Crystal structure of pseudoguainolide

Abstract

The lactone ring in the title mol­ecule, C₁₅H₂₂O₃ (systematic name: 3,4a,8-tri­methyl­dodeca­hydro­azuleno[6,5-b]furan-2,5-dione), assumes an envelope conformation with the methine C atom adjacent to the the methine C atom carrying the methyl substituent being the flap atom. The other five-membered ring adopts a twisted conformation with the twist being about the methine–methyl­ene C—C bond. The seven-membered ring is based on a twisted boat conformation. No specific inter­actions are noted in the the crystal packing.

Related literature  

For background to inula graveolens, see: Chiappini & Fardella (1980 ▸); Rustaiyan et al. (1987 ▸). For related structures, see: Herz et al. (1982 ▸); Schmidt et al. (1996 ▸); Wu et al. (2012 ▸); Billodeaux et al. (2014 ▸).

Experimental  

Crystal data  

• C₁₅H₂₂O₃

• M _r = 250.33

• Orthorhombic,

• a = 7.4320 (3) Å

• b = 11.9278 (3) Å

• c = 15.3152 (6) Å

• V = 1357.65 (8) ų

• Z = 4

• Mo Kα radiation

• μ = 0.08 mm⁻¹

• T = 150 K

• 0.20 × 0.20 × 0.04 mm

Data collection  

• Nonius KappaCCD diffractometer

• Absorption correction: multi-scan (DENZO/SCALEPACK; Otwinowski & Minor, 1997 ▸) T _min = 0.984, T _max = 0.997

• 9382 measured reflections

• 3098 independent reflections

• 2533 reflections with I > 2σ(I)

• R _int = 0.041

Refinement  

• R[F ² > 2σ(F ²)] = 0.047

• wR(F ²) = 0.107

• S = 1.08

• 3098 reflections

• 166 parameters

• H-atom parameters constrained

• Δρ_max = 0.15 e Å⁻³

• Δρ_min = −0.16 e Å⁻³

Data collection: COLLECT (Nonius, 2000 ▸); cell refinement: SCALEPACK (Otwinowski & Minor, 1997 ▸); data reduction: DENZO (Otwinowski & Minor, 1997 ▸) and SCALEPACK; program(s) used to solve structure: SIR92 (Altomare et al., 1999 ▸); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▸); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ▸); software used to prepare material for publication: WinGX (Farrugia, 2012 ▸).

Supplementary Material

CCDC reference: 1047797

Additional supporting information: crystallographic information; 3D view; checkCIF report

supplementary crystallographic information

S1. Comment

Inula graveolens have consistently been the subject of research interest (Chiappini & Fardella, 1980; Rustaiyan et al., 1987). Our interest is in the extracts from aerial parts of Algerian species such as stems, flowers and leaves. The asymmetric unit of the crystal structure consists of a single molecule (Fig. 1). In the molecule, the lactone ring assumes an envelope conformation. In the crystal structure, the planes of the lactone rings are approximately parallel. The molecules are arranged with the lactone rings stacked parallel to the a axis. Structures of some related compounds have been reported (Herz et al., 1982; Schmidt et al., 1996; Wu et al., 2012; Billodeaux et al., 2014).

S2. Experimental

The air-dried aerial parts of inula graveolens (500 g) were extracted with acetone/Et₂O (1:1) at room temperature. The solution was filtered off and concentrated under reduced pressure to give a pale-yellow gum (9 g). The gum was subjected to successive column chromatography (silica gel) and TLC (silica gel, PF254). Eleven fractions were obtained. Fraction 5 gave a material which crystallized as colourless crystals with a melting point of 152 ^oC.

S3. Refinement

Carbon-bound H-atoms were placed in calculated positions (C—H = 0.96–0.98 Å) and were included in the refinement in the riding model approximation, with U_iso(H) set to 1.2–1.5U_equiv(C).

Figures

Fig. 1.

A molecule showing atom labels and 50% probability displacement ellipsoids for non-H atoms.

Crystal data

C15H22O3	Dx = 1.225 Mg m−3
Mr = 250.33	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, P212121	Cell parameters from 3098 reflections
a = 7.4320 (3) Å	θ = 3.1–27.5°
b = 11.9278 (3) Å	µ = 0.08 mm−1
c = 15.3152 (6) Å	T = 150 K
V = 1357.65 (8) Å3	Plate, colourless
Z = 4	0.20 × 0.20 × 0.04 mm
F(000) = 544

Data collection

Nonius KappaCCD diffractometer	3098 independent reflections
Radiation source: fine-focus sealed tube	2533 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.041
CCD slices, ω and φ scans	θmax = 27.5°, θmin = 3.1°
Absorption correction: multi-scan (DENZO/SCALEPACK; Otwinowski & Minor, 1997)	h = −9→9
Tmin = 0.984, Tmax = 0.997	k = −15→15
9382 measured reflections	l = −19→17

Refinement

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)] = 0.047	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.107	H-atom parameters constrained
S = 1.08	w = 1/[σ2(Fo2) + (0.0453P)2 + 0.2031P] where P = (Fo2 + 2Fc2)/3
3098 reflections	(Δ/σ)max < 0.001
166 parameters	Δρmax = 0.15 e Å−3
0 restraints	Δρmin = −0.16 e Å−3

Special details

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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 (Ų)

	x	y	z	Uiso*/Ueq
C1	0.8136 (2)	0.24699 (16)	0.52812 (12)	0.0383 (4)
C2	0.8423 (3)	0.16380 (15)	0.45546 (12)	0.0407 (4)
H2	0.9722	0.1503	0.4522	0.049*
C3	0.7918 (2)	0.22980 (13)	0.37360 (11)	0.0318 (4)
H3	0.6620	0.2220	0.3642	0.038*
C4	0.8307 (2)	0.35109 (14)	0.40005 (11)	0.0338 (4)
H4	0.9552	0.3703	0.3852	0.041*
C5	0.8884 (2)	0.19024 (14)	0.29170 (12)	0.0346 (4)
H5A	0.8386	0.1183	0.2748	0.041*
H5B	1.0142	0.1785	0.3060	0.041*
C6	0.8781 (2)	0.26974 (15)	0.21218 (12)	0.0371 (4)
C7	0.7099 (3)	0.34762 (15)	0.20872 (12)	0.0388 (4)
H7	0.6065	0.3039	0.2292	0.047*
C8	0.7176 (3)	0.45618 (14)	0.26350 (13)	0.0429 (5)
H8	0.8326	0.4932	0.2513	0.052*
C9	0.7050 (3)	0.43722 (14)	0.36244 (12)	0.0396 (4)
H9A	0.7276	0.5081	0.3914	0.048*
H9B	0.5827	0.4152	0.3763	0.048*
C10	0.8618 (3)	0.20169 (18)	0.12824 (14)	0.0495 (5)
C11	0.7283 (4)	0.25562 (19)	0.06728 (14)	0.0630 (6)
H11A	0.6211	0.2099	0.0617	0.076*
H11B	0.7805	0.2665	0.0098	0.076*
C12	0.6842 (3)	0.36830 (18)	0.10993 (14)	0.0583 (6)
H12A	0.5613	0.3905	0.0973	0.070*
H12B	0.7651	0.4264	0.0893	0.070*
C13	0.7564 (3)	0.05319 (14)	0.47094 (13)	0.0453 (5)
H13A	0.6282	0.0623	0.4737	0.068*
H13B	0.7992	0.0226	0.5251	0.068*
H13C	0.7864	0.0032	0.4240	0.068*
C14	1.0567 (3)	0.33493 (19)	0.20250 (15)	0.0519 (5)
H14A	1.0488	0.3846	0.1533	0.078*
H14B	1.1536	0.2830	0.1937	0.078*
H14C	1.0786	0.3777	0.2545	0.078*
C15	0.5664 (3)	0.53701 (18)	0.23775 (17)	0.0650 (7)
H15A	0.5670	0.6004	0.2764	0.098*
H15B	0.4526	0.4992	0.2419	0.098*
H15C	0.5847	0.5620	0.1788	0.098*
O1	0.79726 (18)	0.22938 (12)	0.60507 (9)	0.0478 (3)
O2	0.80792 (16)	0.35200 (10)	0.49559 (7)	0.0390 (3)
O3	0.9465 (2)	0.11791 (15)	0.11224 (11)	0.0721 (5)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
C1	0.0265 (8)	0.0451 (10)	0.0433 (11)	−0.0014 (8)	−0.0003 (8)	0.0008 (8)
C2	0.0416 (10)	0.0404 (9)	0.0400 (10)	−0.0014 (8)	0.0015 (8)	0.0040 (8)
C3	0.0265 (8)	0.0298 (8)	0.0392 (9)	−0.0018 (7)	0.0004 (7)	0.0008 (7)
C4	0.0296 (9)	0.0335 (8)	0.0384 (9)	−0.0040 (7)	0.0040 (7)	−0.0020 (7)
C5	0.0314 (9)	0.0331 (9)	0.0393 (10)	0.0025 (7)	−0.0013 (8)	−0.0011 (7)
C6	0.0344 (9)	0.0381 (9)	0.0387 (10)	−0.0011 (8)	0.0020 (8)	0.0015 (8)
C7	0.0381 (9)	0.0357 (8)	0.0426 (10)	0.0007 (8)	−0.0058 (8)	0.0050 (8)
C8	0.0453 (11)	0.0301 (8)	0.0534 (12)	0.0008 (9)	0.0005 (9)	0.0064 (8)
C9	0.0373 (10)	0.0303 (8)	0.0512 (11)	−0.0012 (8)	0.0023 (9)	−0.0031 (7)
C10	0.0526 (12)	0.0532 (12)	0.0426 (12)	0.0015 (10)	−0.0019 (9)	−0.0027 (9)
C11	0.0807 (17)	0.0660 (14)	0.0424 (12)	0.0121 (14)	−0.0134 (12)	−0.0037 (10)
C12	0.0731 (15)	0.0544 (12)	0.0472 (12)	0.0092 (12)	−0.0115 (12)	0.0079 (9)
C13	0.0473 (11)	0.0383 (10)	0.0502 (12)	0.0076 (9)	0.0064 (9)	0.0056 (8)
C14	0.0441 (11)	0.0595 (12)	0.0522 (13)	−0.0096 (10)	0.0101 (10)	0.0073 (10)
C15	0.0772 (17)	0.0419 (11)	0.0761 (17)	0.0178 (12)	−0.0123 (14)	0.0068 (11)
O1	0.0432 (8)	0.0636 (8)	0.0367 (8)	−0.0003 (7)	0.0028 (6)	0.0023 (6)
O2	0.0380 (7)	0.0401 (7)	0.0388 (7)	−0.0038 (6)	0.0016 (6)	−0.0055 (5)
O3	0.0840 (12)	0.0763 (11)	0.0560 (10)	0.0307 (10)	−0.0134 (9)	−0.0248 (9)

Geometric parameters (Å, º)

C1—O1	1.203 (2)	C8—C15	1.532 (3)
C1—O2	1.349 (2)	C8—C9	1.535 (3)
C1—C2	1.506 (3)	C8—H8	0.9800
C2—C13	1.485 (2)	C9—H9A	0.9700
C2—C3	1.527 (2)	C9—H9B	0.9700
C2—H2	0.9800	C10—O3	1.206 (2)
C3—C5	1.520 (2)	C10—C11	1.507 (3)
C3—C4	1.530 (2)	C11—C12	1.530 (3)
C3—H3	0.9800	C11—H11A	0.9700
C4—O2	1.473 (2)	C11—H11B	0.9700
C4—C9	1.503 (2)	C12—H12A	0.9700
C4—H4	0.9800	C12—H12B	0.9700
C5—C6	1.545 (3)	C13—H13A	0.9600
C5—H5A	0.9700	C13—H13B	0.9600
C5—H5B	0.9700	C13—H13C	0.9600
C6—C10	1.525 (3)	C14—H14A	0.9600
C6—C14	1.546 (3)	C14—H14B	0.9600
C6—C7	1.558 (3)	C14—H14C	0.9600
C7—C8	1.544 (3)	C15—H15A	0.9600
C7—C12	1.545 (3)	C15—H15B	0.9600
C7—H7	0.9800	C15—H15C	0.9600
O1—C1—O2	121.39 (17)	C9—C8—H8	107.9
O1—C1—C2	128.53 (18)	C7—C8—H8	107.9
O2—C1—C2	110.08 (15)	C4—C9—C8	116.18 (15)
C13—C2—C1	114.00 (15)	C4—C9—H9A	108.2
C13—C2—C3	118.92 (16)	C8—C9—H9A	108.2
C1—C2—C3	103.43 (14)	C4—C9—H9B	108.2
C13—C2—H2	106.6	C8—C9—H9B	108.2
C1—C2—H2	106.6	H9A—C9—H9B	107.4
C3—C2—H2	106.6	O3—C10—C11	124.8 (2)
C5—C3—C2	113.67 (14)	O3—C10—C6	124.83 (19)
C5—C3—C4	115.01 (14)	C11—C10—C6	110.31 (17)
C2—C3—C4	102.93 (13)	C10—C11—C12	104.58 (18)
C5—C3—H3	108.3	C10—C11—H11A	110.8
C2—C3—H3	108.3	C12—C11—H11A	110.8
C4—C3—H3	108.3	C10—C11—H11B	110.8
O2—C4—C9	107.71 (13)	C12—C11—H11B	110.8
O2—C4—C3	104.38 (13)	H11A—C11—H11B	108.9
C9—C4—C3	115.32 (15)	C11—C12—C7	104.55 (16)
O2—C4—H4	109.7	C11—C12—H12A	110.8
C9—C4—H4	109.7	C7—C12—H12A	110.8
C3—C4—H4	109.7	C11—C12—H12B	110.8
C3—C5—C6	115.87 (13)	C7—C12—H12B	110.8
C3—C5—H5A	108.3	H12A—C12—H12B	108.9
C6—C5—H5A	108.3	C2—C13—H13A	109.5
C3—C5—H5B	108.3	C2—C13—H13B	109.5
C6—C5—H5B	108.3	H13A—C13—H13B	109.5
H5A—C5—H5B	107.4	C2—C13—H13C	109.5
C10—C6—C5	109.98 (14)	H13A—C13—H13C	109.5
C10—C6—C14	104.76 (16)	H13B—C13—H13C	109.5
C5—C6—C14	109.96 (15)	C6—C14—H14A	109.5
C10—C6—C7	103.01 (15)	C6—C14—H14B	109.5
C5—C6—C7	115.63 (14)	H14A—C14—H14B	109.5
C14—C6—C7	112.70 (14)	C6—C14—H14C	109.5
C8—C7—C12	113.76 (15)	H14A—C14—H14C	109.5
C8—C7—C6	116.85 (15)	H14B—C14—H14C	109.5
C12—C7—C6	103.16 (15)	C8—C15—H15A	109.5
C8—C7—H7	107.5	C8—C15—H15B	109.5
C12—C7—H7	107.5	H15A—C15—H15B	109.5
C6—C7—H7	107.5	C8—C15—H15C	109.5
C15—C8—C9	107.59 (17)	H15A—C15—H15C	109.5
C15—C8—C7	111.13 (17)	H15B—C15—H15C	109.5
C9—C8—C7	114.24 (14)	C1—O2—C4	110.89 (13)
C15—C8—H8	107.9