Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270199016522/fr1250sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270199016522/fr1250IIIsup2.hkl |
CCDC reference: 143274
To a solution of lithium diisopropylamide (5 equivalents) in tetrahydrofuran (thf) at 195 K was added dropwise over one minute the lactone ester (II) (see scheme above) (1 equivalent) in thf. The solution was stirred at 195 K for 1 h and the reaction was quenched and diluted with water. Methylene chloride (40 ml) was added and then the organic and aqueous layers were separated. The organic layer was dried over sodium sulfate, concentrated in vacuo and the residue purified by silica-gel flash chromatography.
The H atoms were idealized as follows: O3 and O3A with O—H = 0.84 Å; secondary CH2 with C—H = 0.99 Å; tertiary sp3 C with C—H = 1.00 Å; C12 and C12A as idealized terminal CH2 with C—H = 0.99 Å; methyl groups with C—H = 0.98 Å.
Data collection: SMART (Bruker, 1996); cell refinement: SMART; data reduction: SHELXTL (Sheldrick, 1997); program(s) used to solve structure: SHELXTL; program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.
Fig. 1. Molecular structure of (III) drawn with displacement ellipsoids at the 30% probability level. |
C14H20O4 | Dx = 1.252 Mg m−3 |
Mr = 252.30 | Mo Kα radiation, λ = 0.71073 Å |
Orthorhombic, P212121 | Cell parameters from 4161 reflections |
a = 9.3933 (7) Å | θ = 3–26° |
b = 9.3963 (7) Å | µ = 0.09 mm−1 |
c = 30.329 (2) Å | T = 193 K |
V = 2676.9 (3) Å3 | Plate, colourless |
Z = 8 | 0.41 × 0.38 × 0.05 mm |
F(000) = 1088 |
CCD area-detector diffractometer | 3066 independent reflections |
Radiation source: fine-focus sealed tube | 2383 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.026 |
ω scans | θmax = 26.4°, θmin = 2.6° |
Absorption correction: empirical (using intensity measurements) (SADABS; Blessing, 1995) | h = −11→11 |
Tmin = 0.964, Tmax = 0.996 | k = 0→11 |
12722 measured reflections | l = 0→37 |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.038 | H-atom parameters constrained |
wR(F2) = 0.079 | w = 1/[σ2(Fo2) + (0.030P)2] where P = (Fo2 + 2Fc2)/3 |
S = 1.05 | (Δ/σ)max = 0.001 |
3066 reflections | Δρmax = 0.15 e Å−3 |
329 parameters | Δρmin = −0.20 e Å−3 |
0 restraints | Absolute structure: Flack H D (1983), Acta Cryst. A39, 876-881 |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: −0.6 (10) |
C14H20O4 | V = 2676.9 (3) Å3 |
Mr = 252.30 | Z = 8 |
Orthorhombic, P212121 | Mo Kα radiation |
a = 9.3933 (7) Å | µ = 0.09 mm−1 |
b = 9.3963 (7) Å | T = 193 K |
c = 30.329 (2) Å | 0.41 × 0.38 × 0.05 mm |
CCD area-detector diffractometer | 3066 independent reflections |
Absorption correction: empirical (using intensity measurements) (SADABS; Blessing, 1995) | 2383 reflections with I > 2σ(I) |
Tmin = 0.964, Tmax = 0.996 | Rint = 0.026 |
12722 measured reflections |
R[F2 > 2σ(F2)] = 0.038 | H-atom parameters constrained |
wR(F2) = 0.079 | Δρmax = 0.15 e Å−3 |
S = 1.05 | Δρmin = −0.20 e Å−3 |
3066 reflections | Absolute structure: Flack H D (1983), Acta Cryst. A39, 876-881 |
329 parameters | Absolute structure parameter: −0.6 (10) |
0 restraints |
Experimental. Since in light atom structures the absolute configuration could not be established with Mo radiation it is preferred to merge Fridel pairs. The Friedel opposites were merged in this structure and therefore Flack test is meaningless and the Fridel pair count is zero. |
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 | 0.15553 (16) | 0.41949 (18) | 1.02207 (4) | 0.0495 (4) | |
O2 | 0.28755 (13) | 0.39824 (15) | 1.08190 (4) | 0.0303 (3) | |
O3 | 0.54004 (15) | 0.12257 (16) | 1.06394 (4) | 0.0447 (4) | |
H3 | 0.5717 | 0.0905 | 1.0400 | 0.067* | |
O4 | 0.56494 (16) | 0.35562 (18) | 1.04012 (4) | 0.0496 (4) | |
C1 | 0.2512 (2) | 0.3585 (2) | 1.04054 (6) | 0.0350 (5) | |
C2 | 0.3439 (2) | 0.2397 (2) | 1.02510 (5) | 0.0346 (5) | |
H2A | 0.3737 | 0.2538 | 0.9941 | 0.042* | |
H2B | 0.2951 | 0.1468 | 1.0278 | 0.042* | |
C3 | 0.4693 (2) | 0.2499 (2) | 1.05623 (6) | 0.0331 (5) | |
C4 | 0.40815 (18) | 0.3132 (2) | 1.09890 (5) | 0.0261 (5) | |
C5 | 0.34739 (18) | 0.2125 (2) | 1.13320 (5) | 0.0287 (5) | |
H5A | 0.2893 | 0.1395 | 1.1180 | 0.034* | |
H5B | 0.2833 | 0.2669 | 1.1529 | 0.034* | |
C6 | 0.4595 (2) | 0.1375 (2) | 1.16133 (5) | 0.0343 (5) | |
H6 | 0.5116 | 0.0703 | 1.1415 | 0.041* | |
C7 | 0.5687 (2) | 0.2444 (3) | 1.17874 (6) | 0.0456 (6) | |
H7A | 0.5219 | 0.3096 | 1.1999 | 0.055* | |
H7B | 0.6449 | 0.1928 | 1.1947 | 0.055* | |
C8 | 0.6341 (2) | 0.3305 (3) | 1.14135 (6) | 0.0419 (6) | |
H8A | 0.6840 | 0.2650 | 1.1210 | 0.050* | |
H8B | 0.7055 | 0.3968 | 1.1537 | 0.050* | |
C9 | 0.52287 (19) | 0.4162 (2) | 1.11521 (6) | 0.0326 (5) | |
C10 | 0.5851 (2) | 0.4661 (3) | 1.07154 (6) | 0.0459 (6) | |
H10A | 0.5365 | 0.5540 | 1.0616 | 0.055* | |
H10B | 0.6878 | 0.4869 | 1.0750 | 0.055* | |
C11 | 0.3939 (2) | 0.0488 (3) | 1.19796 (6) | 0.0432 (6) | |
C12 | 0.4142 (3) | −0.0902 (3) | 1.19896 (7) | 0.0693 (8) | |
H12A | 0.3735 | −0.1455 | 1.2220 | 0.083* | |
H12B | 0.4694 | −0.1349 | 1.1767 | 0.083* | |
C13 | 0.3090 (3) | 0.1219 (4) | 1.23184 (8) | 0.0890 (11) | |
H13A | 0.2704 | 0.0517 | 1.2525 | 0.134* | |
H13B | 0.2305 | 0.1734 | 1.2177 | 0.134* | |
H13C | 0.3695 | 0.1894 | 1.2478 | 0.134* | |
C14 | 0.4650 (2) | 0.5400 (2) | 1.14245 (7) | 0.0478 (6) | |
H14A | 0.3968 | 0.5944 | 1.1247 | 0.072* | |
H14B | 0.5438 | 0.6021 | 1.1513 | 0.072* | |
H14C | 0.4172 | 0.5029 | 1.1688 | 0.072* | |
O1A | 0.47359 (13) | 0.83021 (17) | 1.02475 (4) | 0.0435 (4) | |
O2A | 0.43260 (12) | 0.78332 (15) | 0.95392 (3) | 0.0320 (3) | |
O3A | 0.76168 (12) | 0.66972 (16) | 0.90771 (3) | 0.0349 (4) | |
H3A | 0.8316 | 0.6315 | 0.9203 | 0.052* | |
O4A | 0.60588 (14) | 0.51529 (17) | 0.94132 (4) | 0.0443 (4) | |
C1A | 0.51696 (19) | 0.7870 (2) | 0.98985 (6) | 0.0326 (5) | |
C2A | 0.66164 (19) | 0.7335 (2) | 0.97904 (5) | 0.0334 (5) | |
H2A1 | 0.6952 | 0.6652 | 1.0016 | 0.040* | |
H2A2 | 0.7306 | 0.8128 | 0.9769 | 0.040* | |
C3A | 0.64289 (18) | 0.6609 (2) | 0.93488 (5) | 0.0268 (5) | |
C4A | 0.50850 (18) | 0.7310 (2) | 0.91447 (5) | 0.0268 (5) | |
C5A | 0.52706 (18) | 0.8577 (2) | 0.88440 (5) | 0.0263 (5) | |
H5A1 | 0.5957 | 0.9242 | 0.8981 | 0.032* | |
H5A2 | 0.4347 | 0.9078 | 0.8820 | 0.032* | |
C6A | 0.5794 (2) | 0.8214 (2) | 0.83799 (5) | 0.0301 (5) | |
H6A | 0.6790 | 0.7850 | 0.8409 | 0.036* | |
C7A | 0.4893 (2) | 0.7007 (2) | 0.81864 (5) | 0.0377 (5) | |
H7A1 | 0.3909 | 0.7349 | 0.8137 | 0.045* | |
H7A2 | 0.5292 | 0.6718 | 0.7898 | 0.045* | |
C8A | 0.4864 (2) | 0.5726 (2) | 0.84947 (5) | 0.0391 (6) | |
H8A1 | 0.5847 | 0.5364 | 0.8532 | 0.047* | |
H8A2 | 0.4292 | 0.4961 | 0.8357 | 0.047* | |
C9A | 0.4240 (2) | 0.6067 (2) | 0.89519 (5) | 0.0339 (5) | |
C10A | 0.4626 (2) | 0.4875 (3) | 0.92755 (6) | 0.0439 (6) | |
H10C | 0.3974 | 0.4883 | 0.9532 | 0.053* | |
H10D | 0.4561 | 0.3935 | 0.9129 | 0.053* | |
C11A | 0.5843 (2) | 0.9493 (3) | 0.80774 (6) | 0.0361 (5) | |
C12A | 0.5312 (2) | 1.0750 (3) | 0.81757 (7) | 0.0504 (7) | |
H12C | 0.5390 | 1.1512 | 0.7972 | 0.061* | |
H12D | 0.4850 | 1.0894 | 0.8451 | 0.061* | |
C13A | 0.6577 (3) | 0.9254 (3) | 0.76409 (6) | 0.0570 (7) | |
H13D | 0.7518 | 0.8833 | 0.7692 | 0.086* | |
H13E | 0.6687 | 1.0167 | 0.7488 | 0.086* | |
H13F | 0.6005 | 0.8609 | 0.7459 | 0.086* | |
C14A | 0.2637 (2) | 0.6323 (3) | 0.89289 (7) | 0.0507 (7) | |
H14D | 0.2440 | 0.7108 | 0.8725 | 0.076* | |
H14E | 0.2279 | 0.6566 | 0.9223 | 0.076* | |
H14F | 0.2162 | 0.5458 | 0.8824 | 0.076* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0603 (10) | 0.0466 (12) | 0.0416 (8) | 0.0134 (9) | −0.0234 (8) | −0.0046 (8) |
O2 | 0.0341 (7) | 0.0299 (10) | 0.0270 (6) | 0.0089 (6) | −0.0063 (5) | −0.0022 (6) |
O3 | 0.0589 (9) | 0.0433 (11) | 0.0319 (7) | 0.0241 (8) | 0.0092 (7) | −0.0019 (7) |
O4 | 0.0551 (9) | 0.0536 (13) | 0.0400 (8) | −0.0138 (9) | 0.0175 (7) | 0.0024 (8) |
C1 | 0.0435 (12) | 0.0343 (15) | 0.0271 (10) | −0.0035 (11) | −0.0043 (9) | 0.0018 (9) |
C2 | 0.0512 (12) | 0.0302 (15) | 0.0223 (9) | 0.0005 (11) | 0.0009 (9) | −0.0012 (9) |
C3 | 0.0391 (11) | 0.0317 (15) | 0.0286 (9) | 0.0041 (10) | 0.0067 (9) | 0.0034 (9) |
C4 | 0.0257 (10) | 0.0240 (13) | 0.0288 (9) | 0.0076 (9) | −0.0019 (8) | 0.0019 (8) |
C5 | 0.0310 (10) | 0.0332 (14) | 0.0218 (8) | −0.0010 (10) | 0.0026 (8) | −0.0024 (9) |
C6 | 0.0407 (11) | 0.0344 (15) | 0.0279 (9) | 0.0071 (11) | 0.0011 (9) | 0.0047 (9) |
C7 | 0.0385 (12) | 0.0594 (19) | 0.0388 (10) | 0.0056 (12) | −0.0138 (9) | 0.0079 (11) |
C8 | 0.0307 (11) | 0.0492 (18) | 0.0457 (11) | −0.0015 (11) | −0.0073 (9) | 0.0037 (11) |
C9 | 0.0312 (11) | 0.0304 (14) | 0.0362 (10) | −0.0021 (10) | −0.0032 (8) | 0.0002 (10) |
C10 | 0.0454 (12) | 0.0412 (17) | 0.0511 (13) | −0.0098 (12) | 0.0028 (11) | 0.0067 (11) |
C11 | 0.0522 (14) | 0.0487 (19) | 0.0288 (11) | 0.0019 (12) | −0.0067 (9) | 0.0097 (10) |
C12 | 0.113 (2) | 0.047 (2) | 0.0479 (13) | −0.0068 (19) | −0.0033 (14) | 0.0197 (13) |
C13 | 0.105 (2) | 0.105 (3) | 0.0570 (15) | 0.020 (2) | 0.0370 (15) | 0.0318 (18) |
C14 | 0.0538 (13) | 0.0406 (18) | 0.0488 (12) | −0.0030 (12) | −0.0113 (11) | −0.0072 (11) |
O1A | 0.0350 (7) | 0.0674 (13) | 0.0283 (7) | −0.0044 (8) | 0.0070 (6) | −0.0120 (7) |
O2A | 0.0236 (6) | 0.0492 (10) | 0.0232 (6) | −0.0036 (7) | 0.0015 (5) | −0.0020 (6) |
O3A | 0.0270 (7) | 0.0544 (12) | 0.0232 (6) | 0.0072 (7) | 0.0018 (5) | 0.0043 (6) |
O4A | 0.0492 (9) | 0.0335 (11) | 0.0501 (8) | −0.0032 (8) | −0.0072 (7) | 0.0103 (7) |
C1A | 0.0293 (10) | 0.0421 (15) | 0.0262 (9) | −0.0109 (10) | 0.0003 (8) | 0.0014 (9) |
C2A | 0.0283 (10) | 0.0479 (16) | 0.0241 (9) | −0.0003 (10) | −0.0027 (8) | 0.0013 (10) |
C3A | 0.0292 (10) | 0.0277 (14) | 0.0235 (9) | −0.0007 (9) | 0.0014 (8) | 0.0024 (8) |
C4A | 0.0254 (10) | 0.0343 (14) | 0.0206 (8) | −0.0025 (9) | 0.0017 (7) | −0.0008 (9) |
C5A | 0.0239 (9) | 0.0305 (13) | 0.0246 (8) | 0.0008 (9) | −0.0036 (7) | 0.0016 (8) |
C6A | 0.0288 (10) | 0.0358 (15) | 0.0257 (9) | −0.0017 (10) | −0.0050 (8) | 0.0024 (9) |
C7A | 0.0464 (12) | 0.0413 (15) | 0.0254 (9) | −0.0051 (11) | −0.0059 (9) | 0.0022 (9) |
C8A | 0.0483 (13) | 0.0385 (16) | 0.0304 (10) | −0.0104 (11) | −0.0074 (9) | −0.0030 (9) |
C9A | 0.0349 (11) | 0.0361 (14) | 0.0307 (9) | −0.0115 (10) | −0.0023 (9) | 0.0023 (10) |
C10A | 0.0521 (13) | 0.0379 (16) | 0.0418 (11) | −0.0132 (12) | −0.0005 (10) | 0.0052 (10) |
C11A | 0.0308 (11) | 0.0468 (17) | 0.0309 (10) | −0.0013 (11) | −0.0080 (8) | 0.0094 (10) |
C12A | 0.0470 (13) | 0.056 (2) | 0.0486 (12) | 0.0004 (13) | −0.0004 (11) | 0.0234 (13) |
C13A | 0.0754 (16) | 0.065 (2) | 0.0311 (10) | −0.0042 (15) | 0.0039 (11) | 0.0143 (12) |
C14A | 0.0372 (12) | 0.062 (2) | 0.0525 (12) | −0.0214 (12) | −0.0074 (10) | 0.0006 (13) |
O1—C1 | 1.204 (2) | O1A—C1A | 1.204 (2) |
O2—C1 | 1.353 (2) | O2A—C1A | 1.348 (2) |
O2—C4 | 1.479 (2) | O2A—C4A | 1.477 (2) |
O3—C3 | 1.388 (2) | O3A—C3A | 1.390 (2) |
O4—C10 | 1.422 (3) | O4A—C3A | 1.425 (3) |
O4—C3 | 1.426 (2) | O4A—C10A | 1.433 (2) |
C1—C2 | 1.491 (3) | C1A—C2A | 1.486 (3) |
C2—C3 | 1.513 (3) | C2A—C3A | 1.513 (2) |
C3—C4 | 1.536 (2) | C3A—C4A | 1.552 (3) |
C4—C5 | 1.517 (3) | C4A—C5A | 1.510 (3) |
C4—C9 | 1.531 (3) | C4A—C9A | 1.528 (3) |
C5—C6 | 1.528 (3) | C5A—C6A | 1.530 (2) |
C6—C11 | 1.519 (3) | C6A—C11A | 1.512 (3) |
C6—C7 | 1.530 (3) | C6A—C7A | 1.532 (3) |
C7—C8 | 1.522 (3) | C7A—C8A | 1.524 (3) |
C8—C9 | 1.539 (3) | C8A—C9A | 1.539 (2) |
C9—C10 | 1.522 (3) | C9A—C14A | 1.527 (3) |
C9—C14 | 1.527 (3) | C9A—C10A | 1.533 (3) |
C11—C12 | 1.321 (3) | C11A—C12A | 1.316 (3) |
C11—C13 | 1.471 (3) | C11A—C13A | 1.510 (3) |
C1—O2—C4 | 111.57 (15) | C1A—O2A—C4A | 112.32 (13) |
C10—O4—C3 | 111.30 (14) | C3A—O4A—C10A | 111.37 (16) |
O1—C1—O2 | 119.3 (2) | O1A—C1A—O2A | 121.35 (17) |
O1—C1—C2 | 130.24 (17) | O1A—C1A—C2A | 128.12 (16) |
O2—C1—C2 | 110.50 (17) | O2A—C1A—C2A | 110.52 (14) |
C1—C2—C3 | 102.21 (15) | C1A—C2A—C3A | 103.97 (14) |
O3—C3—O4 | 110.86 (16) | O3A—C3A—O4A | 109.54 (16) |
O3—C3—C2 | 115.07 (17) | O3A—C3A—C2A | 113.86 (15) |
O4—C3—C2 | 108.72 (15) | O4A—C3A—C2A | 109.86 (15) |
O3—C3—C4 | 111.76 (15) | O3A—C3A—C4A | 113.03 (13) |
O4—C3—C4 | 104.74 (16) | O4A—C3A—C4A | 105.28 (15) |
C2—C3—C4 | 105.03 (15) | C2A—C3A—C4A | 104.86 (15) |
O2—C4—C5 | 106.72 (14) | O2A—C4A—C5A | 106.39 (15) |
O2—C4—C9 | 108.06 (16) | O2A—C4A—C9A | 108.30 (14) |
C5—C4—C9 | 115.95 (14) | C5A—C4A—C9A | 115.56 (14) |
O2—C4—C3 | 101.64 (13) | O2A—C4A—C3A | 102.17 (12) |
C5—C4—C3 | 118.48 (17) | C5A—C4A—C3A | 118.77 (15) |
C9—C4—C3 | 104.72 (15) | C9A—C4A—C3A | 104.52 (17) |
C4—C5—C6 | 114.30 (15) | C4A—C5A—C6A | 114.65 (16) |
C11—C6—C5 | 112.46 (16) | C11A—C6A—C5A | 113.01 (17) |
C11—C6—C7 | 112.31 (15) | C11A—C6A—C7A | 111.85 (14) |
C5—C6—C7 | 110.61 (18) | C5A—C6A—C7A | 109.87 (15) |
C8—C7—C6 | 111.24 (15) | C8A—C7A—C6A | 111.06 (14) |
C7—C8—C9 | 112.85 (16) | C7A—C8A—C9A | 113.28 (18) |
C10—C9—C14 | 111.91 (19) | C14A—C9A—C4A | 114.17 (19) |
C10—C9—C4 | 100.61 (14) | C14A—C9A—C10A | 112.17 (17) |
C14—C9—C4 | 113.96 (16) | C4A—C9A—C10A | 101.00 (14) |
C10—C9—C8 | 110.42 (16) | C14A—C9A—C8A | 111.55 (15) |
C14—C9—C8 | 111.21 (16) | C4A—C9A—C8A | 107.82 (15) |
C4—C9—C8 | 108.24 (18) | C10A—C9A—C8A | 109.56 (18) |
O4—C10—C9 | 107.88 (18) | O4A—C10A—C9A | 105.96 (17) |
C12—C11—C13 | 121.6 (2) | C12A—C11A—C13A | 120.3 (2) |
C12—C11—C6 | 120.0 (2) | C12A—C11A—C6A | 124.33 (18) |
C13—C11—C6 | 118.4 (2) | C13A—C11A—C6A | 115.3 (2) |
C4—O2—C1—O1 | −179.15 (18) | C4A—O2A—C1A—O1A | 178.2 (2) |
C4—O2—C1—C2 | 0.5 (2) | C4A—O2A—C1A—C2A | −1.4 (2) |
O1—C1—C2—C3 | 160.9 (2) | O1A—C1A—C2A—C3A | 166.1 (2) |
O2—C1—C2—C3 | −18.7 (2) | O2A—C1A—C2A—C3A | −14.4 (2) |
C10—O4—C3—O3 | −111.79 (18) | C10A—O4A—C3A—O3A | −122.41 (15) |
C10—O4—C3—C2 | 120.77 (18) | C10A—O4A—C3A—C2A | 111.82 (17) |
C10—O4—C3—C4 | 8.9 (2) | C10A—O4A—C3A—C4A | −0.59 (18) |
C1—C2—C3—O3 | 152.06 (16) | C1A—C2A—C3A—O3A | 147.36 (17) |
C1—C2—C3—O4 | −82.93 (17) | C1A—C2A—C3A—O4A | −89.37 (19) |
C1—C2—C3—C4 | 28.7 (2) | C1A—C2A—C3A—C4A | 23.3 (2) |
C1—O2—C4—C5 | −107.18 (17) | C1A—O2A—C4A—C5A | −109.26 (17) |
C1—O2—C4—C9 | 127.47 (16) | C1A—O2A—C4A—C9A | 125.93 (16) |
C1—O2—C4—C3 | 17.6 (2) | C1A—O2A—C4A—C3A | 16.0 (2) |
O3—C3—C4—O2 | −153.80 (15) | O3A—C3A—C4A—O2A | −148.31 (15) |
O4—C3—C4—O2 | 86.10 (17) | O4A—C3A—C4A—O2A | 92.16 (16) |
C2—C3—C4—O2 | −28.4 (2) | C2A—C3A—C4A—O2A | −23.74 (19) |
O3—C3—C4—C5 | −37.3 (2) | O3A—C3A—C4A—C5A | −31.7 (2) |
O4—C3—C4—C5 | −157.42 (15) | O4A—C3A—C4A—C5A | −151.24 (15) |
C2—C3—C4—C5 | 88.11 (19) | C2A—C3A—C4A—C5A | 92.86 (18) |
O3—C3—C4—C9 | 93.78 (19) | O3A—C3A—C4A—C9A | 98.88 (18) |
O4—C3—C4—C9 | −26.32 (19) | O4A—C3A—C4A—C9A | −20.65 (17) |
C2—C3—C4—C9 | −140.80 (17) | C2A—C3A—C4A—C9A | −136.54 (15) |
O2—C4—C5—C6 | −167.89 (16) | O2A—C4A—C5A—C6A | −169.45 (13) |
C9—C4—C5—C6 | −47.5 (2) | C9A—C4A—C5A—C6A | −49.2 (2) |
C3—C4—C5—C6 | 78.4 (2) | C3A—C4A—C5A—C6A | 76.2 (2) |
C4—C5—C6—C11 | 174.55 (17) | C4A—C5A—C6A—C11A | 174.93 (15) |
C4—C5—C6—C7 | 48.1 (2) | C4A—C5A—C6A—C7A | 49.2 (2) |
C11—C6—C7—C8 | 179.32 (19) | C11A—C6A—C7A—C8A | 179.70 (16) |
C5—C6—C7—C8 | −54.1 (2) | C5A—C6A—C7A—C8A | −53.9 (2) |
C6—C7—C8—C9 | 60.0 (3) | C6A—C7A—C8A—C9A | 59.8 (2) |
O2—C4—C9—C10 | −75.58 (17) | O2A—C4A—C9A—C14A | 44.3 (2) |
C5—C4—C9—C10 | 164.73 (17) | C5A—C4A—C9A—C14A | −74.9 (2) |
C3—C4—C9—C10 | 32.18 (19) | C3A—C4A—C9A—C14A | 152.65 (15) |
O2—C4—C9—C14 | 44.3 (2) | O2A—C4A—C9A—C10A | −76.28 (18) |
C5—C4—C9—C14 | −75.4 (2) | C5A—C4A—C9A—C10A | 164.54 (15) |
C3—C4—C9—C14 | 152.09 (16) | C3A—C4A—C9A—C10A | 32.08 (17) |
O2—C4—C9—C8 | 168.60 (13) | O2A—C4A—C9A—C8A | 168.84 (15) |
C5—C4—C9—C8 | 48.9 (2) | C5A—C4A—C9A—C8A | 49.7 (2) |
C3—C4—C9—C8 | −83.63 (17) | C3A—C4A—C9A—C8A | −82.80 (17) |
C7—C8—C9—C10 | −164.34 (19) | C7A—C8A—C9A—C14A | 70.9 (2) |
C7—C8—C9—C14 | 70.8 (2) | C7A—C8A—C9A—C4A | −55.2 (2) |
C7—C8—C9—C4 | −55.1 (2) | C7A—C8A—C9A—C10A | −164.31 (16) |
C3—O4—C10—C9 | 12.3 (2) | C3A—O4A—C10A—C9A | 21.7 (2) |
C14—C9—C10—O4 | −149.01 (17) | C14A—C9A—C10A—O4A | −155.04 (17) |
C4—C9—C10—O4 | −27.6 (2) | C4A—C9A—C10A—O4A | −33.06 (19) |
C8—C9—C10—O4 | 86.5 (2) | C8A—C9A—C10A—O4A | 80.52 (19) |
C5—C6—C11—C12 | 118.2 (3) | C5A—C6A—C11A—C12A | −9.0 (3) |
C7—C6—C11—C12 | −116.3 (3) | C7A—C6A—C11A—C12A | 115.7 (2) |
C5—C6—C11—C13 | −62.1 (3) | C5A—C6A—C11A—C13A | 170.22 (17) |
C7—C6—C11—C13 | 63.4 (3) | C7A—C6A—C11A—C13A | −65.1 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
O3—H3···O1i | 0.84 | 2.04 | 2.853 (2) | 162 (1) |
O3A—H3A···O1Aii | 0.84 | 2.17 | 2.856 (2) | 140 (1) |
Symmetry codes: (i) x+1/2, −y+1/2, −z+2; (ii) x+1/2, −y+3/2, −z+2. |
Experimental details
Crystal data | |
Chemical formula | C14H20O4 |
Mr | 252.30 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 193 |
a, b, c (Å) | 9.3933 (7), 9.3963 (7), 30.329 (2) |
V (Å3) | 2676.9 (3) |
Z | 8 |
Radiation type | Mo Kα |
µ (mm−1) | 0.09 |
Crystal size (mm) | 0.41 × 0.38 × 0.05 |
Data collection | |
Diffractometer | CCD area-detector diffractometer |
Absorption correction | Empirical (using intensity measurements) (SADABS; Blessing, 1995) |
Tmin, Tmax | 0.964, 0.996 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 12722, 3066, 2383 |
Rint | 0.026 |
(sin θ/λ)max (Å−1) | 0.625 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.038, 0.079, 1.05 |
No. of reflections | 3066 |
No. of parameters | 329 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.15, −0.20 |
Absolute structure | Flack H D (1983), Acta Cryst. A39, 876-881 |
Absolute structure parameter | −0.6 (10) |
Computer programs: SMART (Bruker, 1996), SMART, SHELXTL (Sheldrick, 1997), SHELXTL.
D—H···A | D—H | H···A | D···A | D—H···A |
O3—H3···O1i | 0.84 | 2.04 | 2.853 (2) | 162 (1) |
O3A—H3A···O1Aii | 0.84 | 2.17 | 2.856 (2) | 140 (1) |
Symmetry codes: (i) x+1/2, −y+1/2, −z+2; (ii) x+1/2, −y+3/2, −z+2. |
Phytuberin, (I), is a metabolite induced by stress on potato stems and tobacco leaves (Fujimori et al., 1983). It is of interest from both a synthetic and a biological perspective since stress metabolites are a key part of certain signal transduction pathways (Preisig & Moreau, 1994). It also exhibits modest antifungal activity. An important step in the synthesis is the conversion of ester lactone (II) to lactone (III). Compound (II), upon treatment with 5 equivalents of lithium diisopropylamide (LDA) at 195 K, afforded lactone (III) in 93% yield (Bull & Tuinman, 1976). This step set the stereochemistry for the eventual conversion to phytuberin.
The title compound, (III), crystallizes in the chiral space group P212121 with two independent molecules in the asymmetric unit. A drawing of one molecule is shown in Fig. 1.
Both molecules exhibit remarkably similar conformations of the fused three-ring system and differ only in the conformation of the isopropenyl group. This difference is illustrated by the values of the C5—C6—C11—C13 torsion angles, which are -62.1 (3) and 170.2 (2)° in the two molecules, respectively. The absolute configuration of the compound could not be determined directly from the X-ray data; however, the absolute configuration about atom C6 (R) was known since it remained unchanged from the starting material (R)-2-methyl-5-(2-propenyl)-2-cyclohexenone throughout the four synthetic steps leading to the formation of (III). The absolute configurations about the other three chiral centres, C3 (R), C4 (R) and C9 (S), were established relative to that of atom C6 from the structural data. In the following discussion, the structural parameters for one molecule will be given in with those for the second molecule following in parentheses. The molecule of (III) contains two five-membered and one six-membered ring that have common vertices or edges. While all bond distances fall in the usual range for C—C and C—O distances, bond angles reflect strain present in the rings.
The cyclohexyl ring has a chair conformation with atoms C4, C5, C7 and C8 in the equatorial plane and atom C6 - 0.625 (3) Å[0.636 (3) Å] below and atom C9 0.646 (3) Å [-0.652 (s.u.?) Å] above the plane. Atoms C4, C5, C7 and C8 are planar within 0.05 Å (0.04 Å). The bond angles within the ring vary from 108.24 (18) to 115.95 (14)° [107.82 (15) to 115.56 (14)°]. The torsion angles range 47.49 (24)–59.97 (26)° [49.22 (21)–59.82 (22)°]. These data are in good agreement with the corresponding values calculated for dihydro and 2α-hydroxydihydro derivatives of phytuberin (Hughes, 1976), the only other two structurally characterized compounds containing a three ring system identical to that described here. Both five-membered rings in (III) exhibit envelope conformations. In the O2 ring, atoms C1, C2, C4 and O2 are planar within 0.003 Å (0.007 Å), while atom C3 is 0.465 (3) Å [0.390 (3) Å] above this plane. The dihedral angle between the C1–C2–C4–O2 plane and the `flap' plane defined by C2–C3–C4 is 30.1 (2)° [24.7 (2)°]. In the O4 ring, the equatorial plane contains atoms C3, C4, O4 and C10, which lie 0.05 Å (0.003 Å) within a plane, and atom C9, located 0.498 (4) Å [0.534 (3) Å] above that plane. The dihedral `flap' angle is 68.98 (20)° [41.41 (17)°].
The hydroxyl group at atom C3 participates in intermolecular O—H···O hydrogen bonding with an O···O separation of 2.853 (2) Å and an O—H···O angle of 162 (1)° (see Table 1). The analogous hydrogen bond formed by the hydroxyl group of the second molecule showed a similar O···O separation [2.856 (2) Å] but a significantly different O—H···O angle [140 (1)°] (see Table 1). In both cases the hydrogen bonds link molecules of (III) into one-dimensional linear chains.