Crystal structure of 3,6-dihy-droxy-4,5-di-methyl-benzene-1,2-dicarbaldehyde.

The title compound, C10H10O4, was synthesized from tetra-methyl-1,4-benzo-quinone. In the crystal, the almost planar mol-ecule (r.m.s. deviation = 0.024 Å) forms intra-molecular hydrogen bonds between the aldehyde and hy-droxy groups and exhibits C 2v symmetry. This achiral mol-ecule crystallizes in the chiral space group P21 with inter-molecular O-H⋯O and C-H⋯O hydrogen bonding and C-H⋯π and C=O⋯π inter-actions stabilizing the crystal packing.

Chemical context

A number of benzo- and naphtho­quinone derivatives with one or two side chains being capable of alkyl­ation after reduction were found to exhibit inhibitory activity against the growth of transplantable tumours in mice. Furthermore, inhibition of nucleic acid biosynthesis and of the activities of coenzyme Q mediated enzyme systems are also known for related compounds composed of 3,6-dihy­droxy-4,5-di­methyl­benzene-1,2-dicarbaldehyde (Lin & Loo, 1977 ▸; Lin et al., 1978 ▸). According to the literature, these compounds are synthesized from tetra­methyl-1,4-benzo­quinone (Lin & Loo, 1977 ▸; Lin et al., 1978 ▸). Here we report the mol­ecular and crystal structure of an achiral derviative crystallizing in a chiral space group.

Structural commentary

The mol­ecular structure of the title compound consists of a benzene ring substituted by two methyl groups, two hy­droxy groups and two aldehyde groups (Fig. 1 ▸). The mol­ecular point group symmetry is C 2v (H atoms excluded). The C—C bond lengths of the methyl substituents are 1.511 (2) and 1.508 (2) Å, the C—O bond lengths of the hy­droxy substituents are 1.354 (2) and 1.350 (2) Å, and the C—C bond lengths of the aldehyde substituents are 1.464 (2) and 1.462 (2) Å. Two intra­molecular O—H⋯H hydrogen bonds between the hy­droxy and aldehyde functions are observed (Table 1 ▸ and Fig. 1 ▸). The mol­ecule is essentially planar (r.m.s. deviation = 0.024 Å), with the largest deviation found for atom O2 [0.047 (1) Å].

Figure 1

The mol­ecular structure of the title compound, showing the atom-numbering scheme and displacement ellipsoids drawn at the 50% probability level.

Table 1

Hydrogen-bond geometry (Å, °)

Cg1 is the centroid of ring C1–C6.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3⋯O2	0.84	1.87	2.6079 (19)	146
O4—H4⋯O1	0.84	1.82	2.5592 (19)	146
O3—H3⋯O4i	0.84	2.40	3.036 (2)	133
O4—H4⋯O2ii	0.84	2.34	2.809 (2)	116
C7—H7⋯O2iii	0.95	2.51	3.427 (2)	162
C10—H10B⋯Cg1iv	0.98	3.13	3.645	114

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) .

Supra­molecular features

In the crystal, mol­ecules are connected along the b axis by O—H⋯O hydrogen bonds and along the c axis by C—H⋯O hydrogen bonds (Table 1 ▸ and Fig. 2 ▸). As a result, chiral crystals composed of achiral mol­ecules are formed. Many examples of such chiral crystals forming from achiral mol­ecules have been reported for decades, but the prediction of chiral crystallization is still impossible (Koshima & Matsuura, 1998 ▸; Matsuura & Koshima, 2005 ▸).

Figure 2

A view of the O—H⋯O hydrogen bonds (dashed lines) present in the crystal lattice of the title compound.

The C8=O2 carbonyl group is stacked on top of the aromatic ring, with the O2⋯Cg1 distance being 3.4846 (19) Å (Cg1 is the centroid of ring C1–C6).

In addition, a weak C—H⋯π inter­action C10—H10B⋯Cg1 (3.131 Å) is also found (Table 1 ▸ and Fig. 3 ▸).

Figure 3

Part of the crystal packing showing the C—H⋯π stacking inter­actions.

Database survey

A search in the Cambridge Structural Database (CSD, Version 5.39, update May 2018; Groom et al., 2016 ▸) for similar 1,2-dicarbaldehyde structures returned five relevant entries: benzene-1,2-dicarbaldehyde [IHEMAJ (Britton, 2002 ▸) and IHEMAJ01 (Mendenhall et al., 2003 ▸)], naphthalene-1,2-dicarbaldehyde (FIYQOT; Britton, 1999 ▸), a chromene-5,6-dicarbaldehyde derivative (IDUCUH; am Ende et al., 2013 ▸) and a cobalt benzene-1,2-dicarbaldehyde complex (JUKZAQ; Lenges et al., 1999 ▸). In the first four structures, the aldehyde functions show C—H⋯O inter­actions (H⋯O distances from 2.226 to 2.360 Å). This is not the case for the cobalt complex JUKZAQ, where the two aldehyde O atoms are facing each other and complexed with cobalt, nor with the title compound where the two aldehyde O atoms are involved in intra­molecular hydrogen bonds and the two aldehyde H atoms are facing each other.

The intra­molecular O—H⋯O inter­action between the 1-carbaldehyde and 2-hy­droxy groups is also observed in compounds such as 1,8-dihy­droxy-2-naphthaldehyde (BABXUA; Peng et al., 2015 ▸) and 2,4,6-tri­hydroxy­benzene-1,3,5-tricarbaldehyde (WEPPUE; von Richthofen et al., 2013 ▸).

Synthesis and crystallization

A mixture of tetra­methyl-1,4-benzo­quinone (2.0406 g, 12.4 mmol) and concentrated piperidine (98.0%, 35 ml) was stirred at room temperature for 35 h. The mixture was evaporated and a white inter­mediate product was obtained. To a solution of the obtained inter­mediate product dissolved in acetic acid (18 ml), a mixture of CrO3 (1.77 g) and 50% acetic acid (35 ml) was added dropwise at 353 K. After 10 min, the reaction mixture was poured onto crushed ice (100 g). The solution was filtered by vacuum filtration and a crude compound was obtained. The crude compound was dissolved in toluene and purified by silica column chromatography to afford 0.567 g (yield 23.5%) of the title compound as a yellow solid (single crystals served for X-ray analysis). IR (KBr, cm−1): 1633 (s), 3436 (m).

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2 ▸. All H atoms were located in difference Fourier maps. C-bound H atoms were constrained using a riding model [C—H = 0.98 Å and U iso(H) = 1.5U eq(C) for methyl H atoms, and C—H = 0.95 Å and U iso(H) = 1.2U eq(C) for the aldehyde H atoms]. O-bound H atoms were constrained using a riding model [O—H = 0.84 Å and U iso(H) = 1.5U eq(O) for hy­droxy H atoms].

Table 2

Experimental details

Crystal data
Chemical formula	C10H10O4
M r	194.18
Crystal system, space group	Monoclinic, P21
Temperature (K)	100
a, b, c (Å)	5.251 (2), 6.317 (2), 12.999 (5)
β (°)	91.643 (4)
V (Å3)	431.0 (3)
Z	2
Radiation type	Mo Kα
μ (mm−1)	0.12
Crystal size (mm)	0.38 × 0.30 × 0.13
Data collection
Diffractometer	Bruker APEXII CCD
Absorption correction	Multi-scan (SADABS; Bruker, 2001 ▸)
T min, T max	0.785, 0.785
No. of measured, independent and observed [I > 2σ(I)] reflections	2328, 1228, 1207
R int	0.014
(sin θ/λ)max (Å−1)	0.650
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.029, 0.082, 1.06
No. of reflections	1228
No. of parameters	131
No. of restraints	1
H-atom treatment	H-atom parameters constrained
Δρmax, Δρmin (e Å−3)	0.25, −0.22
Absolute structure	Flack x determined using 179 quotients [(I +)−(I −)]/[(I +)+(I −)] (Parsons et al., 2013 ▸)
Absolute structure parameter	0.5 (6)

Computer programs: APEX2 and SAINT (Bruker, 2014 ▸), SHELXT2014 (Sheldrick, 2015a ▸), SHELXL2014 (Sheldrick, 2015b ▸), SHELXTL (Sheldrick, 2008 ▸), WinGX (Farrugia, 2012 ▸), Mercury (Macrae et al., 2006 ▸) and publCIF (Westrip, 2010 ▸).

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S2056989018012495/vm2211sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989018012495/vm2211Isup2.hkl

Click here for additional data file.

Supporting information file. DOI: 10.1107/S2056989018012495/vm2211Isup3.cml

CCDC reference: 1865811

Additional supporting information: crystallographic information; 3D view; checkCIF report

C10H10O4	F(000) = 204
Mr = 194.18	Dx = 1.496 Mg m−3
Monoclinic, P21	Mo Kα radiation, λ = 0.71073 Å
a = 5.251 (2) Å	Cell parameters from 2083 reflections
b = 6.317 (2) Å	θ = 3.1–27.5°
c = 12.999 (5) Å	µ = 0.12 mm−1
β = 91.643 (4)°	T = 100 K
V = 431.0 (3) Å3	Prism, yellow
Z = 2	0.38 × 0.30 × 0.13 mm

Bruker APEXII CCD diffractometer	1228 independent reflections
Radiation source: fine-focus sealed tube	1207 reflections with I > 2σ(I)
Detector resolution: 8.3333 pixels mm-1	Rint = 0.014
φ and ω scans	θmax = 27.5°, θmin = 1.6°
Absorption correction: multi-scan (SADABS; Bruker, 2001)	h = −6→6
Tmin = 0.785, Tmax = 0.785	k = −3→8
2328 measured reflections	l = −16→16

Refinement on F2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F2 > 2σ(F2)] = 0.029	w = 1/[σ2(Fo2) + (0.0523P)2 + 0.0966P] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.082	(Δ/σ)max < 0.001
S = 1.06	Δρmax = 0.25 e Å−3
1228 reflections	Δρmin = −0.22 e Å−3
131 parameters	Absolute structure: Flack x determined using 179 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons et al., 2013)
1 restraint	Absolute structure parameter: 0.5 (6)

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

	x	y	z	Uiso*/Ueq
O4	0.7944 (2)	0.8239 (2)	0.27690 (9)	0.0183 (3)
H4	0.7357	0.8998	0.3237	0.027*
O2	−0.0040 (2)	0.1772 (2)	0.38214 (9)	0.0193 (3)
O1	0.5175 (2)	0.9141 (2)	0.42970 (9)	0.0190 (3)
O3	0.2530 (2)	0.0865 (2)	0.21917 (9)	0.0174 (3)
H3	0.1418	0.0689	0.2635	0.026*
C3	0.5775 (3)	0.3220 (3)	0.17026 (11)	0.0136 (3)
C8	0.1144 (3)	0.3446 (3)	0.38843 (12)	0.0150 (4)
H8	0.0717	0.4408	0.4414	0.018*
C4	0.7113 (3)	0.5092 (3)	0.18410 (12)	0.0133 (3)
C1	0.3173 (3)	0.4049 (3)	0.31924 (12)	0.0128 (3)
C2	0.3797 (3)	0.2696 (3)	0.23855 (12)	0.0129 (3)
C7	0.3981 (3)	0.7489 (3)	0.41517 (12)	0.0153 (4)
H7	0.2619	0.7174	0.4592	0.018*
C5	0.6521 (3)	0.6468 (3)	0.26629 (12)	0.0134 (4)
C6	0.4550 (3)	0.5985 (3)	0.33345 (12)	0.0125 (3)
C9	0.6387 (3)	0.1702 (3)	0.08493 (12)	0.0177 (4)
H9A	0.6259	0.2441	0.0187	0.027*
H9B	0.5177	0.0521	0.0848	0.027*
H9C	0.8122	0.1159	0.0958	0.027*
C10	0.9192 (3)	0.5739 (3)	0.11251 (13)	0.0179 (4)
H10A	1.0138	0.4482	0.0915	0.027*
H10B	1.0356	0.6726	0.1481	0.027*
H10C	0.8431	0.6429	0.0515	0.027*

	U11	U22	U33	U12	U13	U23
O4	0.0187 (6)	0.0167 (7)	0.0198 (6)	−0.0064 (6)	0.0074 (5)	−0.0031 (5)
O2	0.0174 (5)	0.0194 (6)	0.0214 (6)	−0.0060 (6)	0.0049 (4)	−0.0018 (5)
O1	0.0228 (6)	0.0164 (6)	0.0180 (5)	−0.0036 (6)	0.0033 (5)	−0.0035 (5)
O3	0.0179 (5)	0.0158 (6)	0.0186 (6)	−0.0052 (6)	0.0051 (4)	−0.0035 (5)
C3	0.0127 (7)	0.0166 (8)	0.0117 (7)	0.0021 (7)	0.0015 (6)	−0.0001 (7)
C8	0.0130 (7)	0.0172 (9)	0.0148 (7)	−0.0010 (7)	0.0022 (6)	0.0000 (7)
C4	0.0108 (6)	0.0163 (8)	0.0130 (7)	0.0007 (6)	0.0024 (5)	0.0020 (7)
C1	0.0109 (6)	0.0151 (8)	0.0123 (6)	0.0000 (7)	0.0009 (5)	0.0007 (7)
C2	0.0115 (6)	0.0128 (9)	0.0144 (7)	−0.0017 (6)	0.0000 (6)	0.0010 (6)
C7	0.0162 (7)	0.0154 (8)	0.0142 (7)	0.0003 (7)	0.0018 (6)	0.0012 (7)
C5	0.0114 (6)	0.0151 (9)	0.0137 (7)	−0.0014 (7)	0.0001 (5)	0.0011 (7)
C6	0.0115 (6)	0.0139 (8)	0.0120 (7)	0.0001 (6)	0.0011 (5)	0.0011 (7)
C9	0.0185 (7)	0.0192 (9)	0.0157 (7)	0.0000 (7)	0.0034 (6)	−0.0048 (7)
C10	0.0146 (7)	0.0227 (9)	0.0166 (7)	−0.0003 (7)	0.0062 (6)	0.0012 (7)

O4—C5	1.350 (2)	C4—C10	1.511 (2)
O4—H4	0.84	C1—C2	1.399 (2)
O2—C8	1.228 (2)	C1—C6	1.431 (2)
O1—C7	1.229 (2)	C7—C6	1.462 (2)
O3—C2	1.354 (2)	C7—H7	0.95
O3—H3	0.84	C5—C6	1.406 (2)
C3—C4	1.385 (3)	C9—H9A	0.98
C3—C2	1.424 (2)	C9—H9B	0.98
C3—C9	1.508 (2)	C9—H9C	0.98
C8—C1	1.464 (2)	C10—H10A	0.98
C8—H8	0.95	C10—H10B	0.98
C4—C5	1.419 (2)	C10—H10C	0.98
C5—O4—H4	109.5	C6—C7—H7	118.4
C2—O3—H3	109.5	O4—C5—C6	122.08 (14)
C4—C3—C2	119.60 (14)	O4—C5—C4	116.85 (13)
C4—C3—C9	121.36 (14)	C6—C5—C4	121.06 (16)
C2—C3—C9	119.04 (16)	C5—C6—C1	118.92 (14)
O2—C8—C1	123.97 (16)	C5—C6—C7	118.66 (16)
O2—C8—H8	118.0	C1—C6—C7	122.42 (13)
C1—C8—H8	118.0	C3—C9—H9A	109.5
C3—C4—C5	119.97 (14)	C3—C9—H9B	109.5
C3—C4—C10	121.60 (15)	H9A—C9—H9B	109.5
C5—C4—C10	118.43 (17)	C3—C9—H9C	109.5
C2—C1—C6	119.38 (13)	H9A—C9—H9C	109.5
C2—C1—C8	119.46 (16)	H9B—C9—H9C	109.5
C6—C1—C8	121.15 (15)	C4—C10—H10A	109.5
O3—C2—C1	122.45 (14)	C4—C10—H10B	109.5
O3—C2—C3	116.47 (14)	H10A—C10—H10B	109.5
C1—C2—C3	121.05 (16)	C4—C10—H10C	109.5
O1—C7—C6	123.30 (15)	H10A—C10—H10C	109.5
O1—C7—H7	118.4	H10B—C10—H10C	109.5
C2—C3—C4—C5	0.4 (2)	C3—C4—C5—O4	178.32 (14)
C9—C3—C4—C5	−178.85 (15)	C10—C4—C5—O4	−2.5 (2)
C2—C3—C4—C10	−178.81 (15)	C3—C4—C5—C6	−1.3 (2)
C9—C3—C4—C10	2.0 (2)	C10—C4—C5—C6	177.94 (14)
O2—C8—C1—C2	1.9 (2)	O4—C5—C6—C1	−178.18 (14)
O2—C8—C1—C6	−177.34 (15)	C4—C5—C6—C1	1.4 (2)
C6—C1—C2—O3	−178.32 (13)	O4—C5—C6—C7	2.0 (2)
C8—C1—C2—O3	2.5 (2)	C4—C5—C6—C7	−178.41 (15)
C6—C1—C2—C3	−0.2 (2)	C2—C1—C6—C5	−0.6 (2)
C8—C1—C2—C3	−179.44 (14)	C8—C1—C6—C5	178.56 (15)
C4—C3—C2—O3	178.56 (14)	C2—C1—C6—C7	179.16 (16)
C9—C3—C2—O3	−2.2 (2)	C8—C1—C6—C7	−1.6 (2)
C4—C3—C2—C1	0.4 (2)	O1—C7—C6—C5	−1.6 (2)
C9—C3—C2—C1	179.61 (14)	O1—C7—C6—C1	178.61 (14)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3···O2	0.84	1.87	2.6079 (19)	146
O4—H4···O1	0.84	1.82	2.5592 (19)	146
O3—H3···O4i	0.84	2.40	3.036 (2)	133
O4—H4···O2ii	0.84	2.34	2.809 (2)	116
C7—H7···O2iii	0.95	2.51	3.427 (2)	162
C10—H10···Cg1iv	0.98	3.13	3.645	114