Buy article online - an online subscription or single-article purchase is required to access this article.
The title compound, bis(2-isopropyl-5-methylcyclohex-1-yl) malonate, C23H40O4, crystallizes in the monoclinic space group P21. In the crystal, the molecule is not C2 symmetric.
Supporting information
CCDC reference: 182024
Malonyl dichloride (5.0 g, 3.45 ml, 35.5 mmol) was slowly added to a stirred
solution of triethylamine (7.1 g, 9.90 ml, 70.9 mmol) and (-)-menthol (11.1 g,
70.9 mmol) in dichloromethane (100 ml), and the resulting solution was stirred
for 1 h. The reaction was quenched slowly with water (30 ml) and the organic
layer was extracted with diethyl ether (3 × 50 ml), dried (MgSO4) and
evaporated under reduced pressure. The residue was purified by flash column
chromatography on silica gel, eluting with light petroleum (313–333 K)-ether
(19:1) to give the title compound, (III) (9.0 g, 66%), as light-cream solid.
This solid was recrystallized using hexane to give colourless needle crystals
(m.p. 327–328 K) Prism given as shape below. Spectroscopic analysis:
Rf [light petroleum (313–333 K):ether (9:1)] 0.75; IR (νmax,
film, cm-1): 1725 (CO); [α]D -83.7 (c. 2.7 in acetone); 1H NMR (250 MHz, CDCl3, δ, p.p.m.): 4.8 (2H, td, J = 10.8 and 4.4 Hz, CHO), 3.36
(2H, s, CH2CO), 2.15–0.85 (18H, m, 6 × CH2 and 6
× CH), 1.1–0.95 (6H, m, 2 × CH3), 0.85 (3H, d, J
= 7.0 Hz, CHCH3); 13C NMR (67 MHz, CDCl3, δ, p.p.m.): 166.2, 75.5,
46.9, 42.4, 40.7, 34.2, 31.4, 26.1, 23.4, 22.0, 20.8, 16.3; analysis found
M+ 381.3017; C23H41O4 requires M+ 381.3005; MS
(m/z): 381 (80%, M), 243 (100, M - C10H18).
H atoms were placed in geometrical positions, with C—H = 0.98–1.0 Å.
Uiso was refined for the H atoms on C2; other H atoms were treated as
riding, with Uiso(H) = 1.2 or 1.5Ueq(C). Are these the
correct restraints?
Data collection: CAD-4-PC Software (Enraf Nonius, 1994); cell refinement: CAD-4-PC Software; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).
Bis(2-isopropyl-5-methylcyclohex-1-yl) malonate
top
Crystal data top
C23H40O4 | F(000) = 420 |
Mr = 380.55 | Dx = 1.112 Mg m−3 |
Monoclinic, P21 | Mo Kα radiation, λ = 0.71069 Å |
a = 12.990 (2) Å | Cell parameters from 25 reflections |
b = 6.092 (3) Å | θ = 8.6–13.4° |
c = 14.528 (2) Å | µ = 0.07 mm−1 |
β = 98.55 (2)° | T = 180 K |
V = 1136.9 (6) Å3 | Prism, colourless |
Z = 2 | 0.2 × 0.2 × 0.2 mm |
Data collection top
Enraf Nonius CAD-4 diffractometer | θmax = 25.0°, θmin = 1.4° |
non–profiled ω/2θ scans | h = −15→15 |
2285 measured reflections | k = 0→7 |
2194 independent reflections | l = 0→17 |
1234 reflections with I > 2σ(I) | 2 standard reflections every 60 min |
Rint = 0.049 | intensity decay: 7% |
Refinement top
Refinement on F2 | 1 restraint |
Least-squares matrix: full | H atoms treated by a mixture of independent and constrained refinement |
R[F2 > 2σ(F2)] = 0.058 | w = 1/[σ2(Fo2) + (0.096P)2] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.163 | (Δ/σ)max = 0.003 |
S = 0.93 | Δρmax = 0.22 e Å−3 |
2194 reflections | Δρmin = −0.21 e Å−3 |
251 parameters | |
Crystal data top
C23H40O4 | V = 1136.9 (6) Å3 |
Mr = 380.55 | Z = 2 |
Monoclinic, P21 | Mo Kα radiation |
a = 12.990 (2) Å | µ = 0.07 mm−1 |
b = 6.092 (3) Å | T = 180 K |
c = 14.528 (2) Å | 0.2 × 0.2 × 0.2 mm |
β = 98.55 (2)° | |
Data collection top
Enraf Nonius CAD-4 diffractometer | Rint = 0.049 |
2285 measured reflections | 2 standard reflections every 60 min |
2194 independent reflections | intensity decay: 7% |
1234 reflections with I > 2σ(I) | |
Refinement top
R[F2 > 2σ(F2)] = 0.058 | 1 restraint |
wR(F2) = 0.163 | H atoms treated by a mixture of independent and constrained refinement |
S = 0.93 | Δρmax = 0.22 e Å−3 |
2194 reflections | Δρmin = −0.21 e Å−3 |
251 parameters | |
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. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
O1 | 0.5999 (3) | 0.6974 (7) | 0.8711 (3) | 0.0421 (10) | |
O2 | 0.3567 (3) | 0.7307 (6) | 0.7709 (2) | 0.0354 (9) | |
O3 | 0.3775 (3) | 0.5342 (8) | 0.9031 (3) | 0.0529 (12) | |
O4 | 0.5993 (3) | 1.0556 (8) | 0.8439 (4) | 0.0710 (15) | |
C1 | 0.5590 (4) | 0.8948 (11) | 0.8681 (4) | 0.0346 (13) | |
C2 | 0.4554 (4) | 0.8918 (11) | 0.9007 (4) | 0.0377 (14) | |
H2A | 0.4175 | 1.0289 | 0.8808 | 0.039 (11)* | |
H2B | 0.4654 | 0.8862 | 0.9695 | 0.039 (11)* | |
C3 | 0.3917 (4) | 0.6988 (11) | 0.8624 (3) | 0.0368 (14) | |
C4 | 0.3127 (4) | 0.5403 (9) | 0.7159 (3) | 0.0301 (13) | |
H4 | 0.2753 | 0.4445 | 0.756 | 0.036* | |
C5 | 0.2351 (4) | 0.6284 (9) | 0.6363 (3) | 0.0304 (13) | |
H5 | 0.2741 | 0.7299 | 0.5998 | 0.036* | |
C6 | 0.1978 (4) | 0.4338 (10) | 0.5718 (4) | 0.0402 (15) | |
H6A | 0.1573 | 0.331 | 0.6052 | 0.048* | |
H6B | 0.1512 | 0.4891 | 0.5165 | 0.048* | |
C7 | 0.2883 (4) | 0.3117 (10) | 0.5403 (4) | 0.0450 (16) | |
H7A | 0.261 | 0.1886 | 0.4993 | 0.054* | |
H7B | 0.3262 | 0.4123 | 0.5036 | 0.054* | |
C8 | 0.3631 (4) | 0.2228 (10) | 0.6213 (4) | 0.0401 (14) | |
H8 | 0.3244 | 0.1175 | 0.6565 | 0.048* | |
C9 | 0.4011 (4) | 0.4129 (10) | 0.6858 (4) | 0.0380 (14) | |
H9A | 0.4459 | 0.3547 | 0.7416 | 0.046* | |
H9B | 0.4439 | 0.5128 | 0.6533 | 0.046* | |
C10 | 0.4551 (5) | 0.1026 (11) | 0.5911 (4) | 0.0551 (18) | |
H10A | 0.4919 | 0.2013 | 0.5538 | 0.083* | |
H10B | 0.43 | −0.0258 | 0.5537 | 0.083* | |
H10C | 0.5026 | 0.055 | 0.6462 | 0.083* | |
C11 | 0.1464 (4) | 0.7608 (10) | 0.6667 (3) | 0.0359 (14) | |
H11 | 0.1787 | 0.8811 | 0.7081 | 0.043* | |
C12 | 0.0766 (4) | 0.6287 (12) | 0.7227 (4) | 0.0558 (19) | |
H12A | 0.1194 | 0.5615 | 0.7766 | 0.084* | |
H12B | 0.0406 | 0.5135 | 0.6832 | 0.084* | |
H12C | 0.0252 | 0.7266 | 0.7441 | 0.084* | |
C13 | 0.0783 (5) | 0.8700 (11) | 0.5842 (4) | 0.0477 (16) | |
H13A | 0.0393 | 0.7572 | 0.5455 | 0.072* | |
H13B | 0.1225 | 0.9512 | 0.547 | 0.072* | |
H13C | 0.0295 | 0.9715 | 0.6074 | 0.072* | |
C14 | 0.7019 (4) | 0.6626 (10) | 0.8422 (4) | 0.0334 (14) | |
H14 | 0.7333 | 0.8065 | 0.8284 | 0.04* | |
C15 | 0.6828 (4) | 0.5236 (10) | 0.7551 (4) | 0.0381 (14) | |
H15A | 0.6415 | 0.609 | 0.7046 | 0.046* | |
H15B | 0.6416 | 0.3927 | 0.7672 | 0.046* | |
C16 | 0.7843 (4) | 0.4500 (10) | 0.7238 (4) | 0.0398 (15) | |
H16 | 0.8214 | 0.582 | 0.7044 | 0.048* | |
C17 | 0.8530 (5) | 0.3378 (10) | 0.8030 (4) | 0.0425 (16) | |
H17A | 0.9207 | 0.3015 | 0.7832 | 0.051* | |
H17B | 0.8198 | 0.1988 | 0.8182 | 0.051* | |
C18 | 0.8713 (4) | 0.4814 (11) | 0.8888 (4) | 0.0426 (16) | |
H18A | 0.9095 | 0.615 | 0.8748 | 0.051* | |
H18B | 0.9153 | 0.4011 | 0.9393 | 0.051* | |
C19 | 0.7701 (4) | 0.5483 (9) | 0.9221 (3) | 0.0293 (12) | |
H19 | 0.7335 | 0.4102 | 0.9355 | 0.035* | |
C20 | 0.7855 (4) | 0.6864 (10) | 1.0129 (3) | 0.0411 (15) | |
H20 | 0.7145 | 0.7185 | 1.0285 | 0.049* | |
C21 | 0.8435 (5) | 0.5582 (12) | 1.0943 (4) | 0.0583 (18) | |
H21A | 0.8431 | 0.6415 | 1.1519 | 0.087* | |
H21B | 0.9155 | 0.5342 | 1.084 | 0.087* | |
H21C | 0.8093 | 0.4162 | 1.0993 | 0.087* | |
C22 | 0.8379 (5) | 0.9049 (12) | 1.0031 (4) | 0.0492 (16) | |
H22A | 0.9057 | 0.8807 | 0.983 | 0.074* | |
H22B | 0.8476 | 0.9812 | 1.0631 | 0.074* | |
H22C | 0.7942 | 0.9945 | 0.9567 | 0.074* | |
C23 | 0.7612 (5) | 0.2933 (12) | 0.6404 (4) | 0.061 (2) | |
H23A | 0.7249 | 0.1631 | 0.6588 | 0.091* | |
H23B | 0.8267 | 0.249 | 0.62 | 0.091* | |
H23C | 0.7172 | 0.3681 | 0.5892 | 0.091* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
O1 | 0.037 (2) | 0.034 (3) | 0.058 (2) | 0.001 (2) | 0.0139 (18) | 0.002 (2) |
O2 | 0.042 (2) | 0.035 (2) | 0.0265 (18) | −0.0040 (19) | −0.0027 (15) | 0.0043 (18) |
O3 | 0.057 (3) | 0.062 (3) | 0.038 (2) | −0.012 (2) | 0.0010 (19) | 0.019 (2) |
O4 | 0.057 (3) | 0.048 (3) | 0.110 (4) | 0.005 (3) | 0.019 (3) | 0.026 (3) |
C1 | 0.039 (3) | 0.026 (4) | 0.035 (3) | −0.001 (3) | −0.007 (2) | 0.003 (3) |
C2 | 0.039 (3) | 0.042 (4) | 0.029 (3) | 0.001 (3) | −0.003 (2) | −0.017 (3) |
C3 | 0.035 (3) | 0.053 (4) | 0.022 (3) | 0.009 (3) | 0.002 (2) | 0.002 (3) |
C4 | 0.039 (3) | 0.021 (3) | 0.028 (3) | −0.009 (3) | −0.001 (2) | 0.005 (3) |
C5 | 0.038 (3) | 0.026 (3) | 0.026 (3) | −0.006 (3) | 0.002 (2) | 0.009 (2) |
C6 | 0.050 (4) | 0.036 (4) | 0.033 (3) | −0.016 (3) | 0.000 (3) | −0.005 (3) |
C7 | 0.056 (4) | 0.036 (4) | 0.044 (4) | −0.008 (3) | 0.008 (3) | −0.012 (3) |
C8 | 0.047 (3) | 0.023 (3) | 0.053 (3) | −0.006 (3) | 0.014 (3) | −0.001 (3) |
C9 | 0.042 (3) | 0.034 (4) | 0.038 (3) | −0.008 (3) | 0.006 (3) | 0.005 (3) |
C10 | 0.064 (4) | 0.042 (4) | 0.060 (4) | 0.001 (4) | 0.011 (3) | −0.008 (3) |
C11 | 0.026 (3) | 0.045 (4) | 0.036 (3) | −0.006 (3) | 0.000 (2) | 0.000 (3) |
C12 | 0.050 (4) | 0.069 (5) | 0.054 (4) | 0.001 (4) | 0.023 (3) | 0.007 (4) |
C13 | 0.049 (3) | 0.043 (4) | 0.048 (4) | 0.012 (3) | −0.001 (3) | 0.007 (3) |
C14 | 0.022 (3) | 0.034 (4) | 0.046 (3) | −0.005 (2) | 0.011 (2) | 0.003 (3) |
C15 | 0.040 (3) | 0.032 (4) | 0.041 (3) | −0.010 (3) | 0.001 (2) | 0.008 (3) |
C16 | 0.055 (4) | 0.033 (4) | 0.034 (3) | −0.013 (3) | 0.015 (3) | 0.005 (3) |
C17 | 0.057 (4) | 0.033 (4) | 0.040 (3) | 0.004 (3) | 0.018 (3) | −0.001 (3) |
C18 | 0.039 (3) | 0.054 (4) | 0.036 (3) | 0.005 (3) | 0.010 (3) | 0.000 (3) |
C19 | 0.033 (3) | 0.025 (3) | 0.031 (3) | −0.001 (3) | 0.010 (2) | −0.004 (3) |
C20 | 0.052 (3) | 0.040 (4) | 0.034 (3) | 0.000 (3) | 0.015 (3) | −0.002 (3) |
C21 | 0.091 (5) | 0.048 (4) | 0.036 (3) | 0.000 (4) | 0.010 (3) | −0.002 (3) |
C22 | 0.057 (4) | 0.050 (4) | 0.039 (3) | −0.016 (4) | 0.002 (3) | −0.001 (3) |
C23 | 0.076 (5) | 0.077 (6) | 0.031 (3) | 0.001 (4) | 0.014 (3) | −0.013 (3) |
Geometric parameters (Å, º) top
O1—C1 | 1.313 (7) | C12—H12B | 0.98 |
O1—C14 | 1.463 (6) | C12—H12C | 0.98 |
O2—C3 | 1.353 (6) | C13—H13A | 0.98 |
O2—C4 | 1.475 (6) | C13—H13B | 0.98 |
O3—C3 | 1.192 (7) | C13—H13C | 0.98 |
O4—C1 | 1.188 (7) | C14—C15 | 1.511 (7) |
C1—C2 | 1.492 (7) | C14—C19 | 1.521 (7) |
C2—C3 | 1.497 (8) | C14—H14 | 1.0 |
C2—H2A | 0.99 | C15—C16 | 1.525 (8) |
C2—H2B | 0.99 | C15—H15A | 0.99 |
C4—C9 | 1.504 (7) | C15—H15B | 0.99 |
C4—C5 | 1.515 (6) | C16—C17 | 1.510 (7) |
C4—H4 | 1.0 | C16—C23 | 1.537 (8) |
C5—C11 | 1.525 (7) | C16—H16 | 1.0 |
C5—C6 | 1.544 (7) | C17—C18 | 1.513 (8) |
C5—H5 | 1.0 | C17—H17A | 0.99 |
C6—C7 | 1.519 (8) | C17—H17B | 0.99 |
C6—H6A | 0.99 | C18—C19 | 1.522 (7) |
C6—H6B | 0.99 | C18—H18A | 0.99 |
C7—C8 | 1.511 (8) | C18—H18B | 0.99 |
C7—H7A | 0.99 | C19—C20 | 1.553 (7) |
C7—H7B | 0.99 | C19—H19 | 1.0 |
C8—C10 | 1.521 (8) | C20—C22 | 1.512 (8) |
C8—C9 | 1.525 (8) | C20—C21 | 1.520 (8) |
C8—H8 | 1.0 | C20—H20 | 1.0 |
C9—H9A | 0.99 | C21—H21A | 0.98 |
C9—H9B | 0.99 | C21—H21B | 0.98 |
C10—H10A | 0.98 | C21—H21C | 0.98 |
C10—H10B | 0.98 | C22—H22A | 0.98 |
C10—H10C | 0.98 | C22—H22B | 0.98 |
C11—C13 | 1.532 (7) | C22—H22C | 0.98 |
C11—C12 | 1.533 (7) | C23—H23A | 0.98 |
C11—H11 | 1.0 | C23—H23B | 0.98 |
C12—H12A | 0.98 | C23—H23C | 0.98 |
| | | |
C1—O1—C14 | 120.1 (4) | H12B—C12—H12C | 109.5 |
C3—O2—C4 | 117.7 (4) | C11—C13—H13A | 109.5 |
O4—C1—O1 | 124.8 (5) | C11—C13—H13B | 109.5 |
O4—C1—C2 | 124.2 (6) | H13A—C13—H13B | 109.5 |
O1—C1—C2 | 111.0 (5) | C11—C13—H13C | 109.5 |
C1—C2—C3 | 111.5 (5) | H13A—C13—H13C | 109.5 |
C1—C2—H2A | 109.3 | H13B—C13—H13C | 109.5 |
C3—C2—H2A | 109.3 | O1—C14—C15 | 106.2 (4) |
C1—C2—H2B | 109.3 | O1—C14—C19 | 107.3 (4) |
C3—C2—H2B | 109.3 | C15—C14—C19 | 112.7 (5) |
H2A—C2—H2B | 108 | O1—C14—H14 | 110.2 |
O3—C3—O2 | 123.7 (6) | C15—C14—H14 | 110.2 |
O3—C3—C2 | 126.4 (5) | C19—C14—H14 | 110.2 |
O2—C3—C2 | 109.8 (5) | C14—C15—C16 | 111.9 (4) |
O2—C4—C9 | 108.2 (4) | C14—C15—H15A | 109.2 |
O2—C4—C5 | 107.2 (4) | C16—C15—H15A | 109.2 |
C9—C4—C5 | 114.3 (4) | C14—C15—H15B | 109.2 |
O2—C4—H4 | 109 | C16—C15—H15B | 109.2 |
C9—C4—H4 | 109 | H15A—C15—H15B | 107.9 |
C5—C4—H4 | 109 | C17—C16—C15 | 110.2 (4) |
C4—C5—C11 | 114.3 (4) | C17—C16—C23 | 110.1 (5) |
C4—C5—C6 | 107.7 (4) | C15—C16—C23 | 110.0 (5) |
C11—C5—C6 | 113.5 (4) | C17—C16—H16 | 108.9 |
C4—C5—H5 | 106.9 | C15—C16—H16 | 108.9 |
C11—C5—H5 | 106.9 | C23—C16—H16 | 108.9 |
C6—C5—H5 | 106.9 | C16—C17—C18 | 111.6 (5) |
C7—C6—C5 | 111.8 (4) | C16—C17—H17A | 109.3 |
C7—C6—H6A | 109.3 | C18—C17—H17A | 109.3 |
C5—C6—H6A | 109.3 | C16—C17—H17B | 109.3 |
C7—C6—H6B | 109.3 | C18—C17—H17B | 109.3 |
C5—C6—H6B | 109.3 | H17A—C17—H17B | 108 |
H6A—C6—H6B | 107.9 | C17—C18—C19 | 112.3 (5) |
C8—C7—C6 | 112.2 (5) | C17—C18—H18A | 109.1 |
C8—C7—H7A | 109.2 | C19—C18—H18A | 109.1 |
C6—C7—H7A | 109.2 | C17—C18—H18B | 109.1 |
C8—C7—H7B | 109.2 | C19—C18—H18B | 109.1 |
C6—C7—H7B | 109.2 | H18A—C18—H18B | 107.9 |
H7A—C7—H7B | 107.9 | C14—C19—C18 | 108.3 (4) |
C7—C8—C10 | 112.9 (5) | C14—C19—C20 | 112.8 (4) |
C7—C8—C9 | 108.6 (5) | C18—C19—C20 | 114.0 (4) |
C10—C8—C9 | 110.2 (5) | C14—C19—H19 | 107.1 |
C7—C8—H8 | 108.3 | C18—C19—H19 | 107.1 |
C10—C8—H8 | 108.3 | C20—C19—H19 | 107.1 |
C9—C8—H8 | 108.3 | C22—C20—C21 | 110.4 (5) |
C4—C9—C8 | 112.3 (4) | C22—C20—C19 | 113.5 (4) |
C4—C9—H9A | 109.2 | C21—C20—C19 | 111.6 (5) |
C8—C9—H9A | 109.2 | C22—C20—H20 | 107 |
C4—C9—H9B | 109.2 | C21—C20—H20 | 107 |
C8—C9—H9B | 109.2 | C19—C20—H20 | 107 |
H9A—C9—H9B | 107.9 | C20—C21—H21A | 109.5 |
C8—C10—H10A | 109.5 | C20—C21—H21B | 109.5 |
C8—C10—H10B | 109.5 | H21A—C21—H21B | 109.5 |
H10A—C10—H10B | 109.5 | C20—C21—H21C | 109.5 |
C8—C10—H10C | 109.5 | H21A—C21—H21C | 109.5 |
H10A—C10—H10C | 109.5 | H21B—C21—H21C | 109.5 |
H10B—C10—H10C | 109.5 | C20—C22—H22A | 109.5 |
C5—C11—C13 | 112.1 (4) | C20—C22—H22B | 109.5 |
C5—C11—C12 | 114.1 (5) | H22A—C22—H22B | 109.5 |
C13—C11—C12 | 108.9 (4) | C20—C22—H22C | 109.5 |
C5—C11—H11 | 107.1 | H22A—C22—H22C | 109.5 |
C13—C11—H11 | 107.1 | H22B—C22—H22C | 109.5 |
C12—C11—H11 | 107.1 | C16—C23—H23A | 109.5 |
C11—C12—H12A | 109.5 | C16—C23—H23B | 109.5 |
C11—C12—H12B | 109.5 | H23A—C23—H23B | 109.5 |
H12A—C12—H12B | 109.5 | C16—C23—H23C | 109.5 |
C11—C12—H12C | 109.5 | H23A—C23—H23C | 109.5 |
H12A—C12—H12C | 109.5 | H23B—C23—H23C | 109.5 |
| | | |
C14—O1—C1—O4 | −0.8 (8) | C4—C5—C11—C13 | 172.8 (5) |
C14—O1—C1—C2 | −180.0 (4) | C6—C5—C11—C13 | −63.1 (6) |
O4—C1—C2—C3 | 138.3 (6) | C4—C5—C11—C12 | −62.8 (6) |
O1—C1—C2—C3 | −42.5 (6) | C6—C5—C11—C12 | 61.3 (6) |
C4—O2—C3—O3 | −9.5 (7) | C1—O1—C14—C15 | −113.5 (5) |
C4—O2—C3—C2 | 166.6 (4) | C1—O1—C14—C19 | 125.7 (5) |
C1—C2—C3—O3 | 102.6 (6) | O1—C14—C15—C16 | −172.8 (4) |
C1—C2—C3—O2 | −73.4 (6) | C19—C14—C15—C16 | −55.7 (6) |
C3—O2—C4—C9 | −83.6 (5) | C14—C15—C16—C17 | 53.6 (6) |
C3—O2—C4—C5 | 152.7 (4) | C14—C15—C16—C23 | 175.1 (5) |
O2—C4—C5—C11 | −59.2 (5) | C15—C16—C17—C18 | −54.5 (6) |
C9—C4—C5—C11 | −179.1 (4) | C23—C16—C17—C18 | −176.0 (5) |
O2—C4—C5—C6 | 173.6 (4) | C16—C17—C18—C19 | 57.7 (6) |
C9—C4—C5—C6 | 53.8 (6) | O1—C14—C19—C18 | 172.1 (4) |
C4—C5—C6—C7 | −54.5 (6) | C15—C14—C19—C18 | 55.6 (6) |
C11—C5—C6—C7 | 177.9 (4) | O1—C14—C19—C20 | −60.7 (5) |
C5—C6—C7—C8 | 58.8 (6) | C15—C14—C19—C20 | −177.2 (4) |
C6—C7—C8—C10 | −179.2 (5) | C17—C18—C19—C14 | −56.4 (6) |
C6—C7—C8—C9 | −56.7 (6) | C17—C18—C19—C20 | 177.1 (5) |
O2—C4—C9—C8 | −175.1 (4) | C14—C19—C20—C22 | −60.9 (6) |
C5—C4—C9—C8 | −55.8 (6) | C18—C19—C20—C22 | 63.1 (6) |
C7—C8—C9—C4 | 54.5 (6) | C14—C19—C20—C21 | 173.6 (4) |
C10—C8—C9—C4 | 178.7 (5) | C18—C19—C20—C21 | −62.4 (6) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
C15—H15B···O4i | 0.99 | 2.44 | 3.374 (8) | 157 |
C20—H20···O3ii | 1.00 | 2.54 | 3.351 (7) | 138 |
Symmetry codes: (i) x, y−1, z; (ii) −x+1, y+1/2, −z+2. |
Experimental details
Crystal data |
Chemical formula | C23H40O4 |
Mr | 380.55 |
Crystal system, space group | Monoclinic, P21 |
Temperature (K) | 180 |
a, b, c (Å) | 12.990 (2), 6.092 (3), 14.528 (2) |
β (°) | 98.55 (2) |
V (Å3) | 1136.9 (6) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.07 |
Crystal size (mm) | 0.2 × 0.2 × 0.2 |
|
Data collection |
Diffractometer | Enraf Nonius CAD-4 diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2285, 2194, 1234 |
Rint | 0.049 |
(sin θ/λ)max (Å−1) | 0.594 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.058, 0.163, 0.93 |
No. of reflections | 2194 |
No. of parameters | 251 |
No. of restraints | 1 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.22, −0.21 |
Selected geometric parameters (Å, º) topC1—C2 | 1.492 (7) | C2—C3 | 1.497 (8) |
| | | |
C14—O1—C1—O4 | −0.8 (8) | C4—O2—C3—O3 | −9.5 (7) |
C14—O1—C1—C2 | −180.0 (4) | C4—O2—C3—C2 | 166.6 (4) |
O4—C1—C2—C3 | 138.3 (6) | C1—C2—C3—O3 | 102.6 (6) |
O1—C1—C2—C3 | −42.5 (6) | C1—C2—C3—O2 | −73.4 (6) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
C15—H15B···O4i | 0.99 | 2.44 | 3.374 (8) | 157 |
C20—H20···O3ii | 1.00 | 2.54 | 3.351 (7) | 138 |
Symmetry codes: (i) x, y−1, z; (ii) −x+1, y+1/2, −z+2. |
Subscribe to Acta Crystallographica Section C: Structural Chemistry
The full text of this article is available to subscribers to the journal.
If you have already registered and are using a computer listed in your registration details, please email
support@iucr.org for assistance.
A large number of substituted malonic acid derivatives are known (Kanters & Kroon, 1972). Some attention has been focused on related keto (Adhikesavalu & Venkatesan, 1983) and aldehyde derivatives (Lundgren & Aurivillius, 1964), but little attention has been paid to the corresponding malonate ester derivatives. We were originally interested in the conformational preference of simple 1,3-dicarbonyl-containing molecules. To this aim, we synthesized the title C2-symmetric dimenthyl malonate, (III), as our model compound. We chose the enantiopure (-)-menthol, (I), as our ester scaffold, as this would lead directly to enantiopure C2-symmetric (III) without contamination resulting from the formation of other stereoisomers. Addition of commercially available malonyl dichloride, (II), to a stirred solution of natural (-)-menthol and triethylamine in dichloromethane gave the required (-)-dimenthyl malonate, (III), as a cream-coloured precipitate in good yield (66%). The crude product was purified by flash column chromatography on silica gel, eluting with light petroleum (313–333 K)-ether (19:1) mixture, and was then vapour recrystallized from hexane to give colourless needle-like crystals of (III). \sch
X-ray diffraction of (III) revealed its structure, illustrated in Fig. 1. The stereochemistry was assigned by reference to (-)-menthol. It was immediately evident that this molecule was not C2 symmetric in its solid phase, due to the non-equivalence of the carbonyl groups C1═O4 and C3═O3. By comparison, solution phase NMR studies at room temperature are consistent with C2 symmetry. We ascribe the conformation of this molecule in the crystal state to packing effects. The overall unit cell is pseudo C2 symmetric and contains two identical malonate molecules, as shown in Fig. 2.
The molecule is certainly not an enol derivative, with a C1—C2—C3 bond angle of 111.5 (5)° and not significantly different C1—C2 and C2—C3 bond lengths of 1.492 (7) and 1.497 (8) Å, respectively (Table 1). All the substituents on the cyclohexyl ring are in the expected equatorial position.
The most striking structural feature is the relative conformation of both carbonyl groups, C1═O4 and C3═O3. They are clearly twisted away from each other, as shown by the torsion angles of 138.3 (6)° for O4—C1—C2—O3 and 102.6 (6)° for C1—C2—C3—O3. This is presumably due to a combination of hyperconjugation effects at C2—H with both carbonyl groups and a minimization of their relative dipole moments. This can also be seen in a related twist involving the other O atom in the ester motif, as shown by the torsion angles of -42.5 (6)° for O1—C1—C2—C3 and -73.4 (6)° for C1—C2—C3—O2. In contrast, both the ester groups strive for planarity [-9.5 (7)° for C4—O2—C3—O3 and -0.8 (8)° for C14—O1—C1—O4] through anomeric assistance (Table 1).
This type of anti-parallel alignment has been reported in the structural arrangement of diimidazolines (Brennan & McKee, 1999), diones (Klein et al., 1999) and related malonic acid derivatives (Kalsbeek, 1992). The effect of the non-equivalence of the menthyl groups is more interesting and can be seen more clearly by the non-equivalence of the ester groups. The torsion angle of the ester group C14—O1—C1—C2 is planar [-180.0 (4)°], whereas the related ester grouping C4—O2—C3—C2 certainly has a slight twist [166.6 (4)°] (Table 1). This is more than likely due to a combination of crystal-packing effects and the presence of a local pseudo twofold axis (Table 2 and Fig. 2). This layer sequence is positioned in an ABAB system, with layer B oriented anti-parallel to layer A.