access
O hydrogen bonds with O
O distances in the range 2.6750 (17)-2.8160 (18) Å.Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S160053680903829X/pv2210sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S160053680903829X/pv2210Isup2.hkl |
CCDC reference: 750786
Isolation of the title compound from Lactuca floridana has been described (Bohlmann et al., 1981; Song et al., 1995). Crystals were grown by evaporation from ethyl acetate.
H atoms on C were placed in idealized positions with C—H distances 0.95 - 1.00 Å and thereafter treated as riding. Coordinates for the H atoms on O were refined. Uiso for H was assigned as 1.2 times Ueq of the attached atoms (1.5 for methyl and OH). A torsional parameter was refined for each methyl group.
Data collection: APEX2 (Bruker, 2006); cell refinement: APEX2 (Bruker, 2006); data reduction: APEX2 (Bruker, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).
| Fig. 1. Ellipsoids at the 50% probability level, with H atoms having arbitrary radius. Both molecules are shown in the same orientation. |
| C17H20O6·0.5H2O | F(000) = 700 |
| Mr = 329.34 | Dx = 1.375 Mg m−3 |
| Monoclinic, P21 | Cu Kα radiation, λ = 1.54178 Å |
| Hall symbol: P 2yb | Cell parameters from 9656 reflections |
| a = 10.9276 (5) Å | θ = 2.3–68.3° |
| b = 7.4658 (5) Å | µ = 0.88 mm−1 |
| c = 19.8571 (10) Å | T = 90 K |
| β = 100.850 (5)° | Plate, colorless |
| V = 1591.05 (15) Å3 | 0.27 × 0.17 × 0.10 mm |
| Z = 4 |
| Bruker Kappa APEXII CCD area-detector diffractometer | 5642 independent reflections |
| Radiation source: fine-focus sealed tube | 5513 reflections with I > 2σ(I) |
| Graphite monochromator | Rint = 0.031 |
| ϕ and ω scans | θmax = 69.0°, θmin = 2.3° |
| Absorption correction: multi-scan (SADABS; Sheldrick, 2004) | h = −12→13 |
| Tmin = 0.796, Tmax = 0.917 | k = −9→8 |
| 23565 measured reflections | l = −23→23 |
| Refinement on F2 | Hydrogen site location: inferred from neighbouring sites |
| Least-squares matrix: full | H atoms treated by a mixture of independent and constrained refinement |
| R[F2 > 2σ(F2)] = 0.027 | w = 1/[σ2(Fo2) + (0.0314P)2 + 0.4082P] where P = (Fo2 + 2Fc2)/3 |
| wR(F2) = 0.068 | (Δ/σ)max = 0.001 |
| S = 1.03 | Δρmax = 0.20 e Å−3 |
| 5642 reflections | Δρmin = −0.14 e Å−3 |
| 445 parameters | Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
| 1 restraint | Extinction coefficient: 0.00101 (13) |
| Primary atom site location: structure-invariant direct methods | Absolute structure: Flack (1983), 2516 Friedel pairs |
| Secondary atom site location: difference Fourier map | Absolute structure parameter: −0.01 (10) |
| C17H20O6·0.5H2O | V = 1591.05 (15) Å3 |
| Mr = 329.34 | Z = 4 |
| Monoclinic, P21 | Cu Kα radiation |
| a = 10.9276 (5) Å | µ = 0.88 mm−1 |
| b = 7.4658 (5) Å | T = 90 K |
| c = 19.8571 (10) Å | 0.27 × 0.17 × 0.10 mm |
| β = 100.850 (5)° |
| Bruker Kappa APEXII CCD area-detector diffractometer | 5642 independent reflections |
| Absorption correction: multi-scan (SADABS; Sheldrick, 2004) | 5513 reflections with I > 2σ(I) |
| Tmin = 0.796, Tmax = 0.917 | Rint = 0.031 |
| 23565 measured reflections |
| R[F2 > 2σ(F2)] = 0.027 | H atoms treated by a mixture of independent and constrained refinement |
| wR(F2) = 0.068 | Δρmax = 0.20 e Å−3 |
| S = 1.03 | Δρmin = −0.14 e Å−3 |
| 5642 reflections | Absolute structure: Flack (1983), 2516 Friedel pairs |
| 445 parameters | Absolute structure parameter: −0.01 (10) |
| 1 restraint |
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. |
| x | y | z | Uiso*/Ueq | ||
| O1 | 0.36074 (9) | 0.72760 (16) | 0.04034 (5) | 0.0256 (2) | |
| O2 | 0.54683 (12) | 0.8177 (2) | 0.02323 (6) | 0.0473 (4) | |
| O3 | −0.15403 (9) | 0.63628 (15) | 0.05240 (5) | 0.0255 (2) | |
| O4 | 0.19069 (10) | 0.67077 (15) | −0.19419 (5) | 0.0240 (2) | |
| O5 | 0.07993 (12) | 0.91019 (18) | −0.23883 (6) | 0.0345 (3) | |
| O6 | 0.25725 (10) | 0.54254 (16) | 0.22516 (5) | 0.0252 (2) | |
| H6O | 0.2544 (19) | 0.651 (3) | 0.2400 (10) | 0.038* | |
| C1 | 0.02479 (13) | 0.5810 (2) | −0.00331 (8) | 0.0203 (3) | |
| C2 | −0.04236 (14) | 0.61236 (19) | 0.05490 (7) | 0.0211 (3) | |
| C3 | 0.05145 (14) | 0.6056 (2) | 0.11802 (7) | 0.0216 (3) | |
| H3 | 0.0338 | 0.6189 | 0.1628 | 0.026* | |
| C4 | 0.16502 (14) | 0.5782 (2) | 0.10450 (7) | 0.0196 (3) | |
| C5 | 0.16294 (13) | 0.5614 (2) | 0.02770 (7) | 0.0191 (3) | |
| H5 | 0.1933 | 0.4402 | 0.0170 | 0.023* | |
| C6 | 0.23650 (13) | 0.7063 (2) | −0.00135 (6) | 0.0201 (3) | |
| H6 | 0.1907 | 0.8225 | −0.0025 | 0.024* | |
| C7 | 0.26251 (13) | 0.6665 (2) | −0.07304 (7) | 0.0210 (3) | |
| H7 | 0.2901 | 0.5390 | −0.0742 | 0.025* | |
| C8 | 0.14873 (13) | 0.6930 (2) | −0.12911 (6) | 0.0210 (3) | |
| H8 | 0.1133 | 0.8156 | −0.1260 | 0.025* | |
| C9 | 0.04910 (14) | 0.5504 (2) | −0.12638 (7) | 0.0221 (3) | |
| H9A | −0.0085 | 0.5477 | −0.1713 | 0.026* | |
| H9B | 0.0903 | 0.4319 | −0.1195 | 0.026* | |
| C10 | −0.02665 (14) | 0.5780 (2) | −0.07062 (7) | 0.0210 (3) | |
| C11 | 0.37468 (16) | 0.7875 (3) | −0.07459 (8) | 0.0334 (4) | |
| H11 | 0.3446 | 0.9122 | −0.0861 | 0.040* | |
| C12 | 0.44090 (16) | 0.7817 (3) | −0.00012 (8) | 0.0327 (4) | |
| C13 | 0.46307 (17) | 0.7337 (4) | −0.12182 (9) | 0.0504 (6) | |
| H13A | 0.5417 | 0.7993 | −0.1089 | 0.076* | |
| H13B | 0.4252 | 0.7625 | −0.1693 | 0.076* | |
| H13C | 0.4793 | 0.6047 | −0.1177 | 0.076* | |
| C14 | −0.16387 (14) | 0.5988 (2) | −0.09751 (8) | 0.0238 (3) | |
| H14A | −0.2067 | 0.6226 | −0.0593 | 0.036* | |
| H14B | −0.1967 | 0.4884 | −0.1209 | 0.036* | |
| H14C | −0.1778 | 0.6990 | −0.1299 | 0.036* | |
| C15 | 0.28150 (14) | 0.5536 (2) | 0.15730 (7) | 0.0232 (3) | |
| H15A | 0.3241 | 0.4427 | 0.1469 | 0.028* | |
| H15B | 0.3384 | 0.6554 | 0.1546 | 0.028* | |
| C16 | 0.14984 (13) | 0.7902 (2) | −0.24440 (7) | 0.0212 (3) | |
| C17 | 0.20561 (16) | 0.7550 (2) | −0.30617 (7) | 0.0298 (4) | |
| H17A | 0.1449 | 0.7846 | −0.3476 | 0.045* | |
| H17B | 0.2283 | 0.6282 | −0.3073 | 0.045* | |
| H17C | 0.2803 | 0.8290 | −0.3042 | 0.045* | |
| O1A | 0.10059 (9) | 0.30940 (15) | 0.46612 (5) | 0.0229 (2) | |
| O2A | −0.08856 (10) | 0.34776 (18) | 0.49033 (5) | 0.0320 (3) | |
| O3A | 0.61587 (9) | 0.19216 (15) | 0.43180 (5) | 0.0258 (2) | |
| O4A | 0.29523 (9) | 0.22296 (15) | 0.69401 (5) | 0.0214 (2) | |
| O5A | 0.45039 (11) | 0.39546 (17) | 0.74928 (5) | 0.0320 (3) | |
| O6A | 0.18713 (10) | 0.21622 (16) | 0.27100 (5) | 0.0258 (2) | |
| H60A | 0.2039 (19) | 0.317 (3) | 0.2552 (10) | 0.039* | |
| C1A | 0.44199 (13) | 0.17797 (19) | 0.49391 (7) | 0.0188 (3) | |
| C2A | 0.50439 (13) | 0.1995 (2) | 0.43344 (7) | 0.0205 (3) | |
| C3A | 0.40492 (14) | 0.2229 (2) | 0.37344 (7) | 0.0215 (3) | |
| H3A | 0.4187 | 0.2443 | 0.3283 | 0.026* | |
| C4A | 0.29305 (13) | 0.2106 (2) | 0.39010 (7) | 0.0199 (3) | |
| C5A | 0.30176 (13) | 0.1693 (2) | 0.46618 (7) | 0.0190 (3) | |
| H5A | 0.2720 | 0.0442 | 0.4712 | 0.023* | |
| C6A | 0.22888 (13) | 0.2972 (2) | 0.50361 (7) | 0.0191 (3) | |
| H6A | 0.2685 | 0.4184 | 0.5069 | 0.023* | |
| C7A | 0.21326 (12) | 0.2344 (2) | 0.57504 (6) | 0.0196 (3) | |
| H7A | 0.1957 | 0.1028 | 0.5728 | 0.024* | |
| C8A | 0.33015 (13) | 0.2662 (2) | 0.62853 (7) | 0.0194 (3) | |
| H8A | 0.3582 | 0.3935 | 0.6277 | 0.023* | |
| C9A | 0.43475 (14) | 0.1374 (2) | 0.61948 (7) | 0.0215 (3) | |
| H91A | 0.4979 | 0.1383 | 0.6624 | 0.026* | |
| H92A | 0.3995 | 0.0150 | 0.6138 | 0.026* | |
| C10A | 0.50089 (13) | 0.17411 (19) | 0.56004 (7) | 0.0193 (3) | |
| C11A | 0.09343 (13) | 0.3330 (2) | 0.58339 (7) | 0.0250 (3) | |
| H11A | 0.1154 | 0.4596 | 0.5969 | 0.030* | |
| C12A | 0.02146 (14) | 0.3323 (2) | 0.51022 (7) | 0.0243 (3) | |
| C13A | 0.01788 (14) | 0.2562 (3) | 0.63306 (8) | 0.0307 (4) | |
| H13D | −0.0645 | 0.3130 | 0.6254 | 0.046* | |
| H13E | 0.0609 | 0.2793 | 0.6802 | 0.046* | |
| H13F | 0.0083 | 0.1268 | 0.6257 | 0.046* | |
| C14A | 0.63888 (13) | 0.2030 (2) | 0.58228 (7) | 0.0230 (3) | |
| H14D | 0.6761 | 0.2265 | 0.5420 | 0.034* | |
| H14E | 0.6768 | 0.0957 | 0.6059 | 0.034* | |
| H14F | 0.6535 | 0.3057 | 0.6135 | 0.034* | |
| C15A | 0.17124 (13) | 0.2246 (2) | 0.34040 (7) | 0.0231 (3) | |
| H15C | 0.1158 | 0.1259 | 0.3492 | 0.028* | |
| H15D | 0.1303 | 0.3391 | 0.3481 | 0.028* | |
| C16A | 0.36493 (14) | 0.2941 (2) | 0.75074 (7) | 0.0233 (3) | |
| C17A | 0.32219 (17) | 0.2309 (3) | 0.81365 (8) | 0.0351 (4) | |
| H17D | 0.3798 | 0.2738 | 0.8543 | 0.053* | |
| H17E | 0.3202 | 0.0996 | 0.8140 | 0.053* | |
| H17F | 0.2385 | 0.2776 | 0.8140 | 0.053* | |
| O7 | 0.29309 (12) | 0.89082 (18) | 0.25390 (6) | 0.0333 (3) | |
| H72 | 0.371 (2) | 0.911 (3) | 0.2489 (11) | 0.050 (6)* | |
| H71 | 0.259 (3) | 0.997 (4) | 0.2573 (14) | 0.077 (9)* |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| O1 | 0.0262 (5) | 0.0319 (6) | 0.0171 (5) | −0.0085 (5) | 0.0001 (4) | 0.0013 (4) |
| O2 | 0.0361 (7) | 0.0768 (11) | 0.0268 (6) | −0.0292 (7) | 0.0006 (5) | 0.0032 (7) |
| O3 | 0.0234 (5) | 0.0289 (6) | 0.0248 (5) | −0.0002 (4) | 0.0058 (4) | −0.0015 (4) |
| O4 | 0.0331 (6) | 0.0249 (6) | 0.0143 (5) | 0.0018 (5) | 0.0053 (4) | 0.0022 (4) |
| O5 | 0.0432 (7) | 0.0384 (7) | 0.0231 (5) | 0.0132 (6) | 0.0097 (5) | 0.0106 (5) |
| O6 | 0.0346 (6) | 0.0261 (6) | 0.0145 (5) | 0.0005 (5) | 0.0035 (4) | 0.0008 (4) |
| C1 | 0.0237 (8) | 0.0170 (7) | 0.0196 (7) | −0.0023 (6) | 0.0025 (6) | 0.0017 (6) |
| C2 | 0.0261 (8) | 0.0147 (7) | 0.0224 (7) | −0.0015 (6) | 0.0041 (6) | 0.0002 (6) |
| C3 | 0.0297 (8) | 0.0192 (8) | 0.0165 (7) | −0.0003 (6) | 0.0055 (6) | −0.0001 (6) |
| C4 | 0.0268 (8) | 0.0164 (7) | 0.0154 (7) | 0.0000 (6) | 0.0032 (6) | 0.0011 (6) |
| C5 | 0.0244 (7) | 0.0184 (8) | 0.0139 (7) | 0.0004 (6) | 0.0021 (5) | 0.0003 (5) |
| C6 | 0.0224 (7) | 0.0216 (8) | 0.0142 (6) | −0.0019 (6) | −0.0020 (5) | 0.0007 (6) |
| C7 | 0.0254 (7) | 0.0225 (8) | 0.0150 (6) | −0.0038 (6) | 0.0035 (5) | 0.0024 (6) |
| C8 | 0.0298 (7) | 0.0210 (8) | 0.0126 (6) | 0.0001 (6) | 0.0053 (5) | 0.0000 (6) |
| C9 | 0.0247 (7) | 0.0251 (8) | 0.0149 (7) | −0.0012 (6) | −0.0003 (6) | −0.0013 (6) |
| C10 | 0.0261 (8) | 0.0172 (7) | 0.0191 (7) | −0.0012 (6) | 0.0025 (6) | 0.0003 (6) |
| C11 | 0.0371 (9) | 0.0417 (10) | 0.0199 (7) | −0.0173 (8) | 0.0014 (6) | 0.0049 (7) |
| C12 | 0.0346 (9) | 0.0399 (10) | 0.0225 (8) | −0.0161 (8) | 0.0025 (7) | 0.0027 (7) |
| C13 | 0.0353 (9) | 0.0924 (17) | 0.0248 (8) | −0.0282 (11) | 0.0085 (7) | 0.0021 (10) |
| C14 | 0.0266 (8) | 0.0233 (8) | 0.0198 (7) | −0.0003 (6) | 0.0000 (6) | 0.0008 (6) |
| C15 | 0.0267 (8) | 0.0270 (8) | 0.0154 (7) | 0.0020 (6) | 0.0029 (6) | 0.0001 (6) |
| C16 | 0.0230 (7) | 0.0226 (8) | 0.0165 (7) | −0.0048 (6) | −0.0002 (5) | 0.0024 (6) |
| C17 | 0.0395 (9) | 0.0320 (10) | 0.0186 (7) | 0.0007 (7) | 0.0070 (6) | 0.0023 (6) |
| O1A | 0.0214 (5) | 0.0301 (6) | 0.0166 (5) | 0.0057 (4) | 0.0020 (4) | 0.0010 (4) |
| O2A | 0.0241 (6) | 0.0444 (7) | 0.0266 (6) | 0.0095 (5) | 0.0026 (4) | 0.0035 (5) |
| O3A | 0.0242 (5) | 0.0290 (6) | 0.0256 (5) | 0.0001 (5) | 0.0086 (4) | 0.0015 (5) |
| O4A | 0.0243 (5) | 0.0254 (5) | 0.0145 (4) | −0.0015 (4) | 0.0037 (4) | −0.0016 (4) |
| O5A | 0.0313 (6) | 0.0398 (7) | 0.0234 (5) | −0.0079 (5) | 0.0013 (4) | −0.0044 (5) |
| O6A | 0.0361 (6) | 0.0262 (6) | 0.0147 (5) | 0.0022 (5) | 0.0042 (4) | −0.0005 (5) |
| C1A | 0.0223 (7) | 0.0138 (7) | 0.0205 (7) | 0.0005 (6) | 0.0045 (5) | 0.0003 (6) |
| C2A | 0.0254 (7) | 0.0155 (8) | 0.0214 (7) | 0.0001 (6) | 0.0062 (5) | −0.0007 (6) |
| C3A | 0.0301 (7) | 0.0187 (7) | 0.0165 (6) | −0.0012 (6) | 0.0066 (5) | 0.0000 (6) |
| C4A | 0.0284 (7) | 0.0144 (7) | 0.0167 (6) | 0.0002 (6) | 0.0035 (5) | −0.0021 (6) |
| C5A | 0.0227 (7) | 0.0172 (7) | 0.0169 (6) | 0.0001 (6) | 0.0029 (5) | 0.0004 (6) |
| C6A | 0.0193 (7) | 0.0208 (7) | 0.0162 (6) | 0.0012 (6) | 0.0008 (5) | 0.0007 (6) |
| C7A | 0.0214 (7) | 0.0223 (8) | 0.0152 (6) | −0.0007 (6) | 0.0038 (5) | −0.0006 (6) |
| C8A | 0.0226 (7) | 0.0225 (8) | 0.0132 (6) | −0.0001 (6) | 0.0037 (5) | 0.0007 (5) |
| C9A | 0.0236 (7) | 0.0225 (8) | 0.0178 (7) | 0.0016 (6) | 0.0019 (5) | 0.0014 (6) |
| C10A | 0.0235 (7) | 0.0140 (7) | 0.0208 (7) | 0.0027 (6) | 0.0052 (5) | −0.0004 (6) |
| C11A | 0.0233 (7) | 0.0327 (9) | 0.0184 (7) | 0.0047 (7) | 0.0021 (6) | −0.0023 (6) |
| C12A | 0.0266 (8) | 0.0247 (8) | 0.0220 (7) | 0.0054 (6) | 0.0056 (6) | −0.0002 (6) |
| C13A | 0.0263 (8) | 0.0437 (11) | 0.0233 (7) | 0.0063 (7) | 0.0080 (6) | 0.0039 (7) |
| C14A | 0.0247 (7) | 0.0212 (8) | 0.0224 (7) | −0.0011 (6) | 0.0029 (5) | −0.0007 (6) |
| C15A | 0.0283 (8) | 0.0249 (8) | 0.0157 (6) | 0.0001 (7) | 0.0035 (5) | −0.0009 (6) |
| C16A | 0.0250 (7) | 0.0257 (8) | 0.0183 (7) | 0.0049 (7) | 0.0013 (6) | −0.0024 (6) |
| C17A | 0.0450 (9) | 0.0429 (10) | 0.0175 (7) | −0.0045 (9) | 0.0059 (6) | −0.0025 (7) |
| O7 | 0.0351 (7) | 0.0283 (7) | 0.0353 (6) | 0.0043 (6) | 0.0031 (5) | −0.0038 (5) |
| O1—C12 | 1.3568 (19) | O1A—C6A | 1.4612 (16) |
| O1—C6 | 1.4597 (16) | O2A—C12A | 1.1982 (19) |
| O2—C12 | 1.194 (2) | O3A—C2A | 1.2259 (18) |
| O3—C2 | 1.2251 (19) | O4A—C16A | 1.3445 (18) |
| O4—C16 | 1.3496 (18) | O4A—C8A | 1.4586 (16) |
| O4—C8 | 1.4598 (16) | O5A—C16A | 1.207 (2) |
| O5—C16 | 1.196 (2) | O6A—C15A | 1.4224 (16) |
| O6—C15 | 1.4238 (17) | O6A—H60A | 0.85 (2) |
| O6—H6O | 0.86 (2) | C1A—C10A | 1.349 (2) |
| C1—C10 | 1.349 (2) | C1A—C2A | 1.4969 (19) |
| C1—C2 | 1.500 (2) | C1A—C5A | 1.5291 (19) |
| C1—C5 | 1.5264 (19) | C2A—C3A | 1.4644 (19) |
| C2—C3 | 1.463 (2) | C3A—C4A | 1.328 (2) |
| C3—C4 | 1.334 (2) | C3A—H3A | 0.9500 |
| C3—H3 | 0.9500 | C4A—C15A | 1.5041 (19) |
| C4—C15 | 1.500 (2) | C4A—C5A | 1.5271 (18) |
| C4—C5 | 1.5261 (19) | C5A—C6A | 1.5238 (19) |
| C5—C6 | 1.525 (2) | C5A—H5A | 1.0000 |
| C5—H5 | 1.0000 | C6A—C7A | 1.5337 (18) |
| C6—C7 | 1.5323 (18) | C6A—H6A | 1.0000 |
| C6—H6 | 1.0000 | C7A—C8A | 1.5182 (19) |
| C7—C8 | 1.5177 (19) | C7A—C11A | 1.538 (2) |
| C7—C11 | 1.527 (2) | C7A—H7A | 1.0000 |
| C7—H7 | 1.0000 | C8A—C9A | 1.530 (2) |
| C8—C9 | 1.531 (2) | C8A—H8A | 1.0000 |
| C8—H8 | 1.0000 | C9A—C10A | 1.5206 (19) |
| C9—C10 | 1.516 (2) | C9A—H91A | 0.9900 |
| C9—H9A | 0.9900 | C9A—H92A | 0.9900 |
| C9—H9B | 0.9900 | C10A—C14A | 1.505 (2) |
| C10—C14 | 1.502 (2) | C11A—C13A | 1.513 (2) |
| C11—C12 | 1.520 (2) | C11A—C12A | 1.517 (2) |
| C11—C13 | 1.521 (3) | C11A—H11A | 1.0000 |
| C11—H11 | 1.0000 | C13A—H13D | 0.9800 |
| C13—H13A | 0.9800 | C13A—H13E | 0.9800 |
| C13—H13B | 0.9800 | C13A—H13F | 0.9800 |
| C13—H13C | 0.9800 | C14A—H14D | 0.9800 |
| C14—H14A | 0.9800 | C14A—H14E | 0.9800 |
| C14—H14B | 0.9800 | C14A—H14F | 0.9800 |
| C14—H14C | 0.9800 | C15A—H15C | 0.9900 |
| C15—H15A | 0.9900 | C15A—H15D | 0.9900 |
| C15—H15B | 0.9900 | C16A—C17A | 1.490 (2) |
| C16—C17 | 1.492 (2) | C17A—H17D | 0.9800 |
| C17—H17A | 0.9800 | C17A—H17E | 0.9800 |
| C17—H17B | 0.9800 | C17A—H17F | 0.9800 |
| C17—H17C | 0.9800 | O7—H72 | 0.89 (2) |
| O1A—C12A | 1.3524 (18) | O7—H71 | 0.89 (3) |
| C12—O1—C6 | 109.37 (11) | C16A—O4A—C8A | 117.23 (11) |
| C16—O4—C8 | 117.62 (11) | C15A—O6A—H60A | 113.1 (14) |
| C15—O6—H6O | 107.0 (14) | C10A—C1A—C2A | 125.23 (13) |
| C10—C1—C2 | 126.38 (13) | C10A—C1A—C5A | 127.71 (13) |
| C10—C1—C5 | 126.46 (13) | C2A—C1A—C5A | 107.01 (11) |
| C2—C1—C5 | 107.11 (12) | O3A—C2A—C3A | 124.94 (13) |
| O3—C2—C3 | 124.87 (13) | O3A—C2A—C1A | 128.43 (13) |
| O3—C2—C1 | 128.30 (13) | C3A—C2A—C1A | 106.56 (11) |
| C3—C2—C1 | 106.82 (12) | C4A—C3A—C2A | 111.47 (12) |
| C4—C3—C2 | 111.18 (13) | C4A—C3A—H3A | 124.3 |
| C4—C3—H3 | 124.4 | C2A—C3A—H3A | 124.3 |
| C2—C3—H3 | 124.4 | C3A—C4A—C15A | 125.03 (12) |
| C3—C4—C15 | 125.26 (13) | C3A—C4A—C5A | 111.81 (12) |
| C3—C4—C5 | 111.98 (13) | C15A—C4A—C5A | 123.08 (12) |
| C15—C4—C5 | 122.64 (13) | C6A—C5A—C4A | 114.51 (12) |
| C6—C5—C4 | 114.20 (12) | C6A—C5A—C1A | 112.21 (11) |
| C6—C5—C1 | 109.34 (11) | C4A—C5A—C1A | 102.67 (11) |
| C4—C5—C1 | 102.88 (11) | C6A—C5A—H5A | 109.1 |
| C6—C5—H5 | 110.1 | C4A—C5A—H5A | 109.1 |
| C4—C5—H5 | 110.1 | C1A—C5A—H5A | 109.1 |
| C1—C5—H5 | 110.1 | O1A—C6A—C5A | 109.26 (11) |
| O1—C6—C5 | 111.28 (11) | O1A—C6A—C7A | 103.13 (11) |
| O1—C6—C7 | 103.45 (11) | C5A—C6A—C7A | 114.76 (12) |
| C5—C6—C7 | 114.66 (12) | O1A—C6A—H6A | 109.8 |
| O1—C6—H6 | 109.1 | C5A—C6A—H6A | 109.8 |
| C5—C6—H6 | 109.1 | C7A—C6A—H6A | 109.8 |
| C7—C6—H6 | 109.1 | C8A—C7A—C6A | 111.94 (11) |
| C8—C7—C11 | 117.26 (12) | C8A—C7A—C11A | 118.10 (12) |
| C8—C7—C6 | 112.75 (12) | C6A—C7A—C11A | 101.45 (11) |
| C11—C7—C6 | 101.19 (12) | C8A—C7A—H7A | 108.3 |
| C8—C7—H7 | 108.4 | C6A—C7A—H7A | 108.3 |
| C11—C7—H7 | 108.4 | C11A—C7A—H7A | 108.3 |
| C6—C7—H7 | 108.4 | O4A—C8A—C7A | 105.20 (11) |
| O4—C8—C7 | 106.51 (11) | O4A—C8A—C9A | 107.00 (11) |
| O4—C8—C9 | 107.23 (11) | C7A—C8A—C9A | 111.62 (12) |
| C7—C8—C9 | 111.92 (12) | O4A—C8A—H8A | 110.9 |
| O4—C8—H8 | 110.4 | C7A—C8A—H8A | 110.9 |
| C7—C8—H8 | 110.4 | C9A—C8A—H8A | 110.9 |
| C9—C8—H8 | 110.4 | C10A—C9A—C8A | 116.93 (12) |
| C10—C9—C8 | 114.89 (12) | C10A—C9A—H91A | 108.1 |
| C10—C9—H9A | 108.5 | C8A—C9A—H91A | 108.1 |
| C8—C9—H9A | 108.5 | C10A—C9A—H92A | 108.1 |
| C10—C9—H9B | 108.5 | C8A—C9A—H92A | 108.1 |
| C8—C9—H9B | 108.5 | H91A—C9A—H92A | 107.3 |
| H9A—C9—H9B | 107.5 | C1A—C10A—C14A | 123.41 (13) |
| C1—C10—C14 | 123.54 (14) | C1A—C10A—C9A | 123.36 (13) |
| C1—C10—C9 | 122.87 (13) | C14A—C10A—C9A | 113.23 (11) |
| C14—C10—C9 | 113.58 (12) | C13A—C11A—C12A | 112.04 (13) |
| C12—C11—C13 | 110.55 (15) | C13A—C11A—C7A | 117.99 (14) |
| C12—C11—C7 | 101.57 (12) | C12A—C11A—C7A | 101.17 (11) |
| C13—C11—C7 | 117.49 (16) | C13A—C11A—H11A | 108.4 |
| C12—C11—H11 | 108.9 | C12A—C11A—H11A | 108.4 |
| C13—C11—H11 | 108.9 | C7A—C11A—H11A | 108.4 |
| C7—C11—H11 | 108.9 | O2A—C12A—O1A | 121.52 (13) |
| O2—C12—O1 | 121.59 (14) | O2A—C12A—C11A | 128.52 (14) |
| O2—C12—C11 | 128.38 (15) | O1A—C12A—C11A | 109.96 (12) |
| O1—C12—C11 | 110.02 (13) | C11A—C13A—H13D | 109.5 |
| C11—C13—H13A | 109.5 | C11A—C13A—H13E | 109.5 |
| C11—C13—H13B | 109.5 | H13D—C13A—H13E | 109.5 |
| H13A—C13—H13B | 109.5 | C11A—C13A—H13F | 109.5 |
| C11—C13—H13C | 109.5 | H13D—C13A—H13F | 109.5 |
| H13A—C13—H13C | 109.5 | H13E—C13A—H13F | 109.5 |
| H13B—C13—H13C | 109.5 | C10A—C14A—H14D | 109.5 |
| C10—C14—H14A | 109.5 | C10A—C14A—H14E | 109.5 |
| C10—C14—H14B | 109.5 | H14D—C14A—H14E | 109.5 |
| H14A—C14—H14B | 109.5 | C10A—C14A—H14F | 109.5 |
| C10—C14—H14C | 109.5 | H14D—C14A—H14F | 109.5 |
| H14A—C14—H14C | 109.5 | H14E—C14A—H14F | 109.5 |
| H14B—C14—H14C | 109.5 | O6A—C15A—C4A | 112.23 (12) |
| O6—C15—C4 | 112.58 (12) | O6A—C15A—H15C | 109.2 |
| O6—C15—H15A | 109.1 | C4A—C15A—H15C | 109.2 |
| C4—C15—H15A | 109.1 | O6A—C15A—H15D | 109.2 |
| O6—C15—H15B | 109.1 | C4A—C15A—H15D | 109.2 |
| C4—C15—H15B | 109.1 | H15C—C15A—H15D | 107.9 |
| H15A—C15—H15B | 107.8 | O5A—C16A—O4A | 123.13 (14) |
| O5—C16—O4 | 123.69 (13) | O5A—C16A—C17A | 125.78 (14) |
| O5—C16—C17 | 125.11 (14) | O4A—C16A—C17A | 111.09 (13) |
| O4—C16—C17 | 111.18 (13) | C16A—C17A—H17D | 109.5 |
| C16—C17—H17A | 109.5 | C16A—C17A—H17E | 109.5 |
| C16—C17—H17B | 109.5 | H17D—C17A—H17E | 109.5 |
| H17A—C17—H17B | 109.5 | C16A—C17A—H17F | 109.5 |
| C16—C17—H17C | 109.5 | H17D—C17A—H17F | 109.5 |
| H17A—C17—H17C | 109.5 | H17E—C17A—H17F | 109.5 |
| H17B—C17—H17C | 109.5 | H72—O7—H71 | 106 (2) |
| C12A—O1A—C6A | 110.30 (10) | ||
| C10—C1—C2—O3 | 1.9 (3) | C10A—C1A—C2A—O3A | 11.1 (2) |
| C5—C1—C2—O3 | 179.40 (15) | C5A—C1A—C2A—O3A | −171.14 (15) |
| C10—C1—C2—C3 | −179.34 (14) | C10A—C1A—C2A—C3A | −171.77 (15) |
| C5—C1—C2—C3 | −1.83 (16) | C5A—C1A—C2A—C3A | 6.04 (16) |
| O3—C2—C3—C4 | −179.83 (14) | O3A—C2A—C3A—C4A | 174.67 (15) |
| C1—C2—C3—C4 | 1.35 (17) | C1A—C2A—C3A—C4A | −2.63 (18) |
| C2—C3—C4—C15 | −176.29 (14) | C2A—C3A—C4A—C15A | −178.68 (14) |
| C2—C3—C4—C5 | −0.30 (18) | C2A—C3A—C4A—C5A | −1.99 (18) |
| C3—C4—C5—C6 | 117.53 (15) | C3A—C4A—C5A—C6A | 127.48 (14) |
| C15—C4—C5—C6 | −66.36 (18) | C15A—C4A—C5A—C6A | −55.76 (19) |
| C3—C4—C5—C1 | −0.85 (16) | C3A—C4A—C5A—C1A | 5.58 (16) |
| C15—C4—C5—C1 | 175.27 (13) | C15A—C4A—C5A—C1A | −177.65 (13) |
| C10—C1—C5—C6 | 57.39 (19) | C10A—C1A—C5A—C6A | 47.5 (2) |
| C2—C1—C5—C6 | −120.12 (13) | C2A—C1A—C5A—C6A | −130.28 (12) |
| C10—C1—C5—C4 | 179.11 (15) | C10A—C1A—C5A—C4A | 170.90 (15) |
| C2—C1—C5—C4 | 1.60 (15) | C2A—C1A—C5A—C4A | −6.84 (15) |
| C12—O1—C6—C5 | 149.85 (14) | C12A—O1A—C6A—C5A | 146.40 (12) |
| C12—O1—C6—C7 | 26.24 (17) | C12A—O1A—C6A—C7A | 23.91 (15) |
| C4—C5—C6—O1 | 48.63 (17) | C4A—C5A—C6A—O1A | 52.01 (16) |
| C1—C5—C6—O1 | 163.25 (11) | C1A—C5A—C6A—O1A | 168.54 (11) |
| C4—C5—C6—C7 | 165.59 (12) | C4A—C5A—C6A—C7A | 167.24 (12) |
| C1—C5—C6—C7 | −79.78 (15) | C1A—C5A—C6A—C7A | −76.23 (15) |
| O1—C6—C7—C8 | −163.07 (12) | O1A—C6A—C7A—C8A | −162.59 (12) |
| C5—C6—C7—C8 | 75.57 (16) | C5A—C6A—C7A—C8A | 78.68 (16) |
| O1—C6—C7—C11 | −36.96 (15) | O1A—C6A—C7A—C11A | −35.75 (14) |
| C5—C6—C7—C11 | −158.32 (13) | C5A—C6A—C7A—C11A | −154.48 (12) |
| C16—O4—C8—C7 | −135.67 (13) | C16A—O4A—C8A—C7A | −158.28 (12) |
| C16—O4—C8—C9 | 104.36 (14) | C16A—O4A—C8A—C9A | 82.89 (15) |
| C11—C7—C8—O4 | 56.71 (17) | C6A—C7A—C8A—O4A | 172.54 (11) |
| C6—C7—C8—O4 | 173.63 (12) | C11A—C7A—C8A—O4A | 55.30 (16) |
| C11—C7—C8—C9 | 173.60 (13) | C6A—C7A—C8A—C9A | −71.77 (16) |
| C6—C7—C8—C9 | −69.48 (16) | C11A—C7A—C8A—C9A | 170.99 (13) |
| O4—C8—C9—C10 | −166.64 (12) | O4A—C8A—C9A—C10A | −170.91 (12) |
| C7—C8—C9—C10 | 76.91 (16) | C7A—C8A—C9A—C10A | 74.50 (16) |
| C2—C1—C10—C14 | −2.7 (2) | C2A—C1A—C10A—C14A | 4.0 (2) |
| C5—C1—C10—C14 | −179.77 (14) | C5A—C1A—C10A—C14A | −173.31 (14) |
| C2—C1—C10—C9 | 178.21 (14) | C2A—C1A—C10A—C9A | −175.04 (13) |
| C5—C1—C10—C9 | 1.2 (2) | C5A—C1A—C10A—C9A | 7.6 (2) |
| C8—C9—C10—C1 | −60.8 (2) | C8A—C9A—C10A—C1A | −59.5 (2) |
| C8—C9—C10—C14 | 120.02 (14) | C8A—C9A—C10A—C14A | 121.36 (14) |
| C8—C7—C11—C12 | 156.71 (14) | C8A—C7A—C11A—C13A | −80.60 (18) |
| C6—C7—C11—C12 | 33.66 (17) | C6A—C7A—C11A—C13A | 156.70 (14) |
| C8—C7—C11—C13 | −82.6 (2) | C8A—C7A—C11A—C12A | 156.85 (13) |
| C6—C7—C11—C13 | 154.36 (15) | C6A—C7A—C11A—C12A | 34.14 (15) |
| C6—O1—C12—O2 | 175.77 (18) | C6A—O1A—C12A—O2A | 179.11 (15) |
| C6—O1—C12—C11 | −4.1 (2) | C6A—O1A—C12A—C11A | −1.34 (17) |
| C13—C11—C12—O2 | 35.0 (3) | C13A—C11A—C12A—O2A | 31.4 (2) |
| C7—C11—C12—O2 | 160.5 (2) | C7A—C11A—C12A—O2A | 157.96 (17) |
| C13—C11—C12—O1 | −145.13 (17) | C13A—C11A—C12A—O1A | −148.13 (14) |
| C7—C11—C12—O1 | −19.7 (2) | C7A—C11A—C12A—O1A | −21.55 (16) |
| C3—C4—C15—O6 | 6.5 (2) | C3A—C4A—C15A—O6A | 12.0 (2) |
| C5—C4—C15—O6 | −169.07 (13) | C5A—C4A—C15A—O6A | −164.31 (13) |
| C8—O4—C16—O5 | −1.4 (2) | C8A—O4A—C16A—O5A | 2.9 (2) |
| C8—O4—C16—C17 | 177.21 (12) | C8A—O4A—C16A—C17A | −177.12 (12) |
| D—H···A | D—H | H···A | D···A | D—H···A |
| O6—H6O···O7 | 0.86 (2) | 1.85 (2) | 2.6750 (17) | 160 (2) |
| O6A—H60A···O6 | 0.85 (2) | 1.91 (2) | 2.7593 (17) | 174 (2) |
| O7—H72···O5Ai | 0.89 (2) | 1.95 (2) | 2.8160 (18) | 165 (2) |
| O7—H71···O6Aii | 0.89 (3) | 1.86 (3) | 2.7397 (18) | 176 (3) |
| Symmetry codes: (i) −x+1, y+1/2, −z+1; (ii) x, y+1, z. |
Experimental details
| Crystal data | |
| Chemical formula | C17H20O6·0.5H2O |
| Mr | 329.34 |
| Crystal system, space group | Monoclinic, P21 |
| Temperature (K) | 90 |
| a, b, c (Å) | 10.9276 (5), 7.4658 (5), 19.8571 (10) |
| β (°) | 100.850 (5) |
| V (Å3) | 1591.05 (15) |
| Z | 4 |
| Radiation type | Cu Kα |
| µ (mm−1) | 0.88 |
| Crystal size (mm) | 0.27 × 0.17 × 0.10 |
| Data collection | |
| Diffractometer | Bruker Kappa APEXII CCD area-detector diffractometer |
| Absorption correction | Multi-scan (SADABS; Sheldrick, 2004) |
| Tmin, Tmax | 0.796, 0.917 |
| No. of measured, independent and observed [I > 2σ(I)] reflections | 23565, 5642, 5513 |
| Rint | 0.031 |
| (sin θ/λ)max (Å−1) | 0.606 |
| Refinement | |
| R[F2 > 2σ(F2)], wR(F2), S | 0.027, 0.068, 1.03 |
| No. of reflections | 5642 |
| No. of parameters | 445 |
| No. of restraints | 1 |
| H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
| Δρmax, Δρmin (e Å−3) | 0.20, −0.14 |
| Absolute structure | Flack (1983), 2516 Friedel pairs |
| Absolute structure parameter | −0.01 (10) |
Computer programs: APEX2 (Bruker, 2006), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997), SHELXTL (Sheldrick, 2008).
| D—H···A | D—H | H···A | D···A | D—H···A |
| O6—H6O···O7 | 0.86 (2) | 1.85 (2) | 2.6750 (17) | 160 (2) |
| O6A—H60A···O6 | 0.85 (2) | 1.91 (2) | 2.7593 (17) | 174 (2) |
| O7—H72···O5Ai | 0.89 (2) | 1.95 (2) | 2.8160 (18) | 165 (2) |
| O7—H71···O6Aii | 0.89 (3) | 1.86 (3) | 2.7397 (18) | 176 (3) |
| Symmetry codes: (i) −x+1, y+1/2, −z+1; (ii) x, y+1, z. |


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,13-Dihydrolactucin-8-

Alert level B
Alert level C
Alert level G
![[Figure 1]](http://journals.iucr.org/e/issues/2009/10/00/pv2210/pv2210fig1thm.gif)




Hairy root cultures of blue-flowered lettice, Lactuca floridana, tribe Lactuceae (Asteraceae) are useful for the study of the biosynthesis of guaianolide-type sesquiterpene lactones (Song et al., 1995). The title guaianolide was isolated from L. floridana and crystallized as the hemihydrate.
The structures of both independent molecules are shown in Fig. 1. The conformations of (1) and (1 A) are very similar. Both seven-membered rings form chair conformations where atoms C5/C6/C8/C9 are nearly coplanar (maximum deviation 0.022 (1) Å for molecule 1 and 0.024 (1) Å for 1 A). Atom C1 is 0.991 (1) Å above the plane, C7 is 0.751 (1) Å below, and C10 is 1.029 (1) Å above. Atom C1A is 0.881 (1) Å above the plane, C7A is 0.773 (1) Å below, and C10A is 0.965 (1) Å above. Lactone ring (C6/C7/C11/C12/O1) has the C7 envelope conformation, with C7 0.582 (1) Å out of the best plane of the other four (maximum deviation 0.022 (1) Å. Lactone ring (C6A/C7A/C11A/C12A/O1A) also has the C7 envelope conformation, with C7A showing deviation 0.580 (1) Å, and maximum deviation 0.007 (1) Å for the other four. The other 5-membered rings (C1—C5 and C1a—C5A,) are essentially planar (maximum deviations 0.011 (1) Å and 0.041 (1) Å, respectively). This conformation is similar to that seen in matricarin (Parvez et al., 2002), which differs only by lacking the OH group at C15.
Hydrogen bonding involves the OH groups, the water molecule, and the acetate CO group, and forms double-strand chains along [0 1 0]. In each chain, the alternation of hydrogen bonds is (O6A—H···O6—H···H2O···)n.
The absolute configuration was determined by refinement of the Flack (1983) parameter, based on resonant scattering of the light atoms. It agrees with that of lactucin (Ruban et al., 1978) and with the accepted configuration of sesquiterpene lactones from higher plants (Fischer et al., 1979). Analysis of the Bijvoet pairs using the method of Hooft et al. (2008) yielded y = 0.03 (4) for this structure, confirming the absolute configuration.