The structure of the title compound, C14H18O5, has two independent molecules related by a local noncrystallographic a-glide plane perpendicular to the b axis. The pseudo-glide plane shows a discontinuity at z = 0. Both molecules have an intramolecular hydrogen bond between the hydroxy and aldehyde groups. There are stacks of molecules along the a-axis direction. Neighboring molecules in the stack have an interplanar angle of 1.6 (1)°, interplanar distances ranging between 3.399 (3) and 3.417 (3) Å, and a ring offset of 1.38 (1) Å.
Supporting information
CCDC reference: 669195
The preparation of (I) has been reported by Köck et al. (1996). Single crystals were obtained by slow evaporation of a solution of (I) in CDCl3 at about 280 K.
H atoms were positioned geometrically and tretaed as riding [Csp2—H = 0.95 Å, Cprimary—H = 1.00 Å, Csecondary—H = 0.99 Å, Cmethyl—H = 0.98 Å, O—H = 0.84 Å, and Uiso(H) = 1.2Ueq(C) and 1.5Ueq(Cmethyl,O)]. The torsion angle about the C—C axis was refined for the methyl groups and the torsion angle about the C—O axis was refined for the hydroxy groups. The triclinic unit cell can be transformed to a C-centered cell with monoclinic shape. The Laue symmetry, however, showed the structure to be triclinic (Rint = 0.067) rather than monoclinic (Rint = 0.56). The present unit cell can be reduced by the transformation ared = −a, bred = b and cred = −a − c. The choice of the reduced cell was found to depend on the exact value of the cell angle β and changed during the final refinement of the unit-cell parameters. The original setting was retained in this work.
Data collection: SMART (Siemens, 1995); cell refinement: SMART (Siemens, 1995); data reduction: SAINT (Siemens, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Sheldrick, 1996); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997).
2-Hydroxy-4,6-dimethoxy-3-(3-methylbutanoyl)benzaldehyde
top
Crystal data top
C14H18O5 | Z = 4 |
Mr = 266.28 | F(000) = 568 |
Triclinic, P1 | Dx = 1.333 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 7.2946 (10) Å | Cell parameters from 164 reflections |
b = 8.2775 (13) Å | θ = 3–23° |
c = 22.400 (3) Å | µ = 0.10 mm−1 |
α = 95.949 (6)° | T = 160 K |
β = 99.410 (8)° | Rod, colorless |
γ = 90.099 (6)° | 0.50 × 0.22 × 0.16 mm |
V = 1326.9 (3) Å3 | |
Data collection top
Siemens SMART 1K CCD diffractometer | 3128 reflections with I > 2σ(I) |
Radiation source: normal-focus sealed tube | Rint = 0.067 |
Graphite monochromator | θmax = 27.5°, θmin = 1.9° |
ω scans | h = −9→9 |
19412 measured reflections | k = −10→10 |
5830 independent reflections | l = −28→28 |
Refinement top
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.051 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.131 | H-atom parameters constrained |
S = 0.97 | w = 1/[σ2(Fo2) + (0.06P)2] where P = (Fo2 + 2Fc2)/3 |
5830 reflections | (Δ/σ)max = 0.001 |
353 parameters | Δρmax = 0.23 e Å−3 |
0 restraints | Δρmin = −0.24 e Å−3 |
Crystal data top
C14H18O5 | γ = 90.099 (6)° |
Mr = 266.28 | V = 1326.9 (3) Å3 |
Triclinic, P1 | Z = 4 |
a = 7.2946 (10) Å | Mo Kα radiation |
b = 8.2775 (13) Å | µ = 0.10 mm−1 |
c = 22.400 (3) Å | T = 160 K |
α = 95.949 (6)° | 0.50 × 0.22 × 0.16 mm |
β = 99.410 (8)° | |
Data collection top
Siemens SMART 1K CCD diffractometer | 3128 reflections with I > 2σ(I) |
19412 measured reflections | Rint = 0.067 |
5830 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.051 | 0 restraints |
wR(F2) = 0.131 | H-atom parameters constrained |
S = 0.97 | Δρmax = 0.23 e Å−3 |
5830 reflections | Δρmin = −0.24 e Å−3 |
353 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. |
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 | x | y | z | Uiso*/Ueq | |
O1 | 0.4421 (2) | 0.99181 (17) | 0.27024 (7) | 0.0303 (4) | |
O2 | 0.5985 (2) | 0.97494 (16) | 0.16837 (6) | 0.0286 (4) | |
H2 | 0.6286 | 0.9947 | 0.1352 | 0.043* | |
O3 | 0.6770 (2) | 0.92291 (18) | 0.06135 (7) | 0.0339 (4) | |
O4 | 0.6531 (2) | 0.44873 (16) | 0.07131 (6) | 0.0294 (4) | |
O5 | 0.5163 (2) | 0.52705 (17) | 0.27523 (6) | 0.0280 (4) | |
C1 | 0.5566 (3) | 0.7526 (2) | 0.22359 (9) | 0.0215 (5) | |
C2 | 0.5903 (3) | 0.8130 (2) | 0.17034 (9) | 0.0220 (5) | |
C3 | 0.6223 (3) | 0.7097 (2) | 0.11897 (9) | 0.0219 (5) | |
C4 | 0.6179 (3) | 0.5405 (2) | 0.12210 (9) | 0.0233 (5) | |
C5 | 0.5806 (3) | 0.4767 (2) | 0.17310 (9) | 0.0229 (5) | |
H5 | 0.5741 | 0.3624 | 0.1741 | 0.028* | |
C6 | 0.5522 (3) | 0.5824 (2) | 0.22355 (9) | 0.0229 (5) | |
C7 | 0.5322 (3) | 0.8695 (3) | 0.27780 (9) | 0.0232 (5) | |
C8 | 0.6337 (3) | 0.8413 (2) | 0.34006 (9) | 0.0280 (5) | |
H8A | 0.7627 | 0.8098 | 0.3365 | 0.034* | |
H8B | 0.5727 | 0.7491 | 0.3544 | 0.034* | |
C9 | 0.6400 (3) | 0.9884 (3) | 0.38773 (10) | 0.0348 (6) | |
H9 | 0.6683 | 1.0873 | 0.3685 | 0.042* | |
C10 | 0.4555 (4) | 1.0129 (3) | 0.41024 (11) | 0.0520 (8) | |
H10A | 0.4273 | 0.9189 | 0.4306 | 0.078* | |
H10B | 0.3570 | 1.0244 | 0.3756 | 0.078* | |
H10C | 0.4633 | 1.1113 | 0.4390 | 0.078* | |
C11 | 0.7954 (4) | 0.9700 (3) | 0.44102 (11) | 0.0518 (8) | |
H11A | 0.8010 | 1.0661 | 0.4708 | 0.078* | |
H11B | 0.9143 | 0.9588 | 0.4261 | 0.078* | |
H11C | 0.7708 | 0.8731 | 0.4604 | 0.078* | |
C12 | 0.6669 (3) | 0.7753 (3) | 0.06646 (10) | 0.0278 (5) | |
H12 | 0.6903 | 0.7013 | 0.0333 | 0.033* | |
C13 | 0.6574 (3) | 0.2756 (2) | 0.07226 (10) | 0.0306 (6) | |
H13A | 0.7485 | 0.2486 | 0.1069 | 0.046* | |
H13B | 0.6925 | 0.2250 | 0.0343 | 0.046* | |
H13C | 0.5341 | 0.2351 | 0.0762 | 0.046* | |
C14 | 0.5009 (3) | 0.3543 (2) | 0.27716 (10) | 0.0312 (6) | |
H14A | 0.4012 | 0.3091 | 0.2450 | 0.047* | |
H14B | 0.4723 | 0.3324 | 0.3168 | 0.047* | |
H14C | 0.6187 | 0.3037 | 0.2710 | 0.047* | |
O6 | −0.0592 (2) | 0.41049 (17) | 0.26941 (6) | 0.0299 (4) | |
O7 | 0.0955 (2) | 0.37158 (16) | 0.16711 (6) | 0.0292 (4) | |
H7 | 0.1224 | 0.3340 | 0.1334 | 0.044* | |
O8 | 0.1716 (2) | 0.36713 (18) | 0.05945 (7) | 0.0349 (4) | |
O9 | 0.1570 (2) | 0.84623 (16) | 0.07265 (6) | 0.0291 (4) | |
O10 | 0.0167 (2) | 0.87816 (16) | 0.27580 (6) | 0.0285 (4) | |
C15 | 0.0568 (3) | 0.6244 (2) | 0.22362 (9) | 0.0219 (5) | |
C16 | 0.0888 (3) | 0.5355 (2) | 0.16986 (9) | 0.0227 (5) | |
C17 | 0.1224 (3) | 0.6109 (2) | 0.11911 (9) | 0.0228 (5) | |
C18 | 0.1197 (3) | 0.7824 (2) | 0.12264 (9) | 0.0245 (5) | |
C19 | 0.0820 (3) | 0.8738 (2) | 0.17419 (9) | 0.0239 (5) | |
H19 | 0.0760 | 0.9887 | 0.1757 | 0.029* | |
C20 | 0.0528 (3) | 0.7950 (2) | 0.22393 (9) | 0.0224 (5) | |
C21 | 0.0327 (3) | 0.5366 (3) | 0.27717 (10) | 0.0249 (5) | |
C22 | 0.1337 (3) | 0.5978 (3) | 0.33969 (9) | 0.0279 (5) | |
H22A | 0.0732 | 0.6979 | 0.3543 | 0.033* | |
H22B | 0.2629 | 0.6275 | 0.3364 | 0.033* | |
C23 | 0.1395 (3) | 0.4778 (3) | 0.38708 (10) | 0.0340 (6) | |
H23 | 0.1667 | 0.3682 | 0.3676 | 0.041* | |
C24 | −0.0463 (4) | 0.4659 (3) | 0.40937 (12) | 0.0535 (7) | |
H24A | −0.0732 | 0.5708 | 0.4304 | 0.080* | |
H24B | −0.0401 | 0.3821 | 0.4375 | 0.080* | |
H24C | −0.1449 | 0.4371 | 0.3745 | 0.080* | |
C25 | 0.2947 (4) | 0.5237 (3) | 0.44056 (11) | 0.0510 (7) | |
H25A | 0.4144 | 0.5229 | 0.4260 | 0.076* | |
H25B | 0.2963 | 0.4451 | 0.4705 | 0.076* | |
H25C | 0.2734 | 0.6325 | 0.4596 | 0.076* | |
C26 | 0.1641 (3) | 0.5172 (3) | 0.06555 (10) | 0.0280 (5) | |
H26 | 0.1874 | 0.5740 | 0.0327 | 0.034* | |
C27 | 0.1609 (3) | 1.0195 (2) | 0.07336 (10) | 0.0301 (5) | |
H27A | 0.0369 | 1.0615 | 0.0763 | 0.045* | |
H27B | 0.1988 | 1.0486 | 0.0358 | 0.045* | |
H27C | 0.2498 | 1.0668 | 0.1085 | 0.045* | |
C28 | 0.0027 (3) | 1.0527 (2) | 0.27838 (10) | 0.0311 (6) | |
H28A | 0.1202 | 1.0995 | 0.2717 | 0.047* | |
H28B | −0.0235 | 1.0961 | 0.3184 | 0.047* | |
H28C | −0.0981 | 1.0807 | 0.2468 | 0.047* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
O1 | 0.0326 (9) | 0.0250 (9) | 0.0319 (9) | 0.0064 (7) | 0.0037 (7) | −0.0005 (7) |
O2 | 0.0392 (10) | 0.0197 (9) | 0.0281 (9) | −0.0013 (7) | 0.0082 (8) | 0.0037 (6) |
O3 | 0.0480 (11) | 0.0242 (9) | 0.0316 (9) | 0.0013 (7) | 0.0113 (8) | 0.0058 (7) |
O4 | 0.0426 (10) | 0.0214 (9) | 0.0248 (8) | 0.0007 (7) | 0.0099 (7) | −0.0015 (6) |
O5 | 0.0352 (9) | 0.0233 (9) | 0.0273 (9) | −0.0003 (7) | 0.0088 (7) | 0.0047 (6) |
C1 | 0.0190 (11) | 0.0206 (12) | 0.0238 (12) | 0.0011 (9) | 0.0016 (9) | 0.0000 (9) |
C2 | 0.0207 (11) | 0.0173 (12) | 0.0270 (12) | 0.0009 (9) | 0.0005 (9) | 0.0030 (9) |
C3 | 0.0223 (11) | 0.0202 (12) | 0.0220 (11) | 0.0003 (9) | 0.0014 (9) | 0.0010 (9) |
C4 | 0.0204 (11) | 0.0231 (12) | 0.0250 (12) | −0.0009 (9) | 0.0023 (9) | −0.0017 (9) |
C5 | 0.0227 (12) | 0.0175 (12) | 0.0279 (13) | 0.0000 (9) | 0.0028 (10) | 0.0016 (9) |
C6 | 0.0191 (11) | 0.0244 (13) | 0.0250 (12) | −0.0001 (9) | 0.0020 (9) | 0.0042 (9) |
C7 | 0.0214 (12) | 0.0235 (12) | 0.0246 (12) | −0.0045 (9) | 0.0052 (9) | 0.0001 (9) |
C8 | 0.0263 (12) | 0.0314 (13) | 0.0260 (12) | 0.0016 (10) | 0.0043 (10) | 0.0011 (10) |
C9 | 0.0391 (14) | 0.0365 (14) | 0.0261 (13) | −0.0011 (11) | 0.0004 (11) | −0.0027 (10) |
C10 | 0.0528 (18) | 0.066 (2) | 0.0356 (15) | 0.0157 (14) | 0.0124 (13) | −0.0090 (13) |
C11 | 0.0515 (18) | 0.0629 (19) | 0.0326 (15) | 0.0018 (14) | −0.0070 (13) | −0.0120 (13) |
C12 | 0.0316 (13) | 0.0255 (14) | 0.0248 (13) | 0.0026 (10) | 0.0027 (10) | −0.0009 (10) |
C13 | 0.0419 (15) | 0.0160 (12) | 0.0336 (13) | 0.0014 (10) | 0.0079 (11) | −0.0019 (9) |
C14 | 0.0357 (14) | 0.0234 (13) | 0.0361 (14) | −0.0012 (10) | 0.0064 (11) | 0.0097 (10) |
O6 | 0.0325 (9) | 0.0272 (9) | 0.0297 (9) | −0.0046 (7) | 0.0040 (7) | 0.0033 (7) |
O7 | 0.0391 (10) | 0.0204 (9) | 0.0287 (9) | 0.0002 (7) | 0.0083 (8) | 0.0003 (6) |
O8 | 0.0484 (11) | 0.0233 (9) | 0.0338 (9) | 0.0002 (7) | 0.0120 (8) | −0.0011 (7) |
O9 | 0.0410 (10) | 0.0211 (9) | 0.0266 (9) | −0.0007 (7) | 0.0093 (7) | 0.0036 (6) |
O10 | 0.0366 (9) | 0.0221 (9) | 0.0275 (9) | 0.0024 (7) | 0.0092 (7) | −0.0009 (6) |
C15 | 0.0199 (11) | 0.0218 (12) | 0.0232 (12) | −0.0026 (9) | 0.0016 (9) | 0.0014 (9) |
C16 | 0.0227 (12) | 0.0173 (12) | 0.0259 (12) | −0.0013 (9) | −0.0022 (9) | 0.0017 (9) |
C17 | 0.0209 (11) | 0.0225 (12) | 0.0241 (12) | −0.0008 (9) | 0.0026 (9) | 0.0007 (9) |
C18 | 0.0230 (12) | 0.0236 (13) | 0.0263 (12) | 0.0004 (9) | 0.0014 (9) | 0.0040 (9) |
C19 | 0.0251 (12) | 0.0173 (12) | 0.0279 (13) | −0.0002 (9) | 0.0018 (10) | −0.0007 (9) |
C20 | 0.0198 (11) | 0.0238 (12) | 0.0229 (12) | −0.0011 (9) | 0.0037 (9) | −0.0013 (9) |
C21 | 0.0207 (12) | 0.0240 (13) | 0.0300 (13) | 0.0028 (9) | 0.0058 (10) | 0.0002 (9) |
C22 | 0.0264 (12) | 0.0306 (13) | 0.0254 (12) | −0.0011 (10) | 0.0026 (10) | −0.0004 (10) |
C23 | 0.0402 (14) | 0.0365 (14) | 0.0244 (12) | −0.0002 (11) | 0.0018 (10) | 0.0045 (10) |
C24 | 0.0565 (19) | 0.070 (2) | 0.0360 (16) | −0.0119 (15) | 0.0125 (14) | 0.0098 (13) |
C25 | 0.0523 (18) | 0.0616 (19) | 0.0359 (15) | −0.0029 (14) | −0.0058 (13) | 0.0113 (13) |
C26 | 0.0324 (13) | 0.0240 (13) | 0.0268 (13) | −0.0011 (10) | 0.0031 (10) | 0.0010 (10) |
C27 | 0.0393 (14) | 0.0184 (12) | 0.0342 (13) | 0.0001 (10) | 0.0083 (11) | 0.0058 (10) |
C28 | 0.0369 (14) | 0.0220 (13) | 0.0347 (14) | 0.0020 (10) | 0.0101 (11) | −0.0028 (10) |
Geometric parameters (Å, º) top
O1—C7 | 1.219 (2) | O6—C21 | 1.221 (2) |
O2—C2 | 1.347 (2) | O7—C16 | 1.353 (2) |
O2—H2 | 0.8400 | O7—H7 | 0.8400 |
O3—C12 | 1.242 (2) | O8—C26 | 1.238 (2) |
O4—C4 | 1.362 (2) | O9—C18 | 1.352 (2) |
O4—C13 | 1.436 (2) | O9—C27 | 1.433 (2) |
O5—C6 | 1.352 (2) | O10—C20 | 1.352 (2) |
O5—C14 | 1.440 (2) | O10—C28 | 1.444 (2) |
C1—C2 | 1.397 (3) | C15—C16 | 1.398 (3) |
C1—C6 | 1.409 (3) | C15—C20 | 1.412 (3) |
C1—C7 | 1.507 (3) | C15—C21 | 1.499 (3) |
C2—C3 | 1.412 (3) | C16—C17 | 1.407 (3) |
C3—C4 | 1.410 (3) | C17—C18 | 1.414 (3) |
C3—C12 | 1.428 (3) | C17—C26 | 1.435 (3) |
C4—C5 | 1.373 (3) | C18—C19 | 1.380 (3) |
C5—C6 | 1.399 (3) | C19—C20 | 1.393 (3) |
C5—H5 | 0.9500 | C19—H19 | 0.9500 |
C7—C8 | 1.509 (3) | C21—C22 | 1.509 (3) |
C8—C9 | 1.529 (3) | C22—C23 | 1.523 (3) |
C8—H8A | 0.9900 | C22—H22A | 0.9900 |
C8—H8B | 0.9900 | C22—H22B | 0.9900 |
C9—C10 | 1.519 (3) | C23—C25 | 1.524 (3) |
C9—C11 | 1.526 (3) | C23—C24 | 1.525 (3) |
C9—H9 | 1.0000 | C23—H23 | 1.0000 |
C10—H10A | 0.9800 | C24—H24A | 0.9800 |
C10—H10B | 0.9800 | C24—H24B | 0.9800 |
C10—H10C | 0.9800 | C24—H24C | 0.9800 |
C11—H11A | 0.9800 | C25—H25A | 0.9800 |
C11—H11B | 0.9800 | C25—H25B | 0.9800 |
C11—H11C | 0.9800 | C25—H25C | 0.9800 |
C12—H12 | 0.9500 | C26—H26 | 0.9500 |
C13—H13A | 0.9800 | C27—H27A | 0.9800 |
C13—H13B | 0.9800 | C27—H27B | 0.9800 |
C13—H13C | 0.9800 | C27—H27C | 0.9800 |
C14—H14A | 0.9800 | C28—H28A | 0.9800 |
C14—H14B | 0.9800 | C28—H28B | 0.9800 |
C14—H14C | 0.9800 | C28—H28C | 0.9800 |
| | | |
C2—O2—H2 | 109.5 | C16—O7—H7 | 109.5 |
C4—O4—C13 | 117.78 (16) | C18—O9—C27 | 118.26 (16) |
C6—O5—C14 | 118.57 (15) | C20—O10—C28 | 118.54 (16) |
C2—C1—C6 | 116.88 (18) | C16—C15—C20 | 116.57 (18) |
C2—C1—C7 | 119.48 (18) | C16—C15—C21 | 119.46 (18) |
C6—C1—C7 | 123.62 (18) | C20—C15—C21 | 123.95 (18) |
O2—C2—C1 | 119.19 (17) | O7—C16—C15 | 119.16 (18) |
O2—C2—C3 | 118.66 (18) | O7—C16—C17 | 118.51 (17) |
C1—C2—C3 | 122.11 (18) | C15—C16—C17 | 122.28 (18) |
C4—C3—C2 | 118.16 (19) | C16—C17—C18 | 118.39 (18) |
C4—C3—C12 | 120.97 (18) | C16—C17—C26 | 121.18 (19) |
C2—C3—C12 | 120.80 (19) | C18—C17—C26 | 120.40 (19) |
O4—C4—C5 | 123.76 (18) | O9—C18—C19 | 124.06 (19) |
O4—C4—C3 | 114.89 (18) | O9—C18—C17 | 115.03 (17) |
C5—C4—C3 | 121.35 (19) | C19—C18—C17 | 120.9 (2) |
C4—C5—C6 | 119.02 (19) | C18—C19—C20 | 119.02 (19) |
C4—C5—H5 | 120.5 | C18—C19—H19 | 120.5 |
C6—C5—H5 | 120.5 | C20—C19—H19 | 120.5 |
O5—C6—C5 | 121.83 (18) | O10—C20—C19 | 121.68 (18) |
O5—C6—C1 | 115.73 (17) | O10—C20—C15 | 115.55 (18) |
C5—C6—C1 | 122.43 (19) | C19—C20—C15 | 122.76 (18) |
O1—C7—C1 | 119.59 (18) | O6—C21—C15 | 119.81 (19) |
O1—C7—C8 | 120.74 (18) | O6—C21—C22 | 120.3 (2) |
C1—C7—C8 | 119.44 (17) | C15—C21—C22 | 119.72 (19) |
C7—C8—C9 | 114.24 (17) | C21—C22—C23 | 114.87 (18) |
C7—C8—H8A | 108.7 | C21—C22—H22A | 108.6 |
C9—C8—H8A | 108.7 | C23—C22—H22A | 108.5 |
C7—C8—H8B | 108.7 | C21—C22—H22B | 108.6 |
C9—C8—H8B | 108.7 | C23—C22—H22B | 108.5 |
H8A—C8—H8B | 107.6 | H22A—C22—H22B | 107.5 |
C10—C9—C11 | 110.3 (2) | C22—C23—C25 | 110.70 (19) |
C10—C9—C8 | 112.0 (2) | C22—C23—C24 | 111.8 (2) |
C11—C9—C8 | 109.98 (19) | C25—C23—C24 | 110.3 (2) |
C10—C9—H9 | 108.1 | C22—C23—H23 | 108.0 |
C11—C9—H9 | 108.1 | C25—C23—H23 | 108.0 |
C8—C9—H9 | 108.1 | C24—C23—H23 | 108.0 |
C9—C10—H10A | 109.5 | C23—C24—H24A | 109.5 |
C9—C10—H10B | 109.5 | C23—C24—H24B | 109.5 |
H10A—C10—H10B | 109.5 | H24A—C24—H24B | 109.5 |
C9—C10—H10C | 109.5 | C23—C24—H24C | 109.5 |
H10A—C10—H10C | 109.5 | H24A—C24—H24C | 109.5 |
H10B—C10—H10C | 109.5 | H24B—C24—H24C | 109.5 |
C9—C11—H11A | 109.5 | C23—C25—H25A | 109.5 |
C9—C11—H11B | 109.5 | C23—C25—H25B | 109.5 |
H11A—C11—H11B | 109.5 | H25A—C25—H25B | 109.5 |
C9—C11—H11C | 109.5 | C23—C25—H25C | 109.5 |
H11A—C11—H11C | 109.5 | H25A—C25—H25C | 109.5 |
H11B—C11—H11C | 109.5 | H25B—C25—H25C | 109.5 |
O3—C12—C3 | 124.16 (19) | O8—C26—C17 | 124.1 (2) |
O3—C12—H12 | 117.9 | O8—C26—H26 | 117.9 |
C3—C12—H12 | 117.9 | C17—C26—H26 | 117.9 |
O4—C13—H13A | 109.5 | O9—C27—H27A | 109.5 |
O4—C13—H13B | 109.5 | O9—C27—H27B | 109.5 |
H13A—C13—H13B | 109.5 | H27A—C27—H27B | 109.5 |
O4—C13—H13C | 109.5 | O9—C27—H27C | 109.5 |
H13A—C13—H13C | 109.5 | H27A—C27—H27C | 109.5 |
H13B—C13—H13C | 109.5 | H27B—C27—H27C | 109.5 |
O5—C14—H14A | 109.5 | O10—C28—H28A | 109.5 |
O5—C14—H14B | 109.5 | O10—C28—H28B | 109.5 |
H14A—C14—H14B | 109.5 | H28A—C28—H28B | 109.5 |
O5—C14—H14C | 109.5 | O10—C28—H28C | 109.5 |
H14A—C14—H14C | 109.5 | H28A—C28—H28C | 109.5 |
H14B—C14—H14C | 109.5 | H28B—C28—H28C | 109.5 |
| | | |
C6—C1—C2—O2 | −179.03 (17) | C20—C15—C16—O7 | 179.48 (17) |
C7—C1—C2—O2 | −0.6 (3) | C21—C15—C16—O7 | 0.7 (3) |
C6—C1—C2—C3 | −1.2 (3) | C20—C15—C16—C17 | 2.3 (3) |
C7—C1—C2—C3 | 177.19 (18) | C21—C15—C16—C17 | −176.54 (19) |
O2—C2—C3—C4 | 178.45 (17) | O7—C16—C17—C18 | −178.50 (17) |
C1—C2—C3—C4 | 0.6 (3) | C15—C16—C17—C18 | −1.3 (3) |
O2—C2—C3—C12 | 1.4 (3) | O7—C16—C17—C26 | −0.4 (3) |
C1—C2—C3—C12 | −176.38 (19) | C15—C16—C17—C26 | 176.9 (2) |
C13—O4—C4—C5 | −2.2 (3) | C27—O9—C18—C19 | 1.1 (3) |
C13—O4—C4—C3 | 177.79 (17) | C27—O9—C18—C17 | −178.63 (17) |
C2—C3—C4—O4 | −178.95 (18) | C16—C17—C18—O9 | 178.69 (18) |
C12—C3—C4—O4 | −2.0 (3) | C26—C17—C18—O9 | 0.5 (3) |
C2—C3—C4—C5 | 1.1 (3) | C16—C17—C18—C19 | −1.1 (3) |
C12—C3—C4—C5 | 178.1 (2) | C26—C17—C18—C19 | −179.2 (2) |
O4—C4—C5—C6 | 177.98 (18) | O9—C18—C19—C20 | −177.46 (18) |
C3—C4—C5—C6 | −2.0 (3) | C17—C18—C19—C20 | 2.3 (3) |
C14—O5—C6—C5 | −2.1 (3) | C28—O10—C20—C19 | 1.9 (3) |
C14—O5—C6—C1 | 177.01 (17) | C28—O10—C20—C15 | −177.38 (17) |
C4—C5—C6—O5 | −179.51 (18) | C18—C19—C20—O10 | 179.49 (18) |
C4—C5—C6—C1 | 1.4 (3) | C18—C19—C20—C15 | −1.2 (3) |
C2—C1—C6—O5 | −178.94 (18) | C16—C15—C20—O10 | 178.30 (18) |
C7—C1—C6—O5 | 2.7 (3) | C21—C15—C20—O10 | −2.9 (3) |
C2—C1—C6—C5 | 0.2 (3) | C16—C15—C20—C19 | −1.0 (3) |
C7—C1—C6—C5 | −178.13 (19) | C21—C15—C20—C19 | 177.7 (2) |
C2—C1—C7—O1 | 41.0 (3) | C16—C15—C21—O6 | −41.3 (3) |
C6—C1—C7—O1 | −140.7 (2) | C20—C15—C21—O6 | 139.9 (2) |
C2—C1—C7—C8 | −133.5 (2) | C16—C15—C21—C22 | 134.1 (2) |
C6—C1—C7—C8 | 44.7 (3) | C20—C15—C21—C22 | −44.6 (3) |
O1—C7—C8—C9 | −10.0 (3) | O6—C21—C22—C23 | 10.5 (3) |
C1—C7—C8—C9 | 164.52 (19) | C15—C21—C22—C23 | −164.97 (18) |
C7—C8—C9—C10 | 76.1 (3) | C21—C22—C23—C25 | 160.6 (2) |
C7—C8—C9—C11 | −160.9 (2) | C21—C22—C23—C24 | −76.0 (3) |
C4—C3—C12—O3 | −178.41 (19) | C16—C17—C26—O8 | 0.9 (3) |
C2—C3—C12—O3 | −1.5 (3) | C18—C17—C26—O8 | 178.94 (19) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2···O3 | 0.84 | 1.79 | 2.549 (2) | 149 |
O7—H7···O8 | 0.84 | 1.80 | 2.558 (2) | 149 |
C8—H8A···O10i | 0.99 | 2.57 | 3.372 (3) | 139 |
C14—H14C···O6i | 0.98 | 2.52 | 3.277 (3) | 134 |
C22—H22B···O5 | 0.99 | 2.57 | 3.371 (3) | 138 |
C28—H28A···O1 | 0.98 | 2.52 | 3.277 (3) | 134 |
C12—H12···O8ii | 0.95 | 2.47 | 3.337 (3) | 152 |
C27—H27B···O3iii | 0.98 | 2.52 | 3.492 (3) | 170 |
Symmetry codes: (i) x+1, y, z; (ii) −x+1, −y+1, −z; (iii) −x+1, −y+2, −z. |
Experimental details
Crystal data |
Chemical formula | C14H18O5 |
Mr | 266.28 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 160 |
a, b, c (Å) | 7.2946 (10), 8.2775 (13), 22.400 (3) |
α, β, γ (°) | 95.949 (6), 99.410 (8), 90.099 (6) |
V (Å3) | 1326.9 (3) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.10 |
Crystal size (mm) | 0.50 × 0.22 × 0.16 |
|
Data collection |
Diffractometer | Siemens SMART 1K CCD diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 19412, 5830, 3128 |
Rint | 0.067 |
(sin θ/λ)max (Å−1) | 0.649 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.051, 0.131, 0.97 |
No. of reflections | 5830 |
No. of parameters | 353 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.23, −0.24 |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2···O3 | 0.84 | 1.79 | 2.549 (2) | 149 |
O7—H7···O8 | 0.84 | 1.80 | 2.558 (2) | 149 |
C8—H8A···O10i | 0.99 | 2.57 | 3.372 (3) | 139 |
C14—H14C···O6i | 0.98 | 2.52 | 3.277 (3) | 134 |
C22—H22B···O5 | 0.99 | 2.57 | 3.371 (3) | 138 |
C28—H28A···O1 | 0.98 | 2.52 | 3.277 (3) | 134 |
C12—H12···O8ii | 0.95 | 2.47 | 3.337 (3) | 152 |
C27—H27B···O3iii | 0.98 | 2.52 | 3.492 (3) | 170 |
Symmetry codes: (i) x+1, y, z; (ii) −x+1, −y+1, −z; (iii) −x+1, −y+2, −z. |
The title compound, (I), was obtained by a Friedel–Crafts acylation reaction of 4,6-dimethoxysalicylaldehyde with 3-methylbutyric acid chloride (Reggelin et al., 1999). Only one of two possible regioisomers was obtained. The constitution of (I) could not be determined by HMBC correlations (Bax & Summers, 1986). Only after the application of 1,n-ADEQUATE experiments (Reif et al., 1996) was pit ossible to ascertain the substitution pattern (Köck et al., 1996). To corroborate the results from the NMR studies, a crystal structure analysis of (I) was performed.
The structure contains two independent molecules (A and B). They are illustrated in Fig. 1. The dimensions of the two molecules are very similar. The r.m.s. deviation of a least-squares fit of the non-H atoms is 0.011 Å. In each of the molecules, there is an intramolecular O—H···O hydrogen bond between the hydroxyl group and the aldehyde group (Table 1). The aldehyde and the two methoxy groups are almost coplanar with the benzene plane. The angle between the plane of the benzene ring and the plane of the keto group attached to C1 (or C15) is 43.6 (1)° for both molecules. This nonplanar orientation is required to avoid a short repulsive contact between atoms O1 and O2 (or between O6 and O7).
The crystal structure shows stacks of molecules along the crystallographic a-axis direction. The order of the molecules in the stack is ABAB etc., as shown in Fig. 2. The interplanar angle between the benzene rings of molecules A and B is 1.6 (1)°. The perpendicular distance between the planes, defined as the shortest distance of a ring centroid to the plane of the adjacent ring, ranges from 3.399 to 3.417 Å. There is an offset of 1.38 Å [are s.u. values available (also in abstract)?] between the centroids of neighboring rings. There are intermolecular π–π contacts between neighboring benzaldehyde groups. The shortest intermolecular C(π)···C(π) distances are between 3.335 (3) and 3.428 (3) Å and are illustrated in Fig. 2 as broken lines. Those involving the aldehyde C atoms are slightly shorter than the perpendicular distances between the benzene planes. The molecules in the stack are also connected by four intermolecular C—H···O interactions (Table 1, entries 3 to 6) with H···O distances between 2.52 and 2.57 Å (also shown in Fig. 2). The stacks are connected by additional intermolecular C—H···O contacts (Table 1, entries 7 and 8), with H···O distances of 2.47 and 2.52 Å, to bilayers parallel to the [001] plane, as shown in Fig. 3. There are also four intermolecular Oketo···Cmethoxy interactions, with O···C distances of 2.910 (2), 2.929 (2), 3.015 (2) and 3.019 (2) Å, which connect the stacks in the b-axis direction. These O···C distances are significantly shorter than the van der Waals contact distance of 3.22 Å (Bondi, 1964), and the C═O···C and O···C—O angles are almost linear. No significant interactions are observed between neighboring bilayers in the c-axis direction.
The two molecules are related by pseudo-symmetry. Inspection of the fractional coordinates shows the two molecules to be related by the pseudo-relationship xA=xB + 1/2, yA = 1.257 - yB + 0.539zB and zA = zB. This is a local noncrystallographic a-glide plane perpendicular to the b axis, intersecting the b axis at positions y = 0.128 and y = 0.628, as shown in Fig. 3. The pseudo-glide plane is continuous in the crystallographic a-axis direction, resulting in a value of the unit-cell angle γ of approximately 90°. In the c-axis direction, the pseudo-glide plane acts only in one unit cell and shows discontinuities at z = 0 and z = 1. Similar pseudo-symmetry has been observed by us in other crystal structures (Bats, Hoyer & Mulzer, 1999; Bats, Öhlinger & Mulzer, 1999).