supplementary materials


fy2087 scheme

Acta Cryst. (2013). E69, o734    [ doi:10.1107/S1600536813009872 ]

(1R*,2R*,3S*,4R*)-Diethyl 4-hydroxy-4-methyl-2-(4-methylphenyl)-6-oxocyclohexane-1,3-dicarboxylate

A. I. Ismiev, N. A. Gadirova, K. E. Hajiyeva, R. K. Askerov and K. A. Potekhin

Abstract top

The title compound, C20H26O6, is chiral and crystallizes as a racemate: the relative configuration of the stereogenic centres is 1R*,2R*,3S*,4R*. The cyclohexane ring has a chair conformation. The ethyl fragment of the ethoxycarbonyl group in the 3-position is disordered over two sets of sites in a 0.650 (6):0.350 (6) ratio. The hydroxy group acts as a bifurcated hydrogen-bond donor, forming both intra- and intermolecular hydrogen bonds with ester carbonyl O atoms. The intermolecular hydrogen bonds form inversion dimers in the crystal.

Comment top

The relative arrangement of functional groups in polyfunctional diethoxycarbonyl substituted cyclohexane β-ketols renders them favorable intermediates for the construction of enamines and nitrogen heterocyclic compounds (Gein et al., 2003; Gein et al., 2004; Sorokin et al., 2000). From our point of view, it is important to determine the molecular crystal structure of the initial β-ketols to aid the exploration of heterocyclization reactions.

Fig. 1 shows the molecular structure of title compound (I) C20H26O6. The cyclohexane ring has a chair conformation (Fig. 2). Four atoms of the cyclohexane ring, C2, C3, C5 and C6 are located on the same plane [r.m.s deviation = 0.011 (2) Å], while C1 [deviation = 0.617 (2) Å] and C4 [deviation = -0.698 (2) Å] deviate from the plane. The ethyl fragment of the ethoxycarbonyl group at the position of C3 is disordered over two sets of sites in a 0.650 (6):0.350 (6) ratio. The OH group participates in the formation of both intramolecular and intermolecular hydrogen bonds. The intermolecular hydrogen bonds form centrosymmetric dimers. These dimers form stacks in the direction of the axis a (Fig. 3). The stacking of dimers is governed by van der Waals interactions.

Related literature top

For applications of related compounds as synthetic intermediates, see: Gein et al. (2003, 2004); Sorokin et al. (2000).

Experimental top

4-methyl benzaldehyde (10 mmol) and acetoacetic ester (20 mmol) were dissolved in 20 ml ethanol. 1 ml piperidine was added to the reaction mixture. After 48 h the obtained crystals were filtered and washed with ethanol. The crystals were dissolved in ethanol (50 ml) and recrystallized by slow solvent evaporation to yield the crystals of the title compound suitable for X-ray analysis.

Refinement top

The hydrogen atom of the OH group was found in a difference Fourier map and was included in the refinement with isotropic displacement parameters. The other hydrogen atoms were placed in calculated positions with C—H distances of 0.93–0.98 Å and were refined in the riding mode with fixed isotropic displacement parameters [Uiso(H) = 1.2 Ueq(C) or 1.5Ueq(C) for methyl H atoms]. The C—C and C—O bond distances of the disordered ethoxy group were restrained to 1.540 (4) and 1.453 (4) Å, respectively.

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT-Plus (Bruker, 2001); data reduction: SAINT-Plus (Bruker, 2001); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. Molecular structure of the title compound with the atom numbering scheme. Displacement ellipsoids were drawn at the 30% probability level.
[Figure 2] Fig. 2. Perspective view of the dimer. H bonds are shown as a dashed lines. H atoms that not involved in the formation of hydrogen bonds are not shown.
[Figure 3] Fig. 3. Stacking of the dimers in the crystal lattice.
Diethyl 4-hydroxy-4-methyl-2-(4-methylphenyl)-6-oxocyclohexane-1,3-dicarboxylate top
Crystal data top
C20H26O6Z = 2
Mr = 362.41F(000) = 388
Triclinic, P1Dx = 1.209 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 5.8062 (4) ÅCell parameters from 2311 reflections
b = 9.9267 (7) Åθ = 2.2–24.0°
c = 18.4548 (13) ŵ = 0.09 mm1
α = 103.281 (2)°T = 296 K
β = 92.490 (2)°Prism, colourless
γ = 104.741 (2)°0.30 × 0.20 × 0.20 mm
V = 995.26 (12) Å3
Data collection top
Bruker APEXII CCD
diffractometer
4344 independent reflections
Radiation source: fine-focus sealed tube2735 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.024
φ and ω scansθmax = 27.0°, θmin = 2.2°
Absorption correction: multi-scan
(SADABS; Sheldrick, 2003)
h = 77
Tmin = 0.974, Tmax = 0.983k = 1212
10589 measured reflectionsl = 2323
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.053Hydrogen site location: difference Fourier map
wR(F2) = 0.141H atoms treated by a mixture of independent and constrained refinement
S = 1.01 w = 1/[σ2(Fo2) + (0.0532P)2 + 0.330P]
where P = (Fo2 + 2Fc2)/3
4344 reflections(Δ/σ)max < 0.001
245 parametersΔρmax = 0.30 e Å3
4 restraintsΔρmin = 0.28 e Å3
Crystal data top
C20H26O6γ = 104.741 (2)°
Mr = 362.41V = 995.26 (12) Å3
Triclinic, P1Z = 2
a = 5.8062 (4) ÅMo Kα radiation
b = 9.9267 (7) ŵ = 0.09 mm1
c = 18.4548 (13) ÅT = 296 K
α = 103.281 (2)°0.30 × 0.20 × 0.20 mm
β = 92.490 (2)°
Data collection top
Bruker APEXII CCD
diffractometer
4344 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 2003)
2735 reflections with I > 2σ(I)
Tmin = 0.974, Tmax = 0.983Rint = 0.024
10589 measured reflectionsθmax = 27.0°
Refinement top
R[F2 > 2σ(F2)] = 0.053H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.141Δρmax = 0.30 e Å3
S = 1.01Δρmin = 0.28 e Å3
4344 reflectionsAbsolute structure: ?
245 parametersFlack parameter: ?
4 restraintsRogers parameter: ?
Special details top

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
xyzUiso*/UeqOcc. (<1)
O10.4611 (3)0.07429 (19)0.06812 (9)0.0807 (6)
O20.1412 (3)0.13134 (16)0.12814 (9)0.0695 (5)
O31.0827 (2)0.24372 (16)0.31384 (8)0.0568 (4)
O40.8797 (3)0.31533 (17)0.40878 (8)0.0611 (4)
O50.8906 (3)0.48221 (18)0.26673 (11)0.0808 (6)
O60.6651 (3)0.23247 (18)0.09792 (9)0.0554 (4)
H60.628 (6)0.154 (4)0.058 (2)0.131 (14)*
C10.6833 (3)0.2564 (2)0.28710 (10)0.0416 (4)
H1A0.55230.25880.31870.050*
C20.6142 (3)0.10970 (19)0.22851 (10)0.0394 (4)
H2A0.75100.10380.19980.047*
C30.4002 (3)0.1013 (2)0.17338 (11)0.0434 (5)
H3A0.26200.10590.20150.052*
C40.4528 (3)0.2273 (2)0.13498 (11)0.0476 (5)
C50.5117 (4)0.3687 (2)0.19497 (12)0.0544 (5)
H5A0.55210.44810.17130.065*
H5B0.37150.37510.22080.065*
C60.7152 (4)0.3814 (2)0.25046 (12)0.0505 (5)
C70.3412 (4)0.0423 (2)0.11719 (12)0.0518 (5)
C80.0451 (13)0.2768 (4)0.0822 (3)0.1013 (17)0.650 (6)
H8A0.08970.28390.03170.122*0.650 (6)
H8B0.12830.30600.08000.122*0.650 (6)
C90.1545 (10)0.3702 (5)0.1203 (3)0.1013 (17)0.650 (6)
H9A0.09830.46860.09220.152*0.650 (6)
H9B0.10820.36180.17010.152*0.650 (6)
H9C0.32590.33890.12270.152*0.650 (6)
C8A0.1229 (14)0.2769 (5)0.0834 (5)0.062 (3)*0.350 (6)
H8AA0.26990.30260.09260.074*0.350 (6)
H8AB0.09840.28090.03050.074*0.350 (6)
C9A0.0872 (18)0.3816 (10)0.1050 (6)0.114 (4)*0.350 (6)
H9AA0.09890.47760.07670.171*0.350 (6)
H9AB0.23250.35700.09450.171*0.350 (6)
H9AC0.06260.37610.15750.171*0.350 (6)
C100.9053 (4)0.2708 (2)0.33654 (11)0.0439 (5)
C111.0701 (5)0.3137 (3)0.46185 (14)0.0761 (8)
H11A1.07080.38090.50930.091*
H11B1.22360.34340.44310.091*
C121.0331 (6)0.1658 (3)0.47313 (16)0.0921 (9)
H12A1.15120.16710.51150.138*
H12B1.04850.10140.42720.138*
H12C0.87600.13390.48790.138*
C130.5667 (3)0.01238 (19)0.26723 (10)0.0394 (4)
C140.3813 (4)0.0336 (2)0.31157 (12)0.0556 (6)
H14A0.28280.02790.31770.067*
C150.3402 (4)0.1444 (3)0.34675 (13)0.0616 (6)
H15A0.21360.15650.37590.074*
C160.4826 (4)0.2382 (2)0.33975 (12)0.0537 (5)
C170.6670 (4)0.2166 (2)0.29575 (13)0.0583 (6)
H17A0.76650.27750.29010.070*
C180.7080 (4)0.1061 (2)0.25972 (12)0.0504 (5)
H18A0.83320.09500.22990.060*
C190.4324 (5)0.3606 (3)0.37778 (15)0.0763 (8)
H19A0.56730.40000.37690.114*
H19B0.29280.43390.35190.114*
H19C0.40520.32550.42880.114*
C200.2422 (4)0.2159 (3)0.07980 (14)0.0680 (7)
H20A0.27700.29750.05850.102*
H20B0.10140.21370.10540.102*
H20C0.21520.12930.04070.102*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0936 (13)0.0774 (12)0.0587 (10)0.0147 (10)0.0294 (10)0.0019 (9)
O20.0692 (11)0.0619 (10)0.0632 (10)0.0041 (8)0.0070 (8)0.0117 (8)
O30.0440 (8)0.0673 (10)0.0644 (10)0.0212 (7)0.0064 (7)0.0197 (8)
O40.0712 (10)0.0678 (10)0.0452 (8)0.0292 (8)0.0008 (7)0.0059 (7)
O50.0744 (12)0.0503 (10)0.1131 (15)0.0027 (9)0.0191 (10)0.0327 (10)
O60.0469 (8)0.0681 (10)0.0568 (9)0.0153 (7)0.0161 (7)0.0252 (8)
C10.0396 (10)0.0436 (11)0.0444 (11)0.0158 (8)0.0069 (9)0.0115 (9)
C20.0366 (10)0.0442 (11)0.0411 (10)0.0150 (8)0.0085 (8)0.0125 (8)
C30.0371 (10)0.0528 (12)0.0425 (11)0.0145 (9)0.0088 (8)0.0132 (9)
C40.0410 (11)0.0609 (13)0.0480 (11)0.0189 (9)0.0079 (9)0.0214 (10)
C50.0567 (13)0.0541 (13)0.0635 (14)0.0258 (10)0.0082 (11)0.0244 (11)
C60.0521 (12)0.0430 (12)0.0590 (13)0.0179 (10)0.0044 (10)0.0123 (10)
C70.0535 (13)0.0589 (13)0.0417 (11)0.0127 (11)0.0041 (10)0.0132 (10)
C80.124 (4)0.071 (2)0.085 (3)0.003 (2)0.022 (2)0.0108 (17)
C90.124 (4)0.071 (2)0.085 (3)0.003 (2)0.022 (2)0.0108 (17)
C100.0479 (12)0.0353 (10)0.0490 (12)0.0122 (9)0.0044 (9)0.0105 (9)
C110.095 (2)0.0757 (18)0.0550 (14)0.0293 (15)0.0175 (14)0.0088 (13)
C120.127 (3)0.094 (2)0.0652 (17)0.0392 (19)0.0012 (17)0.0311 (16)
C130.0374 (10)0.0405 (10)0.0405 (10)0.0121 (8)0.0039 (8)0.0087 (8)
C140.0566 (13)0.0656 (14)0.0604 (13)0.0299 (11)0.0210 (11)0.0293 (11)
C150.0578 (14)0.0756 (16)0.0618 (14)0.0191 (12)0.0189 (11)0.0344 (13)
C160.0566 (13)0.0474 (12)0.0530 (13)0.0046 (10)0.0064 (11)0.0175 (10)
C170.0549 (13)0.0462 (12)0.0780 (16)0.0190 (10)0.0040 (12)0.0183 (11)
C180.0463 (11)0.0440 (11)0.0630 (13)0.0146 (9)0.0134 (10)0.0138 (10)
C190.0884 (19)0.0631 (16)0.0767 (17)0.0067 (14)0.0060 (15)0.0347 (14)
C200.0573 (14)0.0904 (18)0.0661 (15)0.0255 (13)0.0000 (12)0.0339 (14)
Geometric parameters (Å, º) top
O1—C71.200 (2)C9—H9C0.9600
O2—C71.323 (3)C8A—C9A1.522 (4)
O2—C81.449 (3)C8A—H8AA0.9700
O2—C8A1.465 (4)C8A—H8AB0.9700
O3—C101.198 (2)C9A—H9AA0.9600
O4—C101.332 (2)C9A—H9AB0.9600
O4—C111.450 (3)C9A—H9AC0.9600
O5—C61.203 (3)C11—C121.493 (4)
O6—C41.431 (2)C11—H11A0.9700
O6—H60.91 (4)C11—H11B0.9700
C1—C101.503 (3)C12—H12A0.9600
C1—C61.520 (3)C12—H12B0.9600
C1—C21.547 (3)C12—H12C0.9600
C1—H1A0.9800C13—C181.377 (3)
C2—C131.517 (3)C13—C141.383 (3)
C2—C31.544 (3)C14—C151.377 (3)
C2—H2A0.9800C14—H14A0.9300
C3—C71.505 (3)C15—C161.382 (3)
C3—C41.546 (3)C15—H15A0.9300
C3—H3A0.9800C16—C171.375 (3)
C4—C201.521 (3)C16—C191.511 (3)
C4—C51.524 (3)C17—C181.385 (3)
C5—C61.490 (3)C17—H17A0.9300
C5—H5A0.9700C18—H18A0.9300
C5—H5B0.9700C19—H19A0.9600
C8—C91.522 (4)C19—H19B0.9600
C8—H8A0.9700C19—H19C0.9600
C8—H8B0.9700C20—H20A0.9600
C9—H9A0.9600C20—H20B0.9600
C9—H9B0.9600C20—H20C0.9600
C7—O2—C8123.5 (4)O2—C8A—H8AB109.9
C7—O2—C8A109.3 (3)C9A—C8A—H8AB109.9
C10—O4—C11116.33 (18)H8AA—C8A—H8AB108.3
C4—O6—H6106 (2)C8A—C9A—H9AA109.5
C10—C1—C6111.07 (16)C8A—C9A—H9AB109.5
C10—C1—C2110.21 (14)H9AA—C9A—H9AB109.5
C6—C1—C2111.87 (16)C8A—C9A—H9AC109.5
C10—C1—H1A107.8H9AA—C9A—H9AC109.5
C6—C1—H1A107.8H9AB—C9A—H9AC109.5
C2—C1—H1A107.8O3—C10—O4124.06 (19)
C13—C2—C3113.00 (15)O3—C10—C1124.13 (18)
C13—C2—C1110.32 (15)O4—C10—C1111.80 (17)
C3—C2—C1109.93 (14)O4—C11—C12109.8 (2)
C13—C2—H2A107.8O4—C11—H11A109.7
C3—C2—H2A107.8C12—C11—H11A109.7
C1—C2—H2A107.8O4—C11—H11B109.7
C7—C3—C2107.99 (16)C12—C11—H11B109.7
C7—C3—C4111.78 (16)H11A—C11—H11B108.2
C2—C3—C4111.96 (15)C11—C12—H12A109.5
C7—C3—H3A108.3C11—C12—H12B109.5
C2—C3—H3A108.3H12A—C12—H12B109.5
C4—C3—H3A108.3C11—C12—H12C109.5
O6—C4—C20110.23 (17)H12A—C12—H12C109.5
O6—C4—C5104.60 (17)H12B—C12—H12C109.5
C20—C4—C5110.88 (18)C18—C13—C14117.48 (18)
O6—C4—C3110.68 (15)C18—C13—C2121.02 (17)
C20—C4—C3111.32 (17)C14—C13—C2121.50 (16)
C5—C4—C3108.92 (16)C15—C14—C13121.1 (2)
C6—C5—C4111.90 (16)C15—C14—H14A119.5
C6—C5—H5A109.2C13—C14—H14A119.5
C4—C5—H5A109.2C14—C15—C16121.7 (2)
C6—C5—H5B109.2C14—C15—H15A119.2
C4—C5—H5B109.2C16—C15—H15A119.2
H5A—C5—H5B107.9C17—C16—C15117.14 (19)
O5—C6—C5123.9 (2)C17—C16—C19121.9 (2)
O5—C6—C1121.56 (19)C15—C16—C19120.9 (2)
C5—C6—C1114.57 (18)C16—C17—C18121.5 (2)
O1—C7—O2123.2 (2)C16—C17—H17A119.3
O1—C7—C3124.5 (2)C18—C17—H17A119.3
O2—C7—C3112.31 (18)C13—C18—C17121.2 (2)
O2—C8—C9105.3 (3)C13—C18—H18A119.4
O2—C8—H8A110.7C17—C18—H18A119.4
C9—C8—H8A110.7C16—C19—H19A109.5
O2—C8—H8B110.7C16—C19—H19B109.5
C9—C8—H8B110.7H19A—C19—H19B109.5
H8A—C8—H8B108.8C16—C19—H19C109.5
C8—C9—H9A109.5H19A—C19—H19C109.5
C8—C9—H9B109.5H19B—C19—H19C109.5
H9A—C9—H9B109.5C4—C20—H20A109.5
C8—C9—H9C109.5C4—C20—H20B109.5
H9A—C9—H9C109.5H20A—C20—H20B109.5
H9B—C9—H9C109.5C4—C20—H20C109.5
O2—C8A—C9A108.8 (6)H20A—C20—H20C109.5
O2—C8A—H8AA109.9H20B—C20—H20C109.5
C9A—C8A—H8AA109.9
C10—C1—C2—C1359.94 (19)C4—C3—C7—O151.1 (3)
C6—C1—C2—C13175.97 (15)C2—C3—C7—O2106.96 (19)
C10—C1—C2—C3174.79 (15)C4—C3—C7—O2129.45 (18)
C6—C1—C2—C350.7 (2)C7—O2—C8—C990.5 (5)
C13—C2—C3—C756.8 (2)C8A—O2—C8—C950.2 (14)
C1—C2—C3—C7179.47 (16)C7—O2—C8A—C9A171.7 (6)
C13—C2—C3—C4179.72 (15)C8—O2—C8A—C9A43.2 (13)
C1—C2—C3—C456.0 (2)C11—O4—C10—O37.4 (3)
C7—C3—C4—O665.3 (2)C11—O4—C10—C1171.67 (18)
C2—C3—C4—O656.0 (2)C6—C1—C10—O377.4 (2)
C7—C3—C4—C2057.6 (2)C2—C1—C10—O347.1 (3)
C2—C3—C4—C20178.94 (17)C6—C1—C10—O4103.56 (19)
C7—C3—C4—C5179.81 (16)C2—C1—C10—O4131.89 (17)
C2—C3—C4—C558.5 (2)C10—O4—C11—C1282.2 (3)
O6—C4—C5—C662.1 (2)C3—C2—C13—C18120.07 (19)
C20—C4—C5—C6179.10 (18)C1—C2—C13—C18116.4 (2)
C3—C4—C5—C656.3 (2)C3—C2—C13—C1460.3 (2)
C4—C5—C6—O5127.0 (2)C1—C2—C13—C1463.3 (2)
C4—C5—C6—C154.1 (2)C18—C13—C14—C150.0 (3)
C10—C1—C6—O56.5 (3)C2—C13—C14—C15179.7 (2)
C2—C1—C6—O5130.1 (2)C13—C14—C15—C160.4 (4)
C10—C1—C6—C5174.63 (17)C14—C15—C16—C170.3 (3)
C2—C1—C6—C551.0 (2)C14—C15—C16—C19179.0 (2)
C8—O2—C7—O10.0 (4)C15—C16—C17—C180.3 (3)
C8A—O2—C7—O112.1 (5)C19—C16—C17—C18178.5 (2)
C8—O2—C7—C3179.5 (3)C14—C13—C18—C170.5 (3)
C8A—O2—C7—C3167.4 (4)C2—C13—C18—C17179.17 (19)
C2—C3—C7—O172.5 (3)C16—C17—C18—C130.7 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O6—H6···O10.91 (4)2.28 (4)2.884 (2)124 (3)
O6—H6···O1i0.91 (4)2.28 (4)3.066 (2)145 (3)
Symmetry code: (i) x+1, y, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O6—H6···O10.91 (4)2.28 (4)2.884 (2)124 (3)
O6—H6···O1i0.91 (4)2.28 (4)3.066 (2)145 (3)
Symmetry code: (i) x+1, y, z.
Acknowledgements top

We thank Baku State University and Vladimir State University for supporting this study.

references
References top

Bruker (2001). SAINT-Plus. Bruker AXS Inc., Madison, Wisconsin, USA.

Bruker (2005). APEX2. Bruker AXS Inc., Madison, Wisconsin, USA.

Gein, V. L., Gein, N. V. & Krivenko, A. P. (2003). Russ. J. Gen. Chem. 73, 490–491.

Gein, V. L., Gein, N. V., Potemkin, K. D. & Krivenko, A. P. (2004). Russ. J. Gen. Chem. 74, 1564–1568.

Sheldrick, G. M. (2003). SADABS. University of Göttingen, Germany.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.

Sorokin, V. V., Grigor'ev, A. V., Ramazanov, A. K. & Krivenko, A. P. (2000). Russ. J. Org. Chem. 36, 781–784.