organic compounds
Isotenulin
aDepartment of Chemistry, The University of Tennessee at Chattanooga, Chattanooga, TN 37403, USA
*Correspondence e-mail: kyle-knight@utc.edu
Isotenulin, C17H22O5, is a sesquiterpene lactone isolated from sneezeweed Helenium amarum. It crystallizes with two independent molecules in the In each molecule, two five-membered rings (cyclopentenone and lactone) are trans-fused to the central seven-membered ring. The five-membered rings each adopt envelope conformations. The seven-membered ring adopts a twist-chair conformation. In the crystal, the molecules are linked by C—H⋯O interactions, which generate a three-dimensional network.
Related literature
For the discovery and structural identification of tenulin, see: Clark (1939); Herz et al. (1975); Braun et al. (1956); Barton et al. (1956). For biological activity that has been observed for tenulin and its analogs, see: Lee et al. (1977); Li et al. (2008); Hodge et al. (1995, and references therein). For the of tenulin, see: Knight et al. (2013). For the of bromoisotenulin, see: Mazhar-Ul-Haque et al. (1974).
Experimental
Crystal data
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Data collection: APEX2 (Bruker, 2009); cell SAINT (Bruker, 2009); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: OLEX2.
Supporting information
10.1107/S1600536813019703/cv5424sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536813019703/cv5424Isup2.hkl
Supporting information file. DOI: 10.1107/S1600536813019703/cv5424Isup3.cdx
H atoms were positioned geometrically at bond distances of 0.98, 0.99, 1.00 and 0.95 Å for methyl, methylene, methine and vinyl, respectively, and constrained to ride on their parent atoms with Uiso(H)= 1.2–1.5 Ueq(C).
Data collection: APEX2 (Bruker, 2009); cell
SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009).Fig. 1. Two independent molecules of isotenulin with the atomic numbering and displacement ellipsoids drawn at the 50% probability level. |
C17H22O5 | Dx = 1.277 Mg m−3 |
Mr = 306.34 | Mo Kα radiation, λ = 0.71073 Å |
Orthorhombic, P212121 | Cell parameters from 9402 reflections |
a = 6.4565 (11) Å | θ = 2.3–23.8° |
b = 17.625 (3) Å | µ = 0.09 mm−1 |
c = 27.997 (4) Å | T = 200 K |
V = 3186.0 (9) Å3 | Block, colourless |
Z = 8 | 0.55 × 0.3 × 0.2 mm |
F(000) = 1312 |
Bruker APEXII CCD diffractometer | Rint = 0.047 |
Graphite monochromator | θmax = 25.1°, θmin = 2.3° |
ϕ and ω scans | h = −7→7 |
34729 measured reflections | k = −21→20 |
5611 independent reflections | l = −31→31 |
4883 reflections with I > 2σ(I) |
Refinement on F2 | 0 restraints |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.043 | H-atom parameters constrained |
wR(F2) = 0.100 | w = 1/[σ2(Fo2) + (0.0573P)2 + 0.5452P] where P = (Fo2 + 2Fc2)/3 |
S = 1.01 | (Δ/σ)max < 0.001 |
5611 reflections | Δρmax = 0.13 e Å−3 |
405 parameters | Δρmin = −0.17 e Å−3 |
C17H22O5 | V = 3186.0 (9) Å3 |
Mr = 306.34 | Z = 8 |
Orthorhombic, P212121 | Mo Kα radiation |
a = 6.4565 (11) Å | µ = 0.09 mm−1 |
b = 17.625 (3) Å | T = 200 K |
c = 27.997 (4) Å | 0.55 × 0.3 × 0.2 mm |
Bruker APEXII CCD diffractometer | 4883 reflections with I > 2σ(I) |
34729 measured reflections | Rint = 0.047 |
5611 independent reflections |
R[F2 > 2σ(F2)] = 0.043 | 0 restraints |
wR(F2) = 0.100 | H-atom parameters constrained |
S = 1.01 | Δρmax = 0.13 e Å−3 |
5611 reflections | Δρmin = −0.17 e Å−3 |
405 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
O1 | 0.6652 (3) | 0.32092 (12) | 0.13792 (7) | 0.0282 (5) | |
O4 | 0.4353 (4) | 0.20905 (15) | −0.02363 (8) | 0.0460 (6) | |
O2 | 0.4385 (4) | 0.33063 (13) | −0.00295 (7) | 0.0384 (6) | |
O5 | 0.4353 (5) | 0.39087 (15) | 0.23006 (8) | 0.0521 (7) | |
O3 | 0.5852 (4) | 0.21748 (14) | 0.18164 (8) | 0.0437 (6) | |
O10 | 0.8514 (4) | 0.91154 (14) | 0.06402 (9) | 0.0426 (6) | |
O9 | 0.0773 (4) | 0.66834 (13) | 0.21828 (9) | 0.0470 (6) | |
O8 | 0.8155 (5) | 0.72399 (18) | 0.09136 (11) | 0.0705 (9) | |
O6 | 0.5119 (3) | 0.78613 (12) | 0.08363 (7) | 0.0322 (5) | |
O7 | 0.0566 (3) | 0.78753 (12) | 0.19284 (8) | 0.0342 (5) | |
C17 | 0.1123 (6) | 0.5589 (2) | 0.05783 (14) | 0.0489 (10) | |
H17A | 0.1440 | 0.5799 | 0.0263 | 0.073* | |
H17B | 0.1065 | 0.6000 | 0.0813 | 0.073* | |
H17C | −0.0218 | 0.5329 | 0.0567 | 0.073* | |
C14 | 0.2811 (5) | 0.50237 (18) | 0.07211 (11) | 0.0333 (8) | |
H14 | 0.4150 | 0.5305 | 0.0750 | 0.040* | |
C13 | 0.2347 (5) | 0.46402 (17) | 0.12044 (10) | 0.0267 (7) | |
H13 | 0.1279 | 0.4241 | 0.1142 | 0.032* | |
C9 | 0.4208 (5) | 0.42363 (16) | 0.14536 (10) | 0.0256 (7) | |
C3 | 0.4490 (5) | 0.33964 (16) | 0.13131 (10) | 0.0241 (6) | |
H3 | 0.3655 | 0.3079 | 0.1538 | 0.029* | |
C2 | 0.7118 (5) | 0.26042 (19) | 0.16595 (12) | 0.0331 (7) | |
C8 | 0.9396 (6) | 0.2557 (2) | 0.17373 (14) | 0.0541 (10) | |
H8A | 0.9851 | 0.2990 | 0.1930 | 0.081* | |
H8B | 1.0108 | 0.2566 | 0.1428 | 0.081* | |
H8C | 0.9728 | 0.2084 | 0.1905 | 0.081* | |
C6 | 0.4421 (5) | 0.2565 (2) | 0.00761 (12) | 0.0355 (8) | |
C5 | 0.4467 (5) | 0.37680 (18) | 0.04092 (10) | 0.0316 (7) | |
H5 | 0.5910 | 0.3951 | 0.0468 | 0.038* | |
C15 | 0.3031 (5) | 0.44332 (19) | 0.03186 (11) | 0.0355 (8) | |
H15A | 0.1636 | 0.4229 | 0.0247 | 0.043* | |
H15B | 0.3520 | 0.4700 | 0.0028 | 0.043* | |
C12 | 0.1511 (5) | 0.51352 (18) | 0.16020 (12) | 0.0329 (7) | |
H12 | 0.0591 | 0.5547 | 0.1549 | 0.040* | |
C11 | 0.2185 (5) | 0.49380 (19) | 0.20298 (12) | 0.0363 (8) | |
H11 | 0.1781 | 0.5170 | 0.2322 | 0.044* | |
C10 | 0.3644 (5) | 0.43101 (18) | 0.19861 (11) | 0.0327 (7) | |
C4 | 0.3809 (4) | 0.32060 (16) | 0.08008 (10) | 0.0253 (6) | |
H4 | 0.2260 | 0.3190 | 0.0800 | 0.030* | |
C1 | 0.4563 (5) | 0.24438 (18) | 0.06090 (11) | 0.0324 (7) | |
H1 | 0.6058 | 0.2388 | 0.0695 | 0.039* | |
C7 | 0.3428 (6) | 0.17418 (18) | 0.07783 (12) | 0.0435 (9) | |
H7A | 0.1950 | 0.1791 | 0.0706 | 0.065* | |
H7B | 0.3613 | 0.1685 | 0.1124 | 0.065* | |
H7C | 0.3987 | 0.1295 | 0.0615 | 0.065* | |
C16 | 0.6230 (5) | 0.46954 (18) | 0.14028 (13) | 0.0364 (8) | |
H16A | 0.5950 | 0.5232 | 0.1468 | 0.055* | |
H16B | 0.6765 | 0.4641 | 0.1077 | 0.055* | |
H16C | 0.7258 | 0.4505 | 0.1631 | 0.055* | |
C27 | 0.7412 (5) | 0.94561 (18) | 0.09205 (11) | 0.0300 (7) | |
C26 | 0.5369 (4) | 0.91551 (16) | 0.11260 (10) | 0.0241 (6) | |
C20 | 0.5510 (5) | 0.83112 (16) | 0.12654 (9) | 0.0247 (6) | |
H20 | 0.6953 | 0.8205 | 0.1377 | 0.030* | |
C21 | 0.4003 (4) | 0.80785 (16) | 0.16622 (10) | 0.0245 (6) | |
H21 | 0.4636 | 0.8252 | 0.1969 | 0.029* | |
C18 | 0.3614 (5) | 0.72245 (17) | 0.17173 (11) | 0.0306 (7) | |
H18 | 0.3445 | 0.6999 | 0.1392 | 0.037* | |
C23 | 0.1542 (5) | 0.72034 (18) | 0.19676 (12) | 0.0344 (8) | |
C19 | 0.6589 (6) | 0.7361 (2) | 0.06999 (13) | 0.0448 (9) | |
C33 | 0.3809 (5) | 0.93110 (19) | 0.07173 (10) | 0.0317 (7) | |
H33A | 0.3752 | 0.9857 | 0.0653 | 0.048* | |
H33B | 0.2432 | 0.9131 | 0.0812 | 0.048* | |
H33C | 0.4255 | 0.9043 | 0.0428 | 0.048* | |
C28 | 0.7730 (5) | 1.02207 (18) | 0.11142 (12) | 0.0351 (8) | |
H28 | 0.8739 | 1.0573 | 0.1005 | 0.042* | |
C29 | 0.6391 (5) | 1.03451 (17) | 0.14657 (12) | 0.0329 (7) | |
H29 | 0.6320 | 1.0810 | 0.1636 | 0.039* | |
C30 | 0.4996 (4) | 0.96816 (16) | 0.15690 (10) | 0.0256 (7) | |
H30 | 0.5592 | 0.9414 | 0.1852 | 0.031* | |
C31 | 0.2724 (5) | 0.98620 (17) | 0.16899 (11) | 0.0290 (7) | |
H31 | 0.2009 | 1.0018 | 0.1389 | 0.035* | |
C32 | 0.1562 (5) | 0.91723 (17) | 0.18982 (11) | 0.0294 (7) | |
H32A | 0.2012 | 0.9109 | 0.2234 | 0.035* | |
H32B | 0.0067 | 0.9297 | 0.1904 | 0.035* | |
C22 | 0.1807 (5) | 0.84120 (17) | 0.16491 (11) | 0.0277 (7) | |
H22 | 0.1287 | 0.8441 | 0.1313 | 0.033* | |
C24 | 0.5304 (6) | 0.67908 (19) | 0.19779 (13) | 0.0439 (9) | |
H24A | 0.5580 | 0.7034 | 0.2286 | 0.066* | |
H24B | 0.6571 | 0.6792 | 0.1785 | 0.066* | |
H24C | 0.4853 | 0.6267 | 0.2031 | 0.066* | |
C34 | 0.2531 (6) | 1.05118 (18) | 0.20498 (13) | 0.0431 (9) | |
H34A | 0.3292 | 1.0382 | 0.2341 | 0.065* | |
H34B | 0.1067 | 1.0593 | 0.2127 | 0.065* | |
H34C | 0.3110 | 1.0976 | 0.1911 | 0.065* | |
C25 | 0.5960 (8) | 0.6984 (2) | 0.02392 (14) | 0.0628 (12) | |
H25A | 0.6992 | 0.6600 | 0.0153 | 0.094* | |
H25B | 0.5874 | 0.7365 | −0.0015 | 0.094* | |
H25C | 0.4606 | 0.6741 | 0.0280 | 0.094* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0238 (10) | 0.0339 (11) | 0.0271 (11) | 0.0024 (9) | 0.0006 (9) | 0.0045 (10) |
O4 | 0.0406 (14) | 0.0598 (16) | 0.0378 (13) | 0.0078 (13) | 0.0003 (12) | −0.0218 (12) |
O2 | 0.0446 (14) | 0.0484 (15) | 0.0224 (11) | 0.0033 (12) | 0.0045 (10) | −0.0046 (10) |
O5 | 0.0764 (19) | 0.0547 (15) | 0.0253 (12) | 0.0087 (15) | −0.0102 (13) | −0.0023 (12) |
O3 | 0.0402 (14) | 0.0408 (13) | 0.0500 (15) | −0.0044 (12) | −0.0046 (12) | 0.0171 (11) |
O10 | 0.0275 (12) | 0.0566 (16) | 0.0438 (14) | 0.0042 (11) | 0.0089 (11) | 0.0024 (12) |
O9 | 0.0493 (15) | 0.0327 (13) | 0.0590 (15) | −0.0097 (12) | 0.0163 (13) | 0.0010 (12) |
O8 | 0.063 (2) | 0.086 (2) | 0.0628 (19) | 0.0438 (17) | −0.0031 (16) | −0.0259 (17) |
O6 | 0.0304 (12) | 0.0382 (12) | 0.0280 (11) | 0.0024 (9) | 0.0029 (9) | −0.0120 (10) |
O7 | 0.0278 (11) | 0.0319 (12) | 0.0429 (13) | −0.0028 (10) | 0.0088 (10) | −0.0016 (10) |
C17 | 0.059 (2) | 0.044 (2) | 0.044 (2) | 0.0129 (19) | −0.0084 (19) | 0.0053 (17) |
C14 | 0.0392 (18) | 0.0320 (16) | 0.0285 (18) | −0.0013 (14) | −0.0037 (14) | 0.0026 (14) |
C13 | 0.0236 (15) | 0.0277 (16) | 0.0288 (17) | −0.0016 (13) | −0.0004 (13) | −0.0022 (13) |
C9 | 0.0238 (15) | 0.0302 (15) | 0.0228 (15) | −0.0024 (13) | −0.0026 (13) | −0.0015 (13) |
C3 | 0.0186 (14) | 0.0303 (16) | 0.0234 (15) | −0.0026 (12) | 0.0013 (12) | 0.0022 (12) |
C2 | 0.0357 (18) | 0.0369 (18) | 0.0267 (16) | 0.0038 (15) | 0.0011 (15) | 0.0015 (15) |
C8 | 0.035 (2) | 0.070 (3) | 0.057 (2) | 0.016 (2) | −0.0001 (18) | 0.019 (2) |
C6 | 0.0241 (16) | 0.048 (2) | 0.0341 (18) | 0.0061 (16) | 0.0003 (14) | −0.0122 (17) |
C5 | 0.0324 (16) | 0.0404 (18) | 0.0220 (15) | −0.0027 (15) | 0.0017 (14) | −0.0022 (14) |
C15 | 0.042 (2) | 0.0411 (19) | 0.0234 (17) | −0.0022 (16) | −0.0004 (14) | 0.0082 (14) |
C12 | 0.0257 (15) | 0.0316 (16) | 0.042 (2) | −0.0012 (14) | 0.0022 (15) | −0.0049 (15) |
C11 | 0.0374 (19) | 0.0398 (19) | 0.0318 (19) | −0.0045 (16) | 0.0051 (15) | −0.0116 (15) |
C10 | 0.0355 (18) | 0.0369 (18) | 0.0256 (17) | −0.0076 (15) | −0.0063 (15) | −0.0037 (15) |
C4 | 0.0198 (14) | 0.0303 (16) | 0.0259 (15) | −0.0009 (12) | 0.0001 (12) | −0.0010 (13) |
C1 | 0.0292 (16) | 0.0366 (17) | 0.0314 (16) | 0.0091 (15) | −0.0046 (14) | −0.0071 (14) |
C7 | 0.058 (2) | 0.0315 (18) | 0.041 (2) | 0.0013 (17) | −0.0110 (18) | −0.0045 (16) |
C16 | 0.0296 (17) | 0.0351 (17) | 0.044 (2) | −0.0045 (15) | −0.0028 (16) | −0.0010 (16) |
C27 | 0.0206 (15) | 0.0419 (18) | 0.0275 (17) | 0.0050 (14) | −0.0042 (14) | 0.0056 (15) |
C26 | 0.0170 (14) | 0.0342 (17) | 0.0210 (15) | 0.0031 (13) | −0.0050 (12) | −0.0019 (13) |
C20 | 0.0189 (14) | 0.0304 (16) | 0.0247 (15) | 0.0025 (13) | −0.0031 (12) | −0.0071 (13) |
C21 | 0.0256 (15) | 0.0258 (14) | 0.0221 (15) | −0.0002 (12) | −0.0017 (13) | −0.0049 (12) |
C18 | 0.0335 (17) | 0.0277 (15) | 0.0306 (17) | −0.0016 (14) | 0.0029 (14) | −0.0059 (14) |
C23 | 0.0380 (18) | 0.0299 (17) | 0.0353 (18) | −0.0071 (16) | 0.0027 (16) | −0.0099 (15) |
C19 | 0.050 (2) | 0.043 (2) | 0.041 (2) | 0.0078 (18) | 0.0134 (19) | −0.0092 (17) |
C33 | 0.0275 (16) | 0.0452 (19) | 0.0224 (17) | 0.0022 (14) | −0.0025 (13) | −0.0002 (14) |
C28 | 0.0246 (16) | 0.0370 (18) | 0.0436 (19) | −0.0042 (14) | −0.0036 (15) | 0.0138 (16) |
C29 | 0.0300 (16) | 0.0282 (16) | 0.0405 (19) | 0.0006 (14) | −0.0107 (15) | 0.0021 (14) |
C30 | 0.0282 (16) | 0.0245 (15) | 0.0241 (16) | 0.0030 (12) | −0.0053 (12) | 0.0001 (12) |
C31 | 0.0299 (16) | 0.0312 (16) | 0.0259 (16) | 0.0050 (13) | 0.0015 (14) | 0.0007 (14) |
C32 | 0.0253 (15) | 0.0330 (16) | 0.0299 (17) | 0.0064 (13) | 0.0041 (14) | −0.0017 (13) |
C22 | 0.0256 (16) | 0.0320 (16) | 0.0256 (15) | −0.0030 (13) | 0.0027 (13) | 0.0008 (13) |
C24 | 0.041 (2) | 0.0335 (18) | 0.057 (2) | 0.0031 (17) | 0.0045 (18) | 0.0076 (18) |
C34 | 0.057 (2) | 0.0284 (17) | 0.044 (2) | 0.0022 (17) | 0.0137 (18) | −0.0048 (16) |
C25 | 0.076 (3) | 0.062 (3) | 0.051 (2) | 0.003 (2) | 0.015 (2) | −0.030 (2) |
O1—C3 | 1.446 (3) | C1—C7 | 1.514 (5) |
O1—C2 | 1.358 (4) | C7—H7A | 0.9800 |
O4—C6 | 1.211 (4) | C7—H7B | 0.9800 |
O2—C6 | 1.340 (4) | C7—H7C | 0.9800 |
O2—C5 | 1.474 (4) | C16—H16A | 0.9800 |
O5—C10 | 1.219 (4) | C16—H16B | 0.9800 |
O3—C2 | 1.198 (4) | C16—H16C | 0.9800 |
O10—C27 | 1.218 (4) | C27—C26 | 1.533 (4) |
O9—C23 | 1.204 (4) | C27—C28 | 1.467 (5) |
O8—C19 | 1.194 (5) | C26—C20 | 1.540 (4) |
O6—C20 | 1.462 (3) | C26—C33 | 1.549 (4) |
O6—C19 | 1.350 (4) | C26—C30 | 1.568 (4) |
O7—C23 | 1.346 (4) | C20—H20 | 1.0000 |
O7—C22 | 1.466 (4) | C20—C21 | 1.533 (4) |
C17—H17A | 0.9800 | C21—H21 | 1.0000 |
C17—H17B | 0.9800 | C21—C18 | 1.534 (4) |
C17—H17C | 0.9800 | C21—C22 | 1.535 (4) |
C17—C14 | 1.530 (5) | C18—H18 | 1.0000 |
C14—H14 | 1.0000 | C18—C23 | 1.511 (5) |
C14—C13 | 1.542 (4) | C18—C24 | 1.519 (5) |
C14—C15 | 1.540 (5) | C19—C25 | 1.507 (5) |
C13—H13 | 1.0000 | C33—H33A | 0.9800 |
C13—C9 | 1.561 (4) | C33—H33B | 0.9800 |
C13—C12 | 1.514 (4) | C33—H33C | 0.9800 |
C9—C3 | 1.542 (4) | C28—H28 | 0.9500 |
C9—C10 | 1.540 (4) | C28—C29 | 1.328 (5) |
C9—C16 | 1.542 (4) | C29—H29 | 0.9500 |
C3—H3 | 1.0000 | C29—C30 | 1.504 (4) |
C3—C4 | 1.537 (4) | C30—H30 | 1.0000 |
C2—C8 | 1.489 (5) | C30—C31 | 1.539 (4) |
C8—H8A | 0.9800 | C31—H31 | 1.0000 |
C8—H8B | 0.9800 | C31—C32 | 1.543 (4) |
C8—H8C | 0.9800 | C31—C34 | 1.530 (4) |
C6—C1 | 1.510 (5) | C32—H32A | 0.9900 |
C5—H5 | 1.0000 | C32—H32B | 0.9900 |
C5—C15 | 1.516 (5) | C32—C22 | 1.519 (4) |
C5—C4 | 1.537 (4) | C22—H22 | 1.0000 |
C15—H15A | 0.9900 | C24—H24A | 0.9800 |
C15—H15B | 0.9900 | C24—H24B | 0.9800 |
C12—H12 | 0.9500 | C24—H24C | 0.9800 |
C12—C11 | 1.321 (5) | C34—H34A | 0.9800 |
C11—H11 | 0.9500 | C34—H34B | 0.9800 |
C11—C10 | 1.459 (5) | C34—H34C | 0.9800 |
C4—H4 | 1.0000 | C25—H25A | 0.9800 |
C4—C1 | 1.526 (4) | C25—H25B | 0.9800 |
C1—H1 | 1.0000 | C25—H25C | 0.9800 |
C2—O1—C3 | 117.8 (2) | H16A—C16—H16C | 109.5 |
C6—O2—C5 | 110.7 (2) | H16B—C16—H16C | 109.5 |
C19—O6—C20 | 117.7 (3) | O10—C27—C26 | 125.0 (3) |
C23—O7—C22 | 110.8 (2) | O10—C27—C28 | 127.6 (3) |
H17A—C17—H17B | 109.5 | C28—C27—C26 | 107.4 (3) |
H17A—C17—H17C | 109.5 | C27—C26—C20 | 112.2 (2) |
H17B—C17—H17C | 109.5 | C27—C26—C33 | 102.8 (2) |
C14—C17—H17A | 109.5 | C27—C26—C30 | 103.0 (2) |
C14—C17—H17B | 109.5 | C20—C26—C33 | 113.4 (2) |
C14—C17—H17C | 109.5 | C20—C26—C30 | 112.3 (2) |
C17—C14—H14 | 108.3 | C33—C26—C30 | 112.3 (2) |
C17—C14—C13 | 112.1 (3) | O6—C20—C26 | 107.8 (2) |
C17—C14—C15 | 108.3 (3) | O6—C20—H20 | 108.4 |
C13—C14—H14 | 108.3 | O6—C20—C21 | 109.9 (2) |
C15—C14—H14 | 108.3 | C26—C20—H20 | 108.4 |
C15—C14—C13 | 111.3 (3) | C21—C20—C26 | 113.9 (2) |
C14—C13—H13 | 106.8 | C21—C20—H20 | 108.4 |
C14—C13—C9 | 116.3 (3) | C20—C21—H21 | 106.3 |
C9—C13—H13 | 106.8 | C20—C21—C18 | 116.1 (2) |
C12—C13—C14 | 117.5 (3) | C20—C21—C22 | 117.8 (2) |
C12—C13—H13 | 106.8 | C18—C21—H21 | 106.3 |
C12—C13—C9 | 102.0 (2) | C18—C21—C22 | 103.1 (2) |
C3—C9—C13 | 114.5 (2) | C22—C21—H21 | 106.3 |
C10—C9—C13 | 102.3 (2) | C21—C18—H18 | 108.4 |
C10—C9—C3 | 110.8 (2) | C23—C18—C21 | 102.5 (2) |
C10—C9—C16 | 104.2 (2) | C23—C18—H18 | 108.4 |
C16—C9—C13 | 111.8 (2) | C23—C18—C24 | 113.6 (3) |
C16—C9—C3 | 112.3 (2) | C24—C18—C21 | 115.1 (3) |
O1—C3—C9 | 107.5 (2) | C24—C18—H18 | 108.4 |
O1—C3—H3 | 108.2 | O9—C23—O7 | 121.2 (3) |
O1—C3—C4 | 110.2 (2) | O9—C23—C18 | 128.0 (3) |
C9—C3—H3 | 108.2 | O7—C23—C18 | 110.8 (3) |
C4—C3—C9 | 114.4 (2) | O8—C19—O6 | 124.8 (3) |
C4—C3—H3 | 108.2 | O8—C19—C25 | 125.3 (3) |
O1—C2—C8 | 110.3 (3) | O6—C19—C25 | 109.9 (4) |
O3—C2—O1 | 123.8 (3) | C26—C33—H33A | 109.5 |
O3—C2—C8 | 125.8 (3) | C26—C33—H33B | 109.5 |
C2—C8—H8A | 109.5 | C26—C33—H33C | 109.5 |
C2—C8—H8B | 109.5 | H33A—C33—H33B | 109.5 |
C2—C8—H8C | 109.5 | H33A—C33—H33C | 109.5 |
H8A—C8—H8B | 109.5 | H33B—C33—H33C | 109.5 |
H8A—C8—H8C | 109.5 | C27—C28—H28 | 125.2 |
H8B—C8—H8C | 109.5 | C29—C28—C27 | 109.5 (3) |
O4—C6—O2 | 120.9 (3) | C29—C28—H28 | 125.2 |
O4—C6—C1 | 128.2 (3) | C28—C29—H29 | 123.1 |
O2—C6—C1 | 110.9 (3) | C28—C29—C30 | 113.8 (3) |
O2—C5—H5 | 110.4 | C30—C29—H29 | 123.1 |
O2—C5—C15 | 105.4 (2) | C26—C30—H30 | 106.8 |
O2—C5—C4 | 103.2 (2) | C29—C30—C26 | 102.5 (2) |
C15—C5—H5 | 110.4 | C29—C30—H30 | 106.8 |
C15—C5—C4 | 116.7 (3) | C29—C30—C31 | 116.9 (2) |
C4—C5—H5 | 110.4 | C31—C30—C26 | 116.3 (2) |
C14—C15—H15A | 108.0 | C31—C30—H30 | 106.8 |
C14—C15—H15B | 108.0 | C30—C31—H31 | 108.1 |
C5—C15—C14 | 117.2 (3) | C30—C31—C32 | 112.6 (2) |
C5—C15—H15A | 108.0 | C32—C31—H31 | 108.1 |
C5—C15—H15B | 108.0 | C34—C31—C30 | 112.1 (3) |
H15A—C15—H15B | 107.2 | C34—C31—H31 | 108.1 |
C13—C12—H12 | 123.3 | C34—C31—C32 | 107.5 (3) |
C11—C12—C13 | 113.4 (3) | C31—C32—H32A | 107.8 |
C11—C12—H12 | 123.3 | C31—C32—H32B | 107.8 |
C12—C11—H11 | 125.2 | H32A—C32—H32B | 107.1 |
C12—C11—C10 | 109.7 (3) | C22—C32—C31 | 118.1 (2) |
C10—C11—H11 | 125.2 | C22—C32—H32A | 107.8 |
O5—C10—C9 | 124.2 (3) | C22—C32—H32B | 107.8 |
O5—C10—C11 | 128.5 (3) | O7—C22—C21 | 104.2 (2) |
C11—C10—C9 | 107.3 (3) | O7—C22—C32 | 105.5 (2) |
C3—C4—C5 | 116.5 (2) | O7—C22—H22 | 110.6 |
C3—C4—H4 | 107.1 | C21—C22—H22 | 110.6 |
C5—C4—H4 | 107.1 | C32—C22—C21 | 115.0 (3) |
C1—C4—C3 | 115.4 (2) | C32—C22—H22 | 110.6 |
C1—C4—C5 | 103.2 (2) | C18—C24—H24A | 109.5 |
C1—C4—H4 | 107.1 | C18—C24—H24B | 109.5 |
C6—C1—C4 | 101.8 (2) | C18—C24—H24C | 109.5 |
C6—C1—H1 | 108.1 | H24A—C24—H24B | 109.5 |
C6—C1—C7 | 113.3 (3) | H24A—C24—H24C | 109.5 |
C4—C1—H1 | 108.1 | H24B—C24—H24C | 109.5 |
C7—C1—C4 | 117.0 (3) | C31—C34—H34A | 109.5 |
C7—C1—H1 | 108.1 | C31—C34—H34B | 109.5 |
C1—C7—H7A | 109.5 | C31—C34—H34C | 109.5 |
C1—C7—H7B | 109.5 | H34A—C34—H34B | 109.5 |
C1—C7—H7C | 109.5 | H34A—C34—H34C | 109.5 |
H7A—C7—H7B | 109.5 | H34B—C34—H34C | 109.5 |
H7A—C7—H7C | 109.5 | C19—C25—H25A | 109.5 |
H7B—C7—H7C | 109.5 | C19—C25—H25B | 109.5 |
C9—C16—H16A | 109.5 | C19—C25—H25C | 109.5 |
C9—C16—H16B | 109.5 | H25A—C25—H25B | 109.5 |
C9—C16—H16C | 109.5 | H25A—C25—H25C | 109.5 |
H16A—C16—H16B | 109.5 | H25B—C25—H25C | 109.5 |
O1—C3—C4—C5 | −77.5 (3) | C10—C9—C3—C4 | 146.2 (3) |
O1—C3—C4—C1 | 43.8 (3) | C4—C5—C15—C14 | 66.5 (4) |
O4—C6—C1—C4 | −160.3 (3) | C16—C9—C3—O1 | 25.0 (3) |
O4—C6—C1—C7 | −33.7 (5) | C16—C9—C3—C4 | −97.7 (3) |
O2—C6—C1—C4 | 20.1 (3) | C16—C9—C10—O5 | −84.0 (4) |
O2—C6—C1—C7 | 146.6 (3) | C16—C9—C10—C11 | 95.2 (3) |
O2—C5—C15—C14 | −179.7 (3) | C27—C26—C20—O6 | −84.3 (3) |
O2—C5—C4—C3 | 157.7 (2) | C27—C26—C20—C21 | 153.5 (2) |
O2—C5—C4—C1 | 30.2 (3) | C27—C26—C30—C29 | 18.1 (3) |
O10—C27—C26—C20 | 41.9 (4) | C27—C26—C30—C31 | 146.9 (3) |
O10—C27—C26—C33 | −80.3 (3) | C27—C28—C29—C30 | 1.1 (4) |
O10—C27—C26—C30 | 162.9 (3) | C26—C27—C28—C29 | 11.6 (3) |
O10—C27—C28—C29 | −169.9 (3) | C26—C20—C21—C18 | 163.0 (2) |
O6—C20—C21—C18 | 42.0 (3) | C26—C20—C21—C22 | 40.0 (3) |
O6—C20—C21—C22 | −81.0 (3) | C26—C30—C31—C32 | 71.5 (3) |
C17—C14—C13—C9 | −163.2 (3) | C26—C30—C31—C34 | −167.1 (3) |
C17—C14—C13—C12 | −42.0 (4) | C20—O6—C19—O8 | 2.8 (5) |
C17—C14—C15—C5 | −173.7 (3) | C20—O6—C19—C25 | −177.0 (3) |
C14—C13—C9—C3 | −89.3 (3) | C20—C26—C30—C29 | 139.1 (2) |
C14—C13—C9—C10 | 150.7 (3) | C20—C26—C30—C31 | −92.2 (3) |
C14—C13—C9—C16 | 39.8 (4) | C20—C21—C18—C23 | −157.5 (2) |
C14—C13—C12—C11 | −144.6 (3) | C20—C21—C18—C24 | 78.6 (3) |
C13—C14—C15—C5 | −50.0 (4) | C20—C21—C22—O7 | 157.5 (2) |
C13—C9—C3—O1 | 153.9 (2) | C20—C21—C22—C32 | −87.5 (3) |
C13—C9—C3—C4 | 31.1 (3) | C21—C18—C23—O9 | −162.1 (3) |
C13—C9—C10—O5 | 159.5 (3) | C21—C18—C23—O7 | 17.2 (3) |
C13—C9—C10—C11 | −21.3 (3) | C18—C21—C22—O7 | 28.2 (3) |
C13—C12—C11—C10 | 2.7 (4) | C18—C21—C22—C32 | 143.2 (3) |
C9—C13—C12—C11 | −16.2 (3) | C23—O7—C22—C21 | −18.7 (3) |
C9—C3—C4—C5 | 43.8 (3) | C23—O7—C22—C32 | −140.3 (3) |
C9—C3—C4—C1 | 165.0 (3) | C19—O6—C20—C26 | 122.9 (3) |
C3—O1—C2—O3 | 7.6 (4) | C19—O6—C20—C21 | −112.5 (3) |
C3—O1—C2—C8 | −172.7 (3) | C33—C26—C20—O6 | 31.6 (3) |
C3—C9—C10—O5 | 37.0 (4) | C33—C26—C20—C21 | −90.6 (3) |
C3—C9—C10—C11 | −143.8 (3) | C33—C26—C30—C29 | −91.7 (3) |
C3—C4—C1—C6 | −158.2 (3) | C33—C26—C30—C31 | 37.0 (4) |
C3—C4—C1—C7 | 77.8 (4) | C28—C27—C26—C20 | −139.5 (2) |
C2—O1—C3—C9 | 125.7 (3) | C28—C27—C26—C33 | 98.3 (3) |
C2—O1—C3—C4 | −109.0 (3) | C28—C27—C26—C30 | −18.5 (3) |
C6—O2—C5—C15 | −141.7 (3) | C28—C29—C30—C26 | −12.8 (3) |
C6—O2—C5—C4 | −18.8 (3) | C28—C29—C30—C31 | −141.1 (3) |
C5—O2—C6—O4 | 179.6 (3) | C29—C30—C31—C32 | −167.1 (3) |
C5—O2—C6—C1 | −0.8 (4) | C29—C30—C31—C34 | −45.7 (4) |
C5—C4—C1—C6 | −30.0 (3) | C30—C26—C20—O6 | 160.3 (2) |
C5—C4—C1—C7 | −154.1 (3) | C30—C26—C20—C21 | 38.0 (3) |
C15—C14—C13—C9 | 75.2 (3) | C30—C31—C32—C22 | −46.3 (4) |
C15—C14—C13—C12 | −163.5 (3) | C31—C32—C22—O7 | 179.2 (3) |
C15—C5—C4—C3 | −87.3 (3) | C31—C32—C22—C21 | 65.0 (4) |
C15—C5—C4—C1 | 145.2 (3) | C22—O7—C23—O9 | −179.7 (3) |
C12—C13—C9—C3 | 141.5 (3) | C22—O7—C23—C18 | 0.9 (3) |
C12—C13—C9—C10 | 21.5 (3) | C22—C21—C18—C23 | −27.1 (3) |
C12—C13—C9—C16 | −89.4 (3) | C22—C21—C18—C24 | −151.0 (3) |
C12—C11—C10—O5 | −168.5 (4) | C24—C18—C23—O9 | −37.3 (5) |
C12—C11—C10—C9 | 12.4 (4) | C24—C18—C23—O7 | 142.1 (3) |
C10—C9—C3—O1 | −91.1 (3) | C34—C31—C32—C22 | −170.3 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
C4—H4···O4i | 1.00 | 2.50 | 3.324 (4) | 139 |
C21—H21···O5ii | 1.00 | 2.44 | 3.421 (4) | 167 |
Symmetry codes: (i) x−1/2, −y+1/2, −z; (ii) −x+1, y+1/2, −z+1/2. |
D—H···A | D—H | H···A | D···A | D—H···A |
C4—H4···O4i | 1.00 | 2.50 | 3.324 (4) | 139.1 |
C21—H21···O5ii | 1.00 | 2.44 | 3.421 (4) | 167.3 |
Symmetry codes: (i) x−1/2, −y+1/2, −z; (ii) −x+1, y+1/2, −z+1/2. |
Acknowledgements
Acknowledgements are made to the National Science Foundation MRI Program (CHE-0951711) and the Grote Chemistry Fund at the University of Tennessee at Chattanooga for their generous support of our work.
References
Barton, D. H. R. & De Mayo, P. (1956). J. Chem. Soc. pp. 142–149. CrossRef Web of Science Google Scholar
Braun, B. H., Herz, W. & Rabindran, K. (1956). J. Am. Chem. Soc. 78, 4423–4429. CrossRef CAS Web of Science Google Scholar
Bruker (2009). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Clark, E. P. (1939). J. Am. Chem. Soc. 61, 1836–1840. CrossRef CAS Google Scholar
Dolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339–341. Web of Science CrossRef CAS IUCr Journals Google Scholar
Herz, W. & Sharma, R. P. (1975). J. Org. Chem. 40, 2557–2559. CrossRef CAS Web of Science Google Scholar
Hodge, J. S. & Waddell, T. G. (1995). J. Nat. Prod. 58, 149–151. CrossRef CAS Web of Science Google Scholar
Knight, K. S., Smith, C. T., Waddell, T. G. & Noll, B. (2013). Acta Cryst. E69, o1237–o1238. CSD CrossRef IUCr Journals Google Scholar
Lee, K. H., Hall, I. H., Mar, E. C., Starnes, C. O., ElGebaly, S. A., Waddell, T. G., Hadgraft, R. I., Ruffner, C. G. & Weidner, I. (1977). Science, 196, 533–536. CrossRef PubMed CAS Web of Science Google Scholar
Li, X.-J. & Zhang, H.-Y. (2008). Trends Mol. Med. 14, 1–2. Web of Science CrossRef PubMed Google Scholar
Mazhar-Ul-Haque, Rogers, D. & Caughlan, C. N. (1974). J. Chem. Soc. Perkin Trans. 2, pp. 223–228. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
Isotenulin, C17H22O5, is a sesquiterpene lactone isolated from sneezeweed Helenium amarum, a medicinal plant native to the southeastern USA. The crystal structure contains two independent tenulin molecules. These two conformations are distinguished by the way in which the five membered rings twist relative to each other, as measured by the magnitude of the dihedral angles at the cycloheptane-cyclopentenone and cycloheptane-lactone ring junctures. In the more twisted conformation, the dihedral angle of the substituents on the cycloheptane ring that form the cyclopentenone is 21.5 (1)°, while that of the lactone is 30.2 (1)°. Those values for the less twisted conformer are 18.1 (1)° and 28.2 (1)° respectively. The absolute configuration of all other stereocenters is that established for other sesquiterpene lactones (Mazhar-Ul-Haque et al., 1974).