.0008 (5)	−0.0034 (5)	−0.0052 (5)
O20	0.0293 (6)	0.0499 (8)	0.0235 (6)	0.0060 (6)	0.0032 (5)	0.0070 (5)
C8	0.0190 (7)	0.0263 (9)	0.0250 (8)	0.0029 (6)	0.0038 (6)	−0.0016 (6)
C10	0.0272 (8)	0.0332 (10)	0.0244 (8)	0.0030 (7)	−0.0047 (6)	−0.0014 (7)
C9	0.0267 (8)	0.0292 (9)	0.0253 (8)	0.0044 (7)	0.0020 (7)	0.0026 (7)
C13	0.0231 (8)	0.0348 (10)	0.0247 (8)	−0.0015 (7)	−0.0040 (6)	0.0005 (7)
C6	0.0302 (8)	0.0230 (9)	0.0264 (8)	−0.0034 (7)	0.0004 (7)	−0.0044 (7)
C4	0.0226 (8)	0.0256 (9)	0.0280 (8)	0.0011 (7)	0.0009 (6)	−0.0013 (7)
C17	0.0364 (10)	0.0431 (11)	0.0316 (9)	−0.0167 (8)	−0.0078 (8)	0.0109 (8)
C7	0.0250 (8)	0.0266 (9)	0.0292 (8)	0.0017 (7)	0.0043 (7)	−0.0003 (7)
C5	0.0239 (8)	0.0206 (8)	0.0253 (8)	−0.0021 (6)	0.0007 (6)	−0.0016 (6)
C12	0.0270 (8)	0.0299 (9)	0.0288 (8)	−0.0026 (7)	−0.0027 (7)	0.0054 (7)
C11	0.0231 (8)	0.0275 (9)	0.0283 (8)	−0.0014 (7)	−0.0011 (6)	−0.0019 (7)
C2	0.0313 (9)	0.0445 (11)	0.0278 (9)	0.0078 (8)	−0.0018 (7)	−0.0002 (8)
C15	0.0406 (10)	0.0325 (11)	0.0585 (12)	0.0018 (8)	−0.0150 (9)	−0.0060 (9)
C18	0.0428 (11)	0.0549 (13)	0.0389 (10)	−0.0079 (10)	0.0086 (9)	−0.0006 (9)
C21	0.0640 (13)	0.0414 (12)	0.0441 (11)	0.0172 (10)	0.0016 (10)	0.0007 (9)
C22	0.0313 (10)	0.0883 (19)	0.0465 (12)	0.0063 (11)	−0.0073 (9)	0.0032 (11)
C14	0.0586 (13)	0.0534 (15)	0.0848 (17)	0.0049 (11)	0.0067 (13)	−0.0183 (13)

Geometric parameters (Å, º)

O19—C6	1.229 (2)	C17—H7B	0.9700
O3—C4	1.3794 (18)	C7—C5	1.506 (2)
O3—C2	1.432 (2)	C7—H8A	0.9700
N16—C11	1.477 (2)	C7—H8B	0.9700
N16—C15	1.505 (2)	C12—C11	1.389 (2)
N16—C17	1.515 (2)	C12—H10	0.9300
N16—HN16	1.00 (2)	C2—C22	1.507 (3)
O1—C6	1.388 (2)	C2—C21	1.510 (3)
O1—C2	1.427 (2)	C15—C14	1.485 (3)
O20—C4	1.252 (2)	C15—H13A	0.9700
C8—C9	1.388 (2)	C15—H13B	0.9700
C8—C13	1.396 (2)	C18—H14A	0.9600
C8—C7	1.506 (2)	C18—H14B	0.9600
C10—C11	1.380 (2)	C18—H14C	0.9600
C10—C9	1.387 (2)	C21—H15A	0.9600
C10—H2	0.9300	C21—H15B	0.9600
C9—H3	0.9300	C21—H15C	0.9600
C13—C12	1.380 (2)	C22—H16A	0.9600
C13—H4	0.9300	C22—H16B	0.9600
C6—C5	1.411 (2)	C22—H16C	0.9600
C4—C5	1.384 (2)	C14—H17A	0.9600
C17—C18	1.491 (3)	C14—H17B	0.9600
C17—H7A	0.9700	C14—H17C	0.9600
C4—O3—C2	117.59 (12)	C13—C12—H10	120.6
C11—N16—C15	113.58 (13)	C11—C12—H10	120.6
C11—N16—C17	112.37 (13)	C10—C11—C12	120.82 (15)
C15—N16—C17	108.58 (14)	C10—C11—N16	118.81 (14)
C11—N16—HN16	108.2 (13)	C12—C11—N16	120.34 (14)
C15—N16—HN16	108.2 (13)	O1—C2—O3	110.50 (13)
C17—N16—HN16	105.5 (12)	O1—C2—C22	106.47 (15)
C6—O1—C2	117.49 (12)	O3—C2—C22	106.04 (15)
C9—C8—C13	117.57 (15)	O1—C2—C21	109.92 (15)
C9—C8—C7	120.95 (14)	O3—C2—C21	110.34 (14)
C13—C8—C7	121.43 (14)	C22—C2—C21	113.44 (17)
C11—C10—C9	119.29 (14)	C14—C15—N16	112.59 (17)
C11—C10—H2	120.4	C14—C15—H13A	109.1
C9—C10—H2	120.4	N16—C15—H13A	109.1
C10—C9—C8	121.52 (15)	C14—C15—H13B	109.1
C10—C9—H3	119.2	N16—C15—H13B	109.1
C8—C9—H3	119.2	H13A—C15—H13B	107.8
C12—C13—C8	122.00 (14)	C17—C18—H14A	109.5
C12—C13—H4	119.0	C17—C18—H14B	109.5
C8—C13—H4	119.0	H14A—C18—H14B	109.5
O19—C6—O1	115.41 (14)	C17—C18—H14C	109.5
O19—C6—C5	126.94 (15)	H14A—C18—H14C	109.5
O1—C6—C5	117.56 (14)	H14B—C18—H14C	109.5
O20—C4—O3	114.16 (13)	C2—C21—H15A	109.5
O20—C4—C5	127.00 (14)	C2—C21—H15B	109.5
O3—C4—C5	118.78 (14)	H15A—C21—H15B	109.5
C18—C17—N16	113.13 (14)	C2—C21—H15C	109.5
C18—C17—H7A	109.0	H15A—C21—H15C	109.5
N16—C17—H7A	109.0	H15B—C21—H15C	109.5
C18—C17—H7B	109.0	C2—C22—H16A	109.5
N16—C17—H7B	109.0	C2—C22—H16B	109.5
H7A—C17—H7B	107.8	H16A—C22—H16B	109.5
C8—C7—C5	115.84 (13)	C2—C22—H16C	109.5
C8—C7—H8A	108.3	H16A—C22—H16C	109.5
C5—C7—H8A	108.3	H16B—C22—H16C	109.5
C8—C7—H8B	108.3	C15—C14—H17A	109.5
C5—C7—H8B	108.3	C15—C14—H17B	109.5
H8A—C7—H8B	107.4	H17A—C14—H17B	109.5
C4—C5—C6	120.20 (14)	C15—C14—H17C	109.5
C4—C5—C7	119.80 (14)	H17A—C14—H17C	109.5
C6—C5—C7	119.09 (13)	H17B—C14—H17C	109.5
C13—C12—C11	118.75 (15)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C7—H8A···O19	0.97	2.57	2.9019	100
C7—H8B···O20	0.97	2.54	2.9023	102
N16—HN16···O20^i	1.00 (2)	1.70 (2)	2.688 (2)	169 (2)
C10—H2···O3^i	0.93	2.46	3.264 (2)	144
C17—H7B···O1^ii	0.97	2.46	3.253 (2)	139
C17—H7B···O19^ii	0.97	2.57	3.459 (2)	152
C12—H10···O19^ii	0.93	2.38	3.292 (2)	168

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

(II) 2,2-Dimethyl-5-(2,4,6-trimethoxybenzyl)-1,3-dioxane-4,6-dione

Crystal data

C16H20O7	F(000) = 1376
Mr = 324.32	Dx = 1.438 Mg m^−3
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 15283 reflections
a = 9.8128 (2) Å	θ = 1.0–27.5°
b = 10.0235 (2) Å	µ = 0.11 mm^−1
c = 30.4669 (6) Å	T = 190 K
V = 2996.68 (10) Å^3	Plate, colourless
Z = 8	0.26 × 0.24 × 0.10 mm

Data collection

Nonius KappaCCD diffractometer	2421 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.040
Graphite monochromator	θmax = 27.4°, θmin = 2.5°
CCD scans	h = −12→12
6059 measured reflections	k = −12→12
3374 independent reflections	l = −39→39

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.042	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.105	H-atom parameters constrained
S = 1.00	w = 1/[σ^2(Fo^2) + (0.0465P)^2 + 0.7724P] where P = (Fo^2 + 2Fc^2)/3
3374 reflections	(Δ/σ)max = 0.009
213 parameters	Δρmax = 0.27 e Å^−3
0 restraints	Δρmin = −0.24 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
O3	0.70620 (11)	−0.09851 (11)	0.07913 (4)	0.0200 (3)
O1	0.63264 (10)	0.08643 (11)	0.03698 (3)	0.0208 (3)
O15	0.36539 (11)	0.25988 (11)	0.21152 (4)	0.0219 (3)
O20	0.50007 (11)	0.23932 (11)	0.06669 (4)	0.0230 (3)
O21	0.65142 (12)	−0.11714 (12)	0.14892 (4)	0.0264 (3)
O17	−0.03063 (10)	0.01509 (12)	0.16158 (4)	0.0246 (3)
O19	0.40355 (10)	−0.04681 (11)	0.09580 (4)	0.0223 (3)
C5	0.62662 (15)	0.10193 (16)	0.11675 (5)	0.0178 (3)
H1	0.7135	0.1476	0.1219	0.021*
C14	0.28290 (17)	0.34188 (17)	0.23906 (6)	0.0248 (4)
H2A	0.2214	0.3932	0.2213	0.037*
H2B	0.3401	0.4010	0.2556	0.037*
H2C	0.2316	0.2866	0.2588	0.037*
C9	0.32122 (15)	0.01330 (15)	0.12661 (5)	0.0181 (3)
C11	0.10456 (15)	0.05114 (16)	0.16010 (5)	0.0196 (4)
C6	0.57935 (15)	0.14942 (16)	0.07239 (5)	0.0181 (3)
C12	0.16063 (16)	0.14689 (16)	0.18732 (5)	0.0202 (4)
H6	0.1068	0.1932	0.2073	0.024*
C10	0.18333 (15)	−0.01686 (15)	0.12965 (5)	0.0190 (4)
H7	0.1446	−0.0814	0.1116	0.023*
C22	0.87603 (16)	0.05431 (17)	0.04927 (6)	0.0247 (4)
H8A	0.8727	0.1099	0.0749	0.037*
H8B	0.8973	0.1079	0.0241	0.037*
H8C	0.9450	−0.0127	0.0530	0.037*
C4	0.66056 (15)	−0.04586 (16)	0.11732 (5)	0.0187 (3)
C7	0.53346 (15)	0.14686 (17)	0.15413 (5)	0.0207 (4)
H10A	0.5723	0.1135	0.1813	0.025*
H10B	0.5378	0.2434	0.1555	0.025*
C23	0.73435 (18)	−0.09981 (17)	0.00263 (5)	0.0265 (4)
H11A	0.7991	−0.1710	0.0058	0.040*
H11B	0.7566	−0.0479	−0.0229	0.040*
H11C	0.6445	−0.1365	−0.0006	0.040*
C18	0.35868 (17)	−0.16978 (16)	0.07704 (6)	0.0236 (4)
H12A	0.3385	−0.2322	0.1001	0.035*
H12B	0.4292	−0.2054	0.0586	0.035*
H12C	0.2782	−0.1544	0.0599	0.035*
C2	0.73884 (15)	−0.01231 (16)	0.04268 (5)	0.0199 (4)
C8	0.38392 (15)	0.10803 (16)	0.15365 (5)	0.0175 (3)
C16	−0.10763 (16)	0.06787 (18)	0.19715 (6)	0.0267 (4)
H15A	−0.0627	0.0474	0.2243	0.040*
H15B	−0.1970	0.0289	0.1971	0.040*
H15C	−0.1152	0.1629	0.1940	0.040*
C13	0.29995 (15)	0.17235 (15)	0.18408 (5)	0.0184 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O3	0.0245 (6)	0.0159 (6)	0.0196 (6)	0.0020 (5)	0.0024 (5)	0.0005 (5)
O1	0.0229 (6)	0.0206 (6)	0.0189 (6)	0.0049 (4)	−0.0004 (5)	0.0003 (5)
O15	0.0239 (6)	0.0207 (6)	0.0212 (6)	−0.0012 (5)	0.0019 (5)	−0.0073 (5)
O20	0.0212 (6)	0.0181 (6)	0.0298 (7)	0.0038 (5)	−0.0009 (5)	0.0007 (5)
O21	0.0319 (7)	0.0243 (7)	0.0228 (7)	−0.0006 (5)	0.0010 (5)	0.0057 (5)
O17	0.0175 (6)	0.0285 (7)	0.0277 (7)	−0.0019 (5)	0.0049 (5)	−0.0045 (5)
O19	0.0204 (6)	0.0215 (6)	0.0251 (7)	−0.0034 (5)	0.0041 (5)	−0.0102 (5)
C5	0.0152 (7)	0.0184 (8)	0.0199 (8)	−0.0018 (6)	0.0006 (6)	−0.0026 (7)
C14	0.0315 (9)	0.0210 (9)	0.0220 (9)	0.0001 (8)	0.0039 (7)	−0.0059 (7)
C9	0.0210 (8)	0.0161 (8)	0.0173 (9)	0.0015 (6)	0.0025 (6)	0.0003 (7)
C11	0.0171 (8)	0.0186 (8)	0.0231 (9)	−0.0011 (6)	0.0004 (6)	0.0032 (7)
C6	0.0167 (7)	0.0160 (8)	0.0216 (9)	−0.0043 (6)	0.0020 (6)	−0.0012 (7)
C12	0.0221 (8)	0.0183 (8)	0.0202 (9)	0.0016 (7)	0.0051 (7)	−0.0013 (7)
C10	0.0206 (8)	0.0165 (8)	0.0199 (9)	−0.0008 (6)	−0.0010 (6)	−0.0014 (7)
C22	0.0230 (8)	0.0223 (9)	0.0287 (10)	0.0020 (7)	0.0057 (7)	0.0013 (8)
C4	0.0158 (7)	0.0217 (8)	0.0185 (8)	−0.0017 (7)	−0.0015 (6)	0.0000 (7)
C7	0.0190 (8)	0.0221 (9)	0.0210 (9)	−0.0015 (7)	−0.0003 (6)	−0.0048 (7)
C23	0.0346 (9)	0.0222 (9)	0.0226 (9)	0.0047 (7)	0.0014 (7)	−0.0014 (8)
C18	0.0294 (9)	0.0169 (8)	0.0244 (9)	−0.0024 (7)	0.0028 (7)	−0.0045 (7)
C2	0.0224 (8)	0.0167 (8)	0.0206 (9)	0.0044 (6)	0.0037 (7)	0.0034 (7)
C8	0.0190 (8)	0.0164 (8)	0.0171 (8)	−0.0004 (6)	0.0012 (6)	0.0010 (7)
C16	0.0207 (8)	0.0340 (10)	0.0256 (10)	−0.0002 (7)	0.0057 (7)	−0.0006 (8)
C13	0.0231 (8)	0.0140 (8)	0.0180 (8)	0.0001 (6)	−0.0020 (6)	−0.0005 (7)

Geometric parameters (Å, º)

O3—C4	1.3539 (19)	C11—C10	1.386 (2)
O3—C2	1.4430 (18)	C12—C13	1.394 (2)
O1—C6	1.3551 (18)	C12—H6	0.9300
O1—C2	1.4477 (18)	C10—H7	0.9300
O15—C13	1.3714 (18)	C22—C2	1.516 (2)
O15—C14	1.4265 (18)	C22—H8A	0.9600
O20—C6	1.2032 (18)	C22—H8B	0.9600
O21—C4	1.2022 (18)	C22—H8C	0.9600
O17—C11	1.3757 (19)	C7—C8	1.518 (2)
O17—C16	1.4231 (19)	C7—H10A	0.9700
O19—C9	1.3773 (18)	C7—H10B	0.9700
O19—C18	1.4282 (18)	C23—C2	1.503 (2)
C5—C6	1.506 (2)	C23—H11A	0.9600
C5—C4	1.518 (2)	C23—H11B	0.9600
C5—C7	1.528 (2)	C23—H11C	0.9600
C5—H1	0.9800	C18—H12A	0.9600
C14—H2A	0.9600	C18—H12B	0.9600
C14—H2B	0.9600	C18—H12C	0.9600
C14—H2C	0.9600	C8—C13	1.398 (2)
C9—C10	1.390 (2)	C16—H15A	0.9600
C9—C8	1.400 (2)	C16—H15B	0.9600
C11—C12	1.383 (2)	C16—H15C	0.9600
C4—O3—C2	120.09 (12)	O21—C4—C5	124.94 (15)
C6—O1—C2	120.05 (12)	O3—C4—C5	116.29 (13)
C13—O15—C14	117.48 (12)	C8—C7—C5	119.70 (13)
C11—O17—C16	116.07 (12)	C8—C7—H10A	107.4
C9—O19—C18	118.00 (12)	C5—C7—H10A	107.4
C6—C5—C4	112.72 (13)	C8—C7—H10B	107.4
C6—C5—C7	113.04 (13)	C5—C7—H10B	107.4
C4—C5—C7	114.21 (13)	H10A—C7—H10B	106.9
C6—C5—H1	105.3	C2—C23—H11A	109.5
C4—C5—H1	105.3	C2—C23—H11B	109.5
C7—C5—H1	105.3	H11A—C23—H11B	109.5
O15—C14—H2A	109.5	C2—C23—H11C	109.5
O15—C14—H2B	109.5	H11A—C23—H11C	109.5
H2A—C14—H2B	109.5	H11B—C23—H11C	109.5
O15—C14—H2C	109.5	O19—C18—H12A	109.5
H2A—C14—H2C	109.5	O19—C18—H12B	109.5
H2B—C14—H2C	109.5	H12A—C18—H12B	109.5
O19—C9—C10	121.43 (14)	O19—C18—H12C	109.5
O19—C9—C8	116.11 (13)	H12A—C18—H12C	109.5
C10—C9—C8	122.43 (14)	H12B—C18—H12C	109.5
O17—C11—C12	123.12 (14)	O3—C2—O1	110.00 (11)
O17—C11—C10	115.50 (14)	O3—C2—C23	105.59 (13)
C12—C11—C10	121.38 (14)	O1—C2—C23	106.28 (12)
O20—C6—O1	118.91 (14)	O3—C2—C22	111.04 (13)
O20—C6—C5	124.44 (14)	O1—C2—C22	110.73 (13)
O1—C6—C5	116.64 (13)	C23—C2—C22	112.98 (13)
C11—C12—C13	118.34 (15)	C13—C8—C9	116.37 (14)
C11—C12—H6	120.8	C13—C8—C7	116.43 (14)
C13—C12—H6	120.8	C9—C8—C7	127.18 (14)
C11—C10—C9	118.72 (15)	O17—C16—H15A	109.5
C11—C10—H7	120.6	O17—C16—H15B	109.5
C9—C10—H7	120.6	H15A—C16—H15B	109.5
C2—C22—H8A	109.5	O17—C16—H15C	109.5
C2—C22—H8B	109.5	H15A—C16—H15C	109.5
H8A—C22—H8B	109.5	H15B—C16—H15C	109.5
C2—C22—H8C	109.5	O15—C13—C12	122.21 (14)
H8A—C22—H8C	109.5	O15—C13—C8	115.04 (13)
H8B—C22—H8C	109.5	C12—C13—C8	122.72 (15)
O21—C4—O3	118.76 (14)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C22—H8C···O20^i	0.96	2.58	3.425 (2)	147
C16—H15B···O21^ii	0.96	2.55	3.345 (2)	140

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

(III) 5-(4-Hydroxy-3,5-dimethoxybenzyl)-2,2-dimethyl-1,3-dioxane-4,6-dione

Crystal data

C15H18O7	F(000) = 2624
Mr = 310.29	Dx = 1.408 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 22.9942 (5) Å	Cell parameters from 14754 reflections
b = 10.1840 (2) Å	θ = 1.0–27.5°
c = 26.9904 (7) Å	µ = 0.11 mm^−1
β = 112.125 (1)°	T = 190 K
V = 5855.0 (2) Å^3	Block, colourless
Z = 16	0.32 × 0.14 × 0.10 mm

Data collection

Nonius KappaCCD diffractometer	3333 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.071
Graphite monochromator	θmax = 27.5°, θmin = 4.1°
CCD scans	h = −29→29
11293 measured reflections	k = −13→12
6610 independent reflections	l = −35→34

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.056	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.128	H-atom parameters constrained
S = 0.96	w = 1/[σ^2(Fo^2) + (0.0491P)^2] where P = (Fo^2 + 2Fc^2)/3
6610 reflections	(Δ/σ)max < 0.001
407 parameters	Δρmax = 0.26 e Å^−3
1 restraint	Δρmin = −0.28 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
O19A	0.68746 (7)	0.22214 (15)	0.00532 (6)	0.0288 (4)
O3A	0.75965 (7)	0.57215 (14)	0.01900 (6)	0.0285 (4)
O16A	0.64076 (8)	0.02557 (15)	0.22066 (7)	0.0310 (4)
H16A	0.6485	0.0576	0.2503	0.046*
O1B	0.44928 (7)	−0.16261 (16)	0.18401 (7)	0.0315 (4)
O16B	0.65988 (7)	0.51559 (16)	0.13938 (7)	0.0313 (4)
H16B	0.6829	0.5362	0.1698	0.047*
O17A	0.73529 (7)	0.18461 (15)	0.27644 (7)	0.0335 (4)
O15B	0.58398 (7)	0.40497 (15)	0.04951 (6)	0.0313 (4)
O3B	0.47010 (7)	−0.16576 (16)	0.10492 (6)	0.0323 (4)
O15A	0.61118 (7)	−0.02194 (15)	0.11918 (6)	0.0302 (4)
O17B	0.64798 (8)	0.47330 (16)	0.23247 (7)	0.0347 (4)
O1A	0.67768 (7)	0.42422 (15)	−0.02468 (6)	0.0284 (4)
O20B	0.45815 (8)	0.01801 (16)	0.05925 (7)	0.0372 (5)
C11A	0.67329 (10)	0.0924 (2)	0.19515 (10)	0.0231 (6)
O19B	0.42579 (8)	0.02352 (18)	0.21338 (7)	0.0398 (5)
C9A	0.75431 (10)	0.2423 (2)	0.19489 (10)	0.0247 (6)
H2	0.7864	0.3007	0.2130	0.030*
O20A	0.83454 (8)	0.51768 (17)	0.09498 (7)	0.0448 (5)
C8A	0.73847 (10)	0.2205 (2)	0.14057 (10)	0.0229 (6)
C10B	0.60468 (10)	0.4106 (2)	0.18890 (10)	0.0246 (6)
C12A	0.65821 (10)	0.0684 (2)	0.14124 (10)	0.0222 (6)
C6B	0.44930 (11)	−0.0293 (3)	0.18611 (10)	0.0284 (6)
C7B	0.46316 (10)	0.1855 (2)	0.14484 (10)	0.0304 (6)
H7A	0.4273	0.1955	0.1115	0.037*
H7B	0.4506	0.2148	0.1735	0.037*
C4B	0.46868 (10)	−0.0324 (2)	0.10159 (10)	0.0271 (6)
C7A	0.77508 (10)	0.2871 (2)	0.11156 (10)	0.0279 (6)
H9A	0.7902	0.2201	0.0938	0.033*
H9B	0.8116	0.3287	0.1380	0.033*
C18A	0.77638 (11)	0.2876 (2)	0.30543 (10)	0.0355 (7)
H10A	0.8174	0.2737	0.3048	0.053*
H10B	0.7790	0.2875	0.3418	0.053*
H10C	0.7603	0.3705	0.2892	0.053*
C11B	0.61265 (10)	0.4346 (2)	0.14147 (10)	0.0250 (6)
C13B	0.52368 (10)	0.2968 (2)	0.09572 (10)	0.0268 (6)
H12	0.4964	0.2583	0.0643	0.032*
C13A	0.69063 (10)	0.1314 (2)	0.11425 (10)	0.0233 (6)
H13	0.6805	0.1144	0.0781	0.028*
C6A	0.70026 (10)	0.3358 (2)	0.01592 (10)	0.0236 (6)
C10A	0.72232 (10)	0.1770 (2)	0.22221 (9)	0.0237 (6)
C12B	0.57198 (10)	0.3768 (2)	0.09423 (10)	0.0245 (6)
C5A	0.73943 (10)	0.3910 (2)	0.06974 (9)	0.0223 (6)
H17	0.7104	0.4346	0.0833	0.027*
C9B	0.55630 (10)	0.3305 (2)	0.19025 (10)	0.0291 (6)
H18	0.5513	0.3152	0.2224	0.035*
C22A	0.69361 (12)	0.6065 (2)	−0.07065 (10)	0.0370 (7)
H19A	0.7044	0.6979	−0.0686	0.055*
H19B	0.6521	0.5941	−0.0970	0.055*
H19C	0.7231	0.5567	−0.0805	0.055*
C2B	0.48196 (11)	−0.2303 (2)	0.15522 (10)	0.0288 (6)
C14B	0.54495 (11)	0.3423 (3)	0.00071 (10)	0.0386 (7)
H21A	0.5481	0.2487	0.0053	0.058*
H21B	0.5585	0.3672	−0.0275	0.058*
H21C	0.5021	0.3690	−0.0083	0.058*
C8B	0.51559 (10)	0.2736 (2)	0.14324 (10)	0.0255 (6)
C22B	0.45127 (12)	−0.3631 (2)	0.14144 (11)	0.0409 (7)
H23A	0.4076	−0.3524	0.1198	0.061*
H23B	0.4555	−0.4088	0.1737	0.061*
H23C	0.4712	−0.4129	0.1220	0.061*
C21B	0.55136 (10)	−0.2401 (2)	0.18788 (11)	0.0357 (7)
H24A	0.5712	−0.2906	0.1686	0.054*
H24B	0.5578	−0.2823	0.2213	0.054*
H24C	0.5693	−0.1537	0.1945	0.054*
C2A	0.69550 (10)	0.5607 (2)	−0.01715 (10)	0.0259 (6)
C5B	0.48038 (10)	0.0394 (2)	0.15315 (9)	0.0230 (6)
H26	0.5257	0.0353	0.1737	0.028*
C4A	0.78254 (11)	0.4965 (2)	0.06355 (10)	0.0276 (6)
C21A	0.65274 (11)	0.6377 (2)	0.00289 (11)	0.0376 (7)
H28A	0.6565	0.6049	0.0373	0.056*
H28B	0.6101	0.6285	−0.0218	0.056*
H28C	0.6644	0.7287	0.0059	0.056*
C14A	0.59698 (12)	−0.0571 (3)	0.06491 (11)	0.0434 (7)
H29A	0.5824	0.0189	0.0426	0.065*
H29B	0.5649	−0.1233	0.0544	0.065*
H29C	0.6340	−0.0908	0.0610	0.065*
C18B	0.64126 (13)	0.4580 (3)	0.28239 (11)	0.0458 (8)
H30A	0.6010	0.4906	0.2796	0.069*
H30B	0.6737	0.5063	0.3094	0.069*
H30C	0.6446	0.3667	0.2919	0.069*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O19A	0.0338 (10)	0.0249 (10)	0.0303 (11)	−0.0059 (8)	0.0152 (8)	−0.0009 (8)
O3A	0.0253 (9)	0.0283 (9)	0.0279 (10)	−0.0059 (7)	0.0055 (8)	0.0058 (8)
O16A	0.0363 (10)	0.0367 (10)	0.0249 (10)	−0.0101 (8)	0.0172 (9)	−0.0030 (8)
O1B	0.0302 (9)	0.0383 (11)	0.0291 (11)	−0.0053 (8)	0.0149 (8)	0.0068 (8)
O16B	0.0340 (10)	0.0326 (10)	0.0283 (10)	−0.0091 (8)	0.0127 (8)	−0.0054 (9)
O17A	0.0412 (10)	0.0353 (10)	0.0233 (10)	−0.0132 (8)	0.0115 (8)	−0.0067 (8)
O15B	0.0323 (9)	0.0390 (10)	0.0229 (10)	−0.0101 (8)	0.0109 (8)	−0.0028 (8)
O3B	0.0408 (10)	0.0340 (11)	0.0218 (10)	−0.0076 (8)	0.0113 (8)	−0.0026 (8)
O15A	0.0330 (9)	0.0346 (10)	0.0226 (10)	−0.0142 (8)	0.0101 (8)	−0.0043 (8)
O17B	0.0403 (10)	0.0402 (10)	0.0245 (11)	−0.0089 (8)	0.0133 (9)	−0.0066 (8)
O1A	0.0295 (9)	0.0235 (9)	0.0277 (10)	−0.0032 (7)	0.0056 (8)	0.0019 (8)
O20B	0.0458 (11)	0.0442 (11)	0.0221 (11)	−0.0051 (9)	0.0134 (9)	0.0038 (9)
C11A	0.0231 (13)	0.0219 (13)	0.0279 (15)	−0.0012 (10)	0.0138 (11)	0.0044 (11)
O19B	0.0414 (11)	0.0568 (12)	0.0301 (11)	0.0046 (9)	0.0234 (9)	0.0034 (9)
C9A	0.0221 (12)	0.0220 (14)	0.0279 (16)	−0.0034 (10)	0.0069 (12)	−0.0010 (11)
O20A	0.0315 (10)	0.0488 (12)	0.0400 (12)	−0.0185 (9)	−0.0029 (9)	0.0093 (9)
C8A	0.0183 (12)	0.0232 (13)	0.0252 (15)	0.0019 (10)	0.0060 (11)	0.0065 (11)
C10B	0.0261 (13)	0.0238 (14)	0.0232 (15)	0.0018 (11)	0.0084 (11)	−0.0057 (12)
C12A	0.0218 (12)	0.0226 (13)	0.0213 (14)	0.0016 (10)	0.0071 (11)	0.0022 (11)
C6B	0.0214 (13)	0.0446 (18)	0.0181 (15)	−0.0027 (12)	0.0062 (11)	0.0035 (13)
C7B	0.0258 (13)	0.0386 (16)	0.0304 (16)	0.0003 (12)	0.0147 (12)	−0.0010 (13)
C4B	0.0241 (13)	0.0328 (16)	0.0253 (16)	−0.0036 (11)	0.0104 (12)	0.0005 (12)
C7A	0.0203 (12)	0.0324 (14)	0.0297 (15)	0.0004 (11)	0.0080 (11)	0.0060 (12)
C18A	0.0402 (15)	0.0340 (15)	0.0276 (16)	−0.0069 (12)	0.0073 (13)	−0.0088 (12)
C11B	0.0229 (13)	0.0230 (13)	0.0307 (16)	−0.0006 (11)	0.0118 (12)	−0.0013 (12)
C13B	0.0252 (13)	0.0271 (14)	0.0262 (15)	−0.0014 (11)	0.0077 (11)	−0.0037 (11)
C13A	0.0266 (13)	0.0265 (13)	0.0192 (14)	0.0033 (11)	0.0113 (11)	0.0028 (11)
C6A	0.0193 (12)	0.0285 (15)	0.0269 (15)	−0.0009 (11)	0.0132 (11)	0.0016 (12)
C10A	0.0257 (13)	0.0254 (14)	0.0192 (14)	0.0020 (11)	0.0075 (11)	0.0011 (11)
C12B	0.0285 (13)	0.0242 (13)	0.0215 (14)	0.0016 (11)	0.0102 (12)	0.0011 (11)
C5A	0.0224 (12)	0.0231 (13)	0.0228 (14)	−0.0020 (10)	0.0100 (11)	−0.0010 (11)
C9B	0.0312 (14)	0.0315 (15)	0.0269 (16)	0.0014 (12)	0.0134 (12)	0.0007 (12)
C22A	0.0450 (16)	0.0326 (15)	0.0311 (17)	−0.0031 (12)	0.0119 (13)	0.0061 (13)
C2B	0.0289 (13)	0.0363 (15)	0.0219 (15)	−0.0051 (12)	0.0105 (12)	0.0011 (12)
C14B	0.0383 (15)	0.0497 (18)	0.0258 (16)	−0.0107 (13)	0.0097 (13)	−0.0068 (13)
C8B	0.0243 (13)	0.0228 (13)	0.0307 (16)	0.0023 (11)	0.0119 (12)	0.0008 (11)
C22B	0.0399 (16)	0.0406 (16)	0.0386 (18)	−0.0147 (13)	0.0107 (13)	0.0014 (14)
C21B	0.0270 (14)	0.0346 (15)	0.0424 (18)	−0.0033 (11)	0.0096 (13)	−0.0022 (13)
C2A	0.0228 (13)	0.0233 (14)	0.0290 (15)	−0.0028 (10)	0.0067 (11)	0.0029 (11)
C5B	0.0174 (12)	0.0307 (14)	0.0200 (14)	−0.0026 (10)	0.0061 (10)	−0.0025 (11)
C4A	0.0253 (13)	0.0299 (15)	0.0266 (15)	−0.0017 (11)	0.0087 (12)	0.0000 (12)
C21A	0.0360 (15)	0.0322 (15)	0.0452 (19)	0.0025 (12)	0.0159 (14)	0.0006 (13)
C14A	0.0422 (16)	0.0555 (18)	0.0331 (17)	−0.0186 (14)	0.0147 (14)	−0.0190 (14)
C18B	0.0538 (18)	0.0559 (19)	0.0313 (18)	−0.0101 (15)	0.0202 (15)	−0.0117 (14)

Geometric parameters (Å, º)

O19A—C6A	1.202 (3)	C7A—H9A	0.9700
O3A—C4A	1.357 (3)	C7A—H9B	0.9700
O3A—C2A	1.434 (3)	C18A—H10A	0.9600
O16A—C11A	1.373 (3)	C18A—H10B	0.9600
O16A—H16A	0.8200	C18A—H10C	0.9600
O1B—C6B	1.358 (3)	C11B—C12B	1.396 (3)
O1B—C2B	1.444 (3)	C13B—C8B	1.384 (3)
O16B—C11B	1.382 (3)	C13B—C12B	1.391 (3)
O16B—H16B	0.8200	C13B—H12	0.9300
O17A—C10A	1.382 (3)	C13A—H13	0.9300
O17A—C18A	1.431 (3)	C6A—C5A	1.500 (3)
O15B—C12B	1.366 (3)	C5A—C4A	1.513 (3)
O15B—C14B	1.434 (3)	C5A—H17	0.9800
O3B—C4B	1.360 (3)	C9B—C8B	1.388 (3)
O3B—C2B	1.439 (3)	C9B—H18	0.9300
O15A—C12A	1.373 (3)	C22A—C2A	1.503 (3)
O15A—C14A	1.421 (3)	C22A—H19A	0.9600
O17B—C10B	1.379 (3)	C22A—H19B	0.9600
O17B—C18B	1.421 (3)	C22A—H19C	0.9600
O1A—C6A	1.361 (3)	C2B—C22B	1.506 (3)
O1A—C2A	1.441 (3)	C2B—C21B	1.508 (3)
O20B—C4B	1.192 (3)	C14B—H21A	0.9600
C11A—C12A	1.385 (3)	C14B—H21B	0.9600
C11A—C10A	1.388 (3)	C14B—H21C	0.9600
O19B—C6B	1.193 (3)	C22B—H23A	0.9600
C9A—C8A	1.389 (3)	C22B—H23B	0.9600
C9A—C10A	1.391 (3)	C22B—H23C	0.9600
C9A—H2	0.9300	C21B—H24A	0.9600
O20A—C4A	1.197 (3)	C21B—H24B	0.9600
C8A—C13A	1.396 (3)	C21B—H24C	0.9600
C8A—C7A	1.509 (3)	C2A—C21A	1.508 (3)
C10B—C11B	1.382 (3)	C5B—H26	0.9800
C10B—C9B	1.391 (3)	C21A—H28A	0.9600
C12A—C13A	1.381 (3)	C21A—H28B	0.9600
C6B—C5B	1.507 (3)	C21A—H28C	0.9600
C7B—C8B	1.516 (3)	C14A—H29A	0.9600
C7B—C5B	1.534 (3)	C14A—H29B	0.9600
C7B—H7A	0.9700	C14A—H29C	0.9600
C7B—H7B	0.9700	C18B—H30A	0.9600
C4B—C5B	1.504 (3)	C18B—H30B	0.9600
C7A—C5A	1.539 (3)	C18B—H30C	0.9600
C4A—O3A—C2A	120.85 (17)	C4A—C5A—H17	106.7
C11A—O16A—H16A	109.5	C7A—C5A—H17	106.7
C6B—O1B—C2B	120.49 (19)	C8B—C9B—C10B	119.4 (2)
C11B—O16B—H16B	109.5	C8B—C9B—H18	120.3
C10A—O17A—C18A	117.06 (19)	C10B—C9B—H18	120.3
C12B—O15B—C14B	116.95 (18)	C2A—C22A—H19A	109.5
C4B—O3B—C2B	120.63 (19)	C2A—C22A—H19B	109.5
C12A—O15A—C14A	116.99 (19)	H19A—C22A—H19B	109.5
C10B—O17B—C18B	117.16 (19)	C2A—C22A—H19C	109.5
C6A—O1A—C2A	121.48 (18)	H19A—C22A—H19C	109.5
O16A—C11A—C12A	118.1 (2)	H19B—C22A—H19C	109.5
O16A—C11A—C10A	122.1 (2)	O3B—C2B—O1B	109.75 (18)
C12A—C11A—C10A	119.6 (2)	O3B—C2B—C22B	105.82 (19)
C8A—C9A—C10A	120.1 (2)	O1B—C2B—C22B	105.7 (2)
C8A—C9A—H2	119.9	O3B—C2B—C21B	111.4 (2)
C10A—C9A—H2	119.9	O1B—C2B—C21B	111.6 (2)
C9A—C8A—C13A	119.0 (2)	C22B—C2B—C21B	112.3 (2)
C9A—C8A—C7A	120.0 (2)	O15B—C14B—H21A	109.5
C13A—C8A—C7A	121.0 (2)	O15B—C14B—H21B	109.5
O17B—C10B—C11B	113.8 (2)	H21A—C14B—H21B	109.5
O17B—C10B—C9B	125.2 (2)	O15B—C14B—H21C	109.5
C11B—C10B—C9B	121.0 (2)	H21A—C14B—H21C	109.5
O15A—C12A—C13A	125.2 (2)	H21B—C14B—H21C	109.5
O15A—C12A—C11A	114.8 (2)	C13B—C8B—C9B	119.7 (2)
C13A—C12A—C11A	120.1 (2)	C13B—C8B—C7B	120.9 (2)
O19B—C6B—O1B	118.9 (2)	C9B—C8B—C7B	119.4 (2)
O19B—C6B—C5B	125.5 (2)	C2B—C22B—H23A	109.5
O1B—C6B—C5B	115.6 (2)	C2B—C22B—H23B	109.5
C8B—C7B—C5B	114.44 (19)	H23A—C22B—H23B	109.5
C8B—C7B—H7A	108.7	C2B—C22B—H23C	109.5
C5B—C7B—H7A	108.7	H23A—C22B—H23C	109.5
C8B—C7B—H7B	108.7	H23B—C22B—H23C	109.5
C5B—C7B—H7B	108.7	C2B—C21B—H24A	109.5
H7A—C7B—H7B	107.6	C2B—C21B—H24B	109.5
O20B—C4B—O3B	119.0 (2)	H24A—C21B—H24B	109.5
O20B—C4B—C5B	125.3 (2)	C2B—C21B—H24C	109.5
O3B—C4B—C5B	115.6 (2)	H24A—C21B—H24C	109.5
C8A—C7A—C5A	116.26 (19)	H24B—C21B—H24C	109.5
C8A—C7A—H9A	108.2	O3A—C2A—O1A	109.85 (16)
C5A—C7A—H9A	108.2	O3A—C2A—C22A	106.17 (19)
C8A—C7A—H9B	108.2	O1A—C2A—C22A	105.08 (19)
C5A—C7A—H9B	108.2	O3A—C2A—C21A	110.85 (19)
H9A—C7A—H9B	107.4	O1A—C2A—C21A	111.27 (19)
O17A—C18A—H10A	109.5	C22A—C2A—C21A	113.3 (2)
O17A—C18A—H10B	109.5	C4B—C5B—C6B	111.15 (19)
H10A—C18A—H10B	109.5	C4B—C5B—C7B	112.9 (2)
O17A—C18A—H10C	109.5	C6B—C5B—C7B	112.5 (2)
H10A—C18A—H10C	109.5	C4B—C5B—H26	106.6
H10B—C18A—H10C	109.5	C6B—C5B—H26	106.6
C10B—C11B—O16B	121.6 (2)	C7B—C5B—H26	106.6
C10B—C11B—C12B	119.7 (2)	O20A—C4A—O3A	118.4 (2)
O16B—C11B—C12B	118.7 (2)	O20A—C4A—C5A	124.8 (2)
C8B—C13B—C12B	121.0 (2)	O3A—C4A—C5A	116.72 (19)
C8B—C13B—H12	119.5	C2A—C21A—H28A	109.5
C12B—C13B—H12	119.5	C2A—C21A—H28B	109.5
C12A—C13A—C8A	120.8 (2)	H28A—C21A—H28B	109.5
C12A—C13A—H13	119.6	C2A—C21A—H28C	109.5
C8A—C13A—H13	119.6	H28A—C21A—H28C	109.5
O19A—C6A—O1A	117.4 (2)	H28B—C21A—H28C	109.5
O19A—C6A—C5A	126.5 (2)	O15A—C14A—H29A	109.5
O1A—C6A—C5A	116.1 (2)	O15A—C14A—H29B	109.5
O17A—C10A—C11A	113.6 (2)	H29A—C14A—H29B	109.5
O17A—C10A—C9A	126.1 (2)	O15A—C14A—H29C	109.5
C11A—C10A—C9A	120.3 (2)	H29A—C14A—H29C	109.5
O15B—C12B—C13B	125.3 (2)	H29B—C14A—H29C	109.5
O15B—C12B—C11B	115.5 (2)	O17B—C18B—H30A	109.5
C13B—C12B—C11B	119.2 (2)	O17B—C18B—H30B	109.5
C6A—C5A—C4A	109.77 (19)	H30A—C18B—H30B	109.5
C6A—C5A—C7A	114.36 (19)	O17B—C18B—H30C	109.5
C4A—C5A—C7A	112.26 (18)	H30A—C18B—H30C	109.5
C6A—C5A—H17	106.7	H30B—C18B—H30C	109.5

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O16A—H16A···O17A	0.82	2.26	2.674 (2)	112
O16B—H16B···O17B	0.82	2.22	2.663 (3)	114
C13B—H12···O20B	0.93	2.59	3.191 (3)	123
C13A—H13···O19A	0.93	2.31	3.056 (3)	137
O16A—H16A···O19B^i	0.82	2.29	2.750 (3)	116
O16B—H16B···O17A^ii	0.82	2.42	3.132 (2)	145
C5A—H17···O16B	0.98	2.38	3.329 (3)	164
C21B—H24C···O16A	0.96	2.38	3.310 (3)	164
C5B—H26···O16A	0.98	2.47	3.447 (3)	177

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