Download citation
Download citation
link to html
The title compound, C17H24O4, crystallizes with two independent mol­ecules, both lying across twofold rotation axes in space group Pccn, in a unit cell whose dimensions closely mimic those of a tetragonal cell. Each mol­ecule contains paired O—H...O hydrogen bonds [H...O = 1.81 and 1.83 Å, O...O = 2.640 (2) and 2.642 (2) Å, and O—H...O = 168 and 162°].

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270103023606/na1621sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270103023606/na1621Isup2.hkl
Contains datablock I

CCDC reference: 229094

Comment top

The structure of 2,2'-methylenebis(3-hydroxy-2-cyclohexen-1-one), (I), has recently been the subject of a brief report (SethuSankar et al., 2000), although the molecular constitution is incorrectly depicted in that report. This compound crystallizes in space group Pbca with Z' = 1, and the molecular structure is characterized by two rather short intramolecular hydrogen bonds.

We report here the structure of a tetramethyl analogue of (I), namely 2,2'-methylenebis(3-hydroxy-5,5-dimethylcyclohex-2-en-1-one), (II), originally obtained in low yield as an unexpected by-product in a three-component reaction between 2-methoxy 4-aminopyrimidin-6(1H)-one, formaldehyde and 5,5-dimethylcyclohexane-1,3-dione (dimedone), which had been intended to produce a tricyclic octahydropyrimido[3,4-b]quinoline system. Compound (II) was subsequently obtained in ca 70% yield by reaction of dimedone with aqueous formaldehyde in a reaction analogous to that used for the synthesis of compound (I) (SethuSankar et al., 2000). Compound (II) crystallizes in the orthorhombic space group Pccn; there are two independent molecules in the cell, each lying across a twofold rotation axis, so that Z' = 2 × 0.5 = 1. In the selected asymmetric unit, molecule 1 containing C1 (Fig. 1a) lies across the axis along (3/4, 1/4, z), while molecule 2 containing C2 (Fig. 1 b) lies across the axis (1/4, 1/4, z). The metric unit cell very closely mimics a tetragonal cell with the a and b repeat vectors differing by only ca 0.002 Å. However, the refined structure is clearly orthorhombic, although subject to twinning across the (110) plane; a search for possible additional symmetry revealed none, and the arrangement of the molecules in the unit cell (Fig. 2) clearly rules out the possibility of any kind of fourfold axis.

The two independent molecules are both chiral, with molecular symmetry C2, but the space group ensures that for each there are equal numbers of the two enantiomorphs present in the crystal. The two molecules in the selected asymmetric unit are in fact of opposite hand, as shown qualitatively by their overall configurations (Fig. 1) and quantitatively both by the key torsion angles (Table 1) and, better, by the ring-puckering parameters. For the independent rings C11–C16 and C21–C26, the overall puckering amplitudes Q (Cremer & Pople, 1975) are identical within experimental uncertainty, viz. 0.457 (3) and 0.459 (3) Å, respectively, but for the atom sequences Cn1 to Cn6 (n = 1 or 2), the θ values are 59.0 (3) and 119.8 (3)°, respectively, and the supplementary nature of these values defines different absolute configurations for the two molecules (Boeyens, 1978). The ϕ values, based on the same atom sequences for the rings C11–C16 and C21–C26, are 178.5 (4) and 0.9 (6)°, respectively, and the ring-puckering parameters taken together indicate a sofa or envelope conformation as the best single qualitative descriptor, with local pseudo-mirror planes in each ring, passing through the atoms Cn1 and Cn4.

Within the molecules, the C—C and C—O distances within the On2—Cn2—Cn1—Cn6—On6 (n = 1 or 2) fragments are clearly indicative of alternating single and double bonds, and they are consistent with the location of the associated H atoms, as located from difference maps. The remaining bond distances and angles show no unusual values. In each molecule, there are two fairly short O—H···O hydrogen bonds (Table 2), which probably play a role in controlling the overall molecular conformation, in particular, in constraining the molecules to have overall twofold rotational symmetry.

There are, however, no direction-specific interactions between the molecules of (II). In particular, there are no C—H···O hydrogen bonds; the shortest intermolecular H···O contact distance is not significantly less than the the sum of the van der Waals radii. In compound (I), a number of intermolecular C—H···O contacts were reported as hydrogen bonds (SethuSankar et al., 2000), but in every case the H···O distance exceeds 2.55 Å (the overall range reported was 2.56–2.71 Å), so that it is doubtful if these contacts are structurally significant.

Experimental top

To a solution of 2-methoxy-4-aminopyrimidin-6(1H)-one (2.12 mmol) and dimedone (1.92 mmol) in ethanol (30 ml) was added a large excess (26.5 mmol) of formaldehyde (35% aqueous solution). The mixture was then heated under reflux for 2 h and the resulting white solid was filtered off and washed with cold ethyl acetate and then with ethanol. This product was purified crystallization firstly from ethanol/water (9:1, v/v) and then from N,N-dimethylformamide, giving, in very low yield, crystals of the title compound, (II), suitable for single-crystal X-ray diffraction analysis. M.p. 463 K. Analysis found: C 69.5, H 8.5%; C17H24O4 requires C 69.8, H, 8.3%. The same product was obtained in ca 70% yield in the absence of the pyrimidinone. To a solution of dimedone (2 mmol) in ethanol (10 ml) was added formaldehyde (35% aqueous solution, 1 mmol). The mixture was stirred at room temperature for 2 h and then left to evaporate at atmospheric pressure, producing (II).

Refinement top

Space group Pccn was uniquely assigned from the systematic absences. All H atoms were located from difference maps and then treated as riding atoms, with C—H = 0.98 (CH3) or 0.99 Å (CH2), and O—H = 0.84 Å. A TWIN refinement using the matrix (010/100/001) gave twin fractions 0.468 and 0.532. Examination of the refined structure using the ADDSYM option in PLATON (Spek, 2003) revealed no possible additional symmetry.

Computing details top

Data collection: KappaCCD Server Software (Nonius, 1997); cell refinement: DENZO-SMN (Otwinowski & Minor, 1997); data reduction: DENZO-SMN; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97 and PRPKAPPA (Ferguson, 1999).

Figures top
[Figure 1] Fig. 1. The two independent molecules of compound (II), showing the atom-labelling scheme for (a) molecule 1 and (b) molecule 2. Displacement ellipsoids are drawn at the 30% probability level.
[Figure 2] Fig. 2. Stereoview of part of the crystal structure of (II), showing how the packing of the molecules precludes tetragonal symmetry. For the sake of clarity, the H atoms have been omitted.
2,2'-Methylenebis(3-hydroxy-5,5-dimethylcyclohex-2-en-1-one) top
Crystal data top
C17H24O4F(000) = 1264
Mr = 292.36Dx = 1.249 Mg m3
Orthorhombic, PccnMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ab 2acCell parameters from 3552 reflections
a = 18.8968 (4) Åθ = 3.1–27.5°
b = 18.8989 (4) ŵ = 0.09 mm1
c = 8.7038 (2) ÅT = 120 K
V = 3108.38 (12) Å3Block, colourless
Z = 80.22 × 0.20 × 0.10 mm
Data collection top
Nonius KappaCCD
diffractometer
3552 independent reflections
Radiation source: fine-focus sealed X-ray tube2991 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.080
ϕ scans, and ω scans with κ offsetsθmax = 27.5°, θmin = 3.1°
Absorption correction: multi-scan
(DENZO-SMN; Otwinowski & Minor, 1997)
h = 2420
Tmin = 0.973, Tmax = 0.991k = 2424
22526 measured reflectionsl = 911
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.047H-atom parameters constrained
wR(F2) = 0.116 w = 1/[σ2(Fo2) + (0.0453P)2 + 1.0196P]
where P = (Fo2 + 2Fc2)/3
S = 1.03(Δ/σ)max < 0.001
3553 reflectionsΔρmax = 0.20 e Å3
199 parametersΔρmin = 0.22 e Å3
0 restraintsExtinction correction: SHELXL, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.0104 (13)
Crystal data top
C17H24O4V = 3108.38 (12) Å3
Mr = 292.36Z = 8
Orthorhombic, PccnMo Kα radiation
a = 18.8968 (4) ŵ = 0.09 mm1
b = 18.8989 (4) ÅT = 120 K
c = 8.7038 (2) Å0.22 × 0.20 × 0.10 mm
Data collection top
Nonius KappaCCD
diffractometer
3552 independent reflections
Absorption correction: multi-scan
(DENZO-SMN; Otwinowski & Minor, 1997)
2991 reflections with I > 2σ(I)
Tmin = 0.973, Tmax = 0.991Rint = 0.080
22526 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0470 restraints
wR(F2) = 0.116H-atom parameters constrained
S = 1.03Δρmax = 0.20 e Å3
3553 reflectionsΔρmin = 0.22 e Å3
199 parameters
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
O120.82227 (7)0.37084 (8)0.05384 (19)0.0267 (4)
O160.60706 (8)0.24787 (9)0.0998 (2)0.0311 (4)
O220.37273 (8)0.32308 (8)0.0600 (2)0.0297 (4)
O260.24828 (8)0.10777 (8)0.0809 (2)0.0328 (4)
C10.75000.25000.1933 (3)0.0215 (6)
C110.71545 (10)0.30849 (11)0.1003 (2)0.0207 (5)
C120.75209 (12)0.36453 (12)0.0430 (2)0.0227 (5)
C130.71854 (12)0.42409 (12)0.0421 (3)0.0243 (5)
C140.63961 (14)0.43466 (16)0.0039 (3)0.0240 (6)
C1410.63120 (12)0.46509 (13)0.1569 (3)0.0300 (5)
C1420.60627 (12)0.48499 (13)0.1213 (3)0.0305 (5)
C150.60352 (13)0.36177 (13)0.0150 (3)0.0249 (6)
C160.64091 (11)0.30284 (11)0.0678 (3)0.0226 (5)
C20.25000.25000.1851 (3)0.0231 (6)
C210.30897 (10)0.21603 (11)0.0938 (2)0.0220 (5)
C220.36689 (11)0.25365 (13)0.0441 (3)0.0224 (5)
C230.42898 (12)0.22030 (13)0.0335 (3)0.0250 (5)
C240.43625 (15)0.14089 (15)0.0001 (2)0.0237 (6)
C2410.49082 (13)0.10933 (13)0.1119 (3)0.0324 (6)
C2420.46207 (12)0.12918 (13)0.1656 (3)0.0296 (6)
C250.36430 (12)0.10614 (14)0.0242 (3)0.0258 (6)
C260.30390 (12)0.14283 (12)0.0548 (2)0.0247 (5)
H120.83960.33260.08540.040*
H220.33250.34070.07540.044*
H1A0.78640.27150.26060.026*0.50
H1B0.71360.22850.26060.026*0.50
H13A0.72340.41530.15370.029*
H13B0.74440.46830.01800.029*
H14A0.58090.47310.17820.045*
H14B0.65690.51000.16400.045*
H14C0.65040.43170.23230.045*
H14D0.55550.48960.10030.046*
H14E0.61310.46600.22510.046*
H14F0.62880.53150.11370.046*
H15A0.55500.36590.02680.030*
H15B0.59940.34880.12490.030*
H2A0.27110.28660.25250.028*0.50
H2B0.22890.21340.25250.028*0.50
H23A0.47270.24470.00030.030*
H23B0.42450.22720.14580.030*
H24A0.49570.05850.09230.049*
H24B0.53660.13260.09690.049*
H24C0.47480.11680.21780.049*
H24D0.42590.14590.23780.044*
H24E0.50610.15560.18210.044*
H24F0.47070.07860.18240.044*
H25A0.35430.10450.13590.031*
H25B0.36670.05670.01320.031*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O120.0179 (8)0.0255 (9)0.0369 (10)0.0008 (6)0.0006 (7)0.0021 (7)
O160.0196 (8)0.0258 (9)0.0479 (10)0.0016 (6)0.0034 (7)0.0055 (7)
O220.0229 (8)0.0219 (9)0.0442 (10)0.0014 (6)0.0028 (8)0.0014 (8)
O260.0220 (9)0.0245 (9)0.0520 (12)0.0038 (6)0.0034 (7)0.0017 (7)
C10.0196 (15)0.0243 (16)0.0206 (14)0.0015 (11)0.0000.000
C110.0202 (11)0.0224 (12)0.0194 (10)0.0012 (8)0.0006 (8)0.0028 (8)
C120.0199 (11)0.0270 (12)0.0211 (10)0.0015 (8)0.0007 (9)0.0039 (9)
C130.0249 (12)0.0226 (12)0.0252 (11)0.0012 (9)0.0027 (9)0.0003 (10)
C140.0235 (16)0.0216 (17)0.0269 (12)0.0017 (11)0.0005 (8)0.0008 (8)
C1410.0262 (12)0.0283 (13)0.0355 (13)0.0026 (9)0.0030 (9)0.0036 (10)
C1420.0299 (13)0.0260 (13)0.0358 (12)0.0015 (9)0.0032 (10)0.0063 (10)
C150.0189 (12)0.0252 (14)0.0306 (12)0.0002 (10)0.0025 (9)0.0017 (9)
C160.0209 (11)0.0233 (12)0.0235 (11)0.0010 (8)0.0019 (8)0.0002 (8)
C20.0245 (15)0.0239 (16)0.0209 (15)0.0018 (11)0.0000.000
C210.0193 (11)0.0238 (12)0.0228 (11)0.0012 (8)0.0013 (8)0.0021 (8)
C220.0191 (11)0.0211 (12)0.0271 (12)0.0006 (8)0.0065 (9)0.0037 (10)
C230.0213 (11)0.0256 (13)0.0281 (12)0.0015 (9)0.0015 (9)0.0014 (10)
C240.0217 (16)0.0209 (15)0.0286 (12)0.0014 (11)0.0010 (8)0.0002 (8)
C2410.0281 (13)0.0322 (13)0.0368 (14)0.0032 (9)0.0022 (10)0.0034 (10)
C2420.0267 (12)0.0306 (13)0.0315 (12)0.0012 (10)0.0047 (9)0.0047 (9)
C250.0210 (13)0.0246 (14)0.0319 (13)0.0003 (10)0.0002 (9)0.0011 (9)
C260.0199 (11)0.0275 (12)0.0268 (11)0.0015 (9)0.0022 (8)0.0041 (9)
Geometric parameters (Å, º) top
O12—C121.335 (3)C142—H14E0.98
C12—C111.360 (3)C142—H14F0.98
C11—C161.441 (3)C15—C161.503 (3)
C16—O161.251 (3)C15—H15A0.99
O12—H120.84C15—H15B0.99
O22—C221.324 (3)C2—C211.512 (2)
C22—C211.375 (3)C2—C21ii1.512 (2)
C21—C261.428 (3)C2—H2A0.99
C26—O261.263 (3)C2—H2B0.99
O22—H220.84C22—C231.493 (3)
C1—C11i1.518 (2)C23—C241.535 (4)
C1—C111.518 (2)C23—H23A0.99
C1—H1A0.99C23—H23B0.99
C1—H1B0.99C24—C251.525 (4)
C12—C131.489 (3)C24—C2421.537 (3)
C13—C141.541 (4)C24—C2411.539 (3)
C13—H13A0.99C241—H24A0.98
C13—H13B0.99C241—H24B0.98
C14—C1411.522 (3)C241—H24C0.98
C14—C1421.532 (4)C242—H24D0.98
C14—C151.540 (4)C242—H24E0.98
C141—H14A0.98C242—H24F0.98
C141—H14B0.98C25—C261.502 (3)
C141—H14C0.98C25—H25A0.99
C142—H14D0.98C25—H25B0.99
C12—O12—H12109.5C11—C16—C15119.93 (19)
C22—O22—H22109.5C21—C2—C21ii116.6 (2)
C11i—C1—C11115.6 (2)C21—C2—H2A108.1
C11i—C1—H1A108.4C21ii—C2—H2A108.1
C11—C1—H1A108.4C21—C2—H2B108.1
C11i—C1—H1B108.4C21ii—C2—H2B108.1
C11—C1—H1B108.4H2A—C2—H2B107.3
H1A—C1—H1B107.5C22—C21—C26118.7 (2)
C12—C11—C16118.92 (19)C22—C21—C2122.18 (18)
C12—C11—C1122.93 (17)C26—C21—C2119.15 (16)
C16—C11—C1118.13 (16)O22—C22—C21123.1 (2)
O12—C12—C11123.3 (2)O22—C22—C23113.6 (2)
O12—C12—C13112.98 (19)C21—C22—C23123.3 (2)
C11—C12—C13123.6 (2)C22—C23—C24113.37 (19)
C12—C13—C14113.76 (19)C22—C23—H23A108.9
C12—C13—H13A108.8C24—C23—H23A108.9
C14—C13—H13A108.8C22—C23—H23B108.9
C12—C13—H13B108.8C24—C23—H23B108.9
C14—C13—H13B108.8H23A—C23—H23B107.7
H13A—C13—H13B107.7C25—C24—C23108.3 (2)
C141—C14—C142109.6 (2)C25—C24—C242110.6 (2)
C141—C14—C15110.5 (2)C23—C24—C242110.3 (2)
C142—C14—C15109.4 (2)C25—C24—C241110.0 (2)
C141—C14—C13110.37 (19)C23—C24—C241108.6 (2)
C142—C14—C13109.57 (19)C242—C24—C241109.0 (2)
C15—C14—C13107.4 (2)C24—C241—H24A109.5
C14—C141—H14A109.5C24—C241—H24B109.5
C14—C141—H14B109.5H24A—C241—H24B109.5
H14A—C141—H14B109.5C24—C241—H24C109.5
C14—C141—H14C109.5H24A—C241—H24C109.5
H14A—C141—H14C109.5H24B—C241—H24C109.5
H14B—C141—H14C109.5C24—C242—H24D109.5
C14—C142—H14D109.5C24—C242—H24E109.5
C14—C142—H14E109.5H24D—C242—H24E109.5
H14D—C142—H14E109.5C24—C242—H24F109.5
C14—C142—H14F109.5H24D—C242—H24F109.5
H14D—C142—H14F109.5H24E—C242—H24F109.5
H14E—C142—H14F109.5C26—C25—C24114.5 (2)
C16—C15—C14115.11 (19)C26—C25—H25A108.6
C16—C15—H15A108.5C24—C25—H25A108.6
C14—C15—H15A108.5C26—C25—H25B108.6
C16—C15—H15B108.5C24—C25—H25B108.6
C14—C15—H15B108.5H25A—C25—H25B107.6
H15A—C15—H15B107.5O26—C26—C21121.4 (2)
O16—C16—C11121.16 (19)O26—C26—C25118.2 (2)
O16—C16—C15118.79 (18)C21—C26—C25120.4 (2)
C1—C11—C12—O124.8 (3)C26—C21—C22—O22172.5 (2)
C1—C11—C16—O167.9 (3)C2—C21—C22—O226.2 (3)
C11i—C1—C11—C1283.8 (2)C2—C21—C26—O267.4 (3)
C11i—C1—C11—C1694.2 (2)C21ii—C2—C21—C2287.2 (2)
C16—C11—C12—O12173.2 (2)C21ii—C2—C21—C2691.4 (2)
C16—C11—C12—C135.0 (3)C26—C21—C22—C237.2 (3)
C1—C11—C12—C13177.01 (19)C2—C21—C22—C23174.2 (2)
O12—C12—C13—C14157.34 (19)O22—C22—C23—C24158.53 (19)
C11—C12—C13—C1424.3 (3)C21—C22—C23—C2421.8 (3)
C12—C13—C14—C14171.8 (3)C22—C23—C24—C2548.2 (3)
C12—C13—C14—C142167.4 (2)C22—C23—C24—C24273.0 (3)
C12—C13—C14—C1548.7 (2)C22—C23—C24—C241167.7 (2)
C141—C14—C15—C1672.1 (3)C23—C24—C25—C2649.4 (3)
C142—C14—C15—C16167.1 (2)C242—C24—C25—C2671.7 (3)
C13—C14—C15—C1648.3 (3)C241—C24—C25—C26167.9 (2)
C12—C11—C16—O16170.2 (2)C22—C21—C26—O26171.3 (2)
C12—C11—C16—C155.8 (3)C22—C21—C26—C256.4 (3)
C1—C11—C16—C15176.1 (2)C2—C21—C26—C25174.9 (2)
C14—C15—C16—O16161.0 (2)C24—C25—C26—O26158.7 (2)
C14—C15—C16—C1122.8 (3)C24—C25—C26—C2123.5 (3)
Symmetry codes: (i) x+3/2, y+1/2, z; (ii) x+1/2, y+1/2, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O12—H12···O16i0.841.832.642 (2)162
O22—H22···O26ii0.841.812.640 (2)168
Symmetry codes: (i) x+3/2, y+1/2, z; (ii) x+1/2, y+1/2, z.

Experimental details

Crystal data
Chemical formulaC17H24O4
Mr292.36
Crystal system, space groupOrthorhombic, Pccn
Temperature (K)120
a, b, c (Å)18.8968 (4), 18.8989 (4), 8.7038 (2)
V3)3108.38 (12)
Z8
Radiation typeMo Kα
µ (mm1)0.09
Crystal size (mm)0.22 × 0.20 × 0.10
Data collection
DiffractometerNonius KappaCCD
diffractometer
Absorption correctionMulti-scan
(DENZO-SMN; Otwinowski & Minor, 1997)
Tmin, Tmax0.973, 0.991
No. of measured, independent and
observed [I > 2σ(I)] reflections
22526, 3552, 2991
Rint0.080
(sin θ/λ)max1)0.649
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.047, 0.116, 1.03
No. of reflections3553
No. of parameters199
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.20, 0.22

Computer programs: KappaCCD Server Software (Nonius, 1997), DENZO-SMN (Otwinowski & Minor, 1997), DENZO-SMN, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), PLATON (Spek, 2003), SHELXL97 and PRPKAPPA (Ferguson, 1999).

Selected geometric parameters (Å, º) top
O12—C121.335 (3)O22—C221.324 (3)
C12—C111.360 (3)C22—C211.375 (3)
C11—C161.441 (3)C21—C261.428 (3)
C16—O161.251 (3)C26—O261.263 (3)
C1—C11—C12—O124.8 (3)C2—C21—C22—O226.2 (3)
C1—C11—C16—O167.9 (3)C2—C21—C26—O267.4 (3)
C11i—C1—C11—C1283.8 (2)C21ii—C2—C21—C2287.2 (2)
C11i—C1—C11—C1694.2 (2)C21ii—C2—C21—C2691.4 (2)
Symmetry codes: (i) x+3/2, y+1/2, z; (ii) x+1/2, y+1/2, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O12—H12···O16i0.841.832.642 (2)162
O22—H22···O26ii0.841.812.640 (2)168
Symmetry codes: (i) x+3/2, y+1/2, z; (ii) x+1/2, y+1/2, z.
 

Follow Acta Cryst. C
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds