5,9-Dihy-droxy-9-methyl-3,6-dimethyl-ene-3a,4,5,6,6a,7,8,9,9a,9b-deca-hydro-azuleno[4,5-b]furan-2(3H)-one.

The title compound, C(15)H(20)O(4), was synthesized from 9α-hy-droxy-parthenolide (9α-hy-droxy-4,8-dimethyl-12-methyl-ene-3,14-dioxatricyclo-[9.3.0.0(2,4)]tetra-dec-7-en-13-one), which was isolated from the chloro-form extract of the aerial parts of Anvillea radiata. The seven-membered ring has a chair conformation, while the five-membered rings display twisted conformations. The dihedral angle between the seven-membered ring and the lactone ring is 21.69 (10)°. In the crystal, mol-ecules are linked into chains propagating along the c axis by inter-molecular O-H⋯O hydrogen bonds; an intra-molecular O-H⋯O link also occurs.

Related literature

For background to the medicinal uses of the plant Anvillea radiata, see: Abdel Sattar et al. (1996 ▶); Bellakhdar (1997 ▶); El Hassany et al. (2004 ▶); Qureshi et al. (1990 ▶). For the reactivity of this sesquiterpene, see: El Haib et al. (2011 ▶). For ring puckering parameters, see: Cremer & Pople (1975 ▶).

Experimental

Crystal data

C15H20O4

M = 264.31

Orthorhombic,

a = 6.4210 (14) Å

b = 13.504 (3) Å

c = 15.619 (3) Å

V = 1354.4 (5) Å3

Z = 4

Mo Kα radiation

μ = 0.09 mm−1

T = 298 K

0.50 × 0.33 × 0.08 mm

Data collection

Bruker APEXII CCD area-detector diffractometer

14445 measured reflections

1610 independent reflections

1473 reflections with I > 2σ(I)

R int = 0.051

Refinement

R[F 2 > 2σ(F 2)] = 0.037

wR(F 2) = 0.097

S = 1.08

1610 reflections

175 parameters

H-atom parameters constrained

Δρmax = 0.20 e Å−3

Δρmin = −0.18 e Å−3

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: APEX2 and SAINT (Bruker, 2005 ▶); data reduction: SAINT; 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 ▶)and PLATON (Spek, 2009 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S160053681102352X/sj5165sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S160053681102352X/sj5165Isup2.hkl

Supplementary material file. DOI: 10.1107/S160053681102352X/sj5165Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C15H20O4	F(000) = 568
Mr = 264.31	Dx = 1.296 Mg m−3
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 14445 reflections
a = 6.4210 (14) Å	θ = 2–26.4°
b = 13.504 (3) Å	µ = 0.09 mm−1
c = 15.619 (3) Å	T = 298 K
V = 1354.4 (5) Å3	Platelet, colourless
Z = 4	0.50 × 0.33 × 0.08 mm

Bruker APEXII CCD area-detector diffractometer	1473 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.051
graphite	θmax = 26.4°, θmin = 2.0°
φ and ω scans	h = −8→8
14445 measured reflections	k = −16→16
1610 independent reflections	l = −19→18

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)] = 0.037	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.097	H-atom parameters constrained
S = 1.08	w = 1/[σ2(Fo2) + (0.0616P)2 + 0.1199P] where P = (Fo2 + 2Fc2)/3
1610 reflections	(Δ/σ)max = 0.002
175 parameters	Δρmax = 0.20 e Å−3
0 restraints	Δρmin = −0.18 e Å−3

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.

	x	y	z	Uiso*/Ueq
C13	0.5094 (4)	0.2383 (2)	0.65504 (15)	0.0622 (7)
H13A	0.6162	0.2666	0.6231	0.075*
H13B	0.5024	0.2493	0.7138	0.075*
C14	0.0186 (5)	−0.14917 (17)	0.73734 (18)	0.0636 (7)
H14A	−0.0277	−0.2020	0.7042	0.076*
H14B	0.1063	−0.1606	0.7837	0.076*
C15	0.0444 (4)	−0.12759 (19)	0.47662 (17)	0.0613 (7)
H15A	0.0015	−0.1705	0.4309	0.092*
H15B	0.0570	−0.1652	0.5285	0.092*
H15C	0.1764	−0.0984	0.4627	0.092*
C1	−0.1819 (3)	−0.02941 (14)	0.64505 (12)	0.0357 (4)
H1	−0.2819	0.0185	0.6681	0.043*
C2	−0.0403 (3)	−0.05775 (15)	0.71848 (12)	0.0398 (5)
C3	0.0356 (4)	0.02616 (16)	0.77685 (13)	0.0459 (5)
H3	0.0753	−0.0028	0.8320	0.055*
C4	0.2238 (4)	0.08094 (17)	0.74103 (12)	0.0434 (5)
H4A	0.3401	0.0353	0.7378	0.052*
H4B	0.2619	0.1334	0.7805	0.052*
C5	0.1881 (3)	0.12596 (13)	0.65264 (11)	0.0318 (4)
H5	0.0665	0.1697	0.6553	0.038*
C6	0.1518 (3)	0.04783 (12)	0.58217 (11)	0.0293 (4)
H6	0.2284	−0.0126	0.5967	0.035*
C7	−0.0736 (3)	0.02223 (12)	0.56617 (11)	0.0299 (4)
H7	−0.1476	0.0845	0.5557	0.036*
C8	−0.1172 (3)	−0.04621 (14)	0.48887 (12)	0.0379 (4)
C9	−0.3311 (4)	−0.08880 (16)	0.51157 (14)	0.0466 (5)
H9A	−0.4401	−0.0403	0.5022	0.056*
H9B	−0.3610	−0.1474	0.4779	0.056*
C10	−0.3114 (4)	−0.11414 (17)	0.60591 (14)	0.0514 (6)
H10A	−0.2413	−0.1772	0.6134	0.062*
H10B	−0.4476	−0.1178	0.6326	0.062*
C11	0.3685 (3)	0.18293 (14)	0.61722 (12)	0.0369 (4)
C12	0.3756 (3)	0.16406 (15)	0.52329 (12)	0.0387 (5)
O1	0.4807 (3)	0.20235 (13)	0.46923 (10)	0.0620 (5)
O2	−0.1301 (3)	0.00763 (13)	0.40985 (9)	0.0566 (5)
H2	−0.0522	0.0557	0.4118	0.085*
O3	0.2403 (2)	0.09088 (10)	0.50419 (7)	0.0362 (3)
O4	−0.1222 (3)	0.09798 (12)	0.79206 (10)	0.0573 (5)
H4	−0.2162	0.0730	0.8203	0.086*

	U11	U22	U33	U12	U13	U23
C13	0.0621 (16)	0.0839 (17)	0.0406 (11)	−0.0351 (15)	−0.0006 (12)	−0.0034 (12)
C14	0.0740 (17)	0.0480 (12)	0.0688 (16)	−0.0014 (13)	−0.0178 (15)	0.0204 (12)
C15	0.0588 (15)	0.0567 (13)	0.0685 (15)	−0.0020 (13)	0.0073 (13)	−0.0282 (13)
C1	0.0348 (10)	0.0377 (9)	0.0347 (9)	−0.0005 (8)	0.0039 (8)	0.0039 (7)
C2	0.0418 (11)	0.0429 (10)	0.0347 (9)	−0.0039 (9)	0.0016 (9)	0.0100 (8)
C3	0.0584 (13)	0.0511 (11)	0.0283 (8)	−0.0074 (11)	0.0002 (9)	0.0092 (8)
C4	0.0480 (12)	0.0531 (11)	0.0292 (9)	−0.0102 (10)	−0.0060 (9)	0.0037 (9)
C5	0.0326 (9)	0.0346 (8)	0.0283 (8)	−0.0027 (8)	−0.0017 (8)	0.0018 (7)
C6	0.0300 (9)	0.0315 (8)	0.0263 (8)	−0.0003 (7)	−0.0007 (7)	0.0036 (7)
C7	0.0325 (9)	0.0270 (8)	0.0301 (8)	0.0001 (7)	−0.0023 (7)	0.0016 (7)
C8	0.0394 (11)	0.0406 (10)	0.0338 (9)	−0.0087 (9)	−0.0016 (9)	−0.0016 (8)
C9	0.0423 (11)	0.0463 (11)	0.0511 (12)	−0.0115 (10)	−0.0062 (10)	−0.0023 (10)
C10	0.0473 (12)	0.0564 (12)	0.0505 (12)	−0.0189 (11)	−0.0014 (10)	0.0076 (10)
C11	0.0365 (11)	0.0393 (9)	0.0348 (9)	−0.0051 (8)	−0.0011 (8)	0.0024 (8)
C12	0.0385 (11)	0.0425 (10)	0.0350 (9)	−0.0077 (9)	0.0004 (9)	0.0033 (8)
O1	0.0665 (11)	0.0793 (12)	0.0403 (8)	−0.0341 (10)	0.0092 (8)	0.0057 (8)
O2	0.0708 (11)	0.0656 (10)	0.0333 (7)	−0.0277 (9)	−0.0134 (7)	0.0038 (7)
O3	0.0387 (7)	0.0427 (7)	0.0273 (6)	−0.0079 (6)	0.0026 (6)	0.0006 (5)
O4	0.0700 (11)	0.0567 (9)	0.0453 (8)	−0.0069 (9)	0.0244 (9)	−0.0022 (7)

C13—C11	1.314 (3)	C5—C11	1.497 (3)
C13—H13A	0.9300	C5—C6	1.542 (2)
C13—H13B	0.9300	C5—H5	0.9800
C14—C2	1.324 (3)	C6—O3	1.464 (2)
C14—H14A	0.9300	C6—C7	1.509 (3)
C14—H14B	0.9300	C6—H6	0.9800
C15—C8	1.523 (3)	C7—C8	1.546 (2)
C15—H15A	0.9600	C7—H7	0.9800
C15—H15B	0.9600	C8—O2	1.435 (2)
C15—H15C	0.9600	C8—C9	1.530 (3)
C1—C2	1.513 (3)	C9—C10	1.518 (3)
C1—C10	1.541 (3)	C9—H9A	0.9700
C1—C7	1.577 (2)	C9—H9B	0.9700
C1—H1	0.9800	C10—H10A	0.9700
C2—C3	1.534 (3)	C10—H10B	0.9700
C3—O4	1.423 (3)	C11—C12	1.490 (3)
C3—C4	1.523 (3)	C12—O1	1.198 (2)
C3—H3	0.9800	C12—O3	1.349 (2)
C4—C5	1.526 (2)	O2—H2	0.8200
C4—H4A	0.9700	O4—H4	0.8200
C4—H4B	0.9700
C11—C13—H13A	120.0	O3—C6—C7	109.01 (14)
C11—C13—H13B	120.0	O3—C6—C5	105.27 (13)
H13A—C13—H13B	120.0	C7—C6—C5	114.82 (15)
C2—C14—H14A	120.0	O3—C6—H6	109.2
C2—C14—H14B	120.0	C7—C6—H6	109.2
H14A—C14—H14B	120.0	C5—C6—H6	109.2
C8—C15—H15A	109.5	C6—C7—C8	116.10 (15)
C8—C15—H15B	109.5	C6—C7—C1	113.26 (15)
H15A—C15—H15B	109.5	C8—C7—C1	105.42 (14)
C8—C15—H15C	109.5	C6—C7—H7	107.2
H15A—C15—H15C	109.5	C8—C7—H7	107.2
H15B—C15—H15C	109.5	C1—C7—H7	107.2
C2—C1—C10	115.94 (17)	O2—C8—C15	107.27 (18)
C2—C1—C7	116.03 (16)	O2—C8—C9	109.74 (17)
C10—C1—C7	104.85 (15)	C15—C8—C9	111.66 (17)
C2—C1—H1	106.4	O2—C8—C7	112.29 (14)
C10—C1—H1	106.4	C15—C8—C7	113.96 (17)
C7—C1—H1	106.4	C9—C8—C7	101.90 (16)
C14—C2—C1	125.2 (2)	C10—C9—C8	103.59 (18)
C14—C2—C3	117.8 (2)	C10—C9—H9A	111.0
C1—C2—C3	117.04 (16)	C8—C9—H9A	111.0
O4—C3—C4	107.17 (17)	C10—C9—H9B	111.0
O4—C3—C2	112.13 (18)	C8—C9—H9B	111.0
C4—C3—C2	113.11 (17)	H9A—C9—H9B	109.0
O4—C3—H3	108.1	C9—C10—C1	105.22 (17)
C4—C3—H3	108.1	C9—C10—H10A	110.7
C2—C3—H3	108.1	C1—C10—H10A	110.7
C3—C4—C5	113.99 (17)	C9—C10—H10B	110.7
C3—C4—H4A	108.8	C1—C10—H10B	110.7
C5—C4—H4A	108.8	H10A—C10—H10B	108.8
C3—C4—H4B	108.8	C13—C11—C12	121.3 (2)
C5—C4—H4B	108.8	C13—C11—C5	131.25 (19)
H4A—C4—H4B	107.6	C12—C11—C5	107.44 (16)
C11—C5—C4	115.01 (16)	O1—C12—O3	121.53 (18)
C11—C5—C6	101.82 (14)	O1—C12—C11	129.6 (2)
C4—C5—C6	113.31 (15)	O3—C12—C11	108.86 (16)
C11—C5—H5	108.8	C8—O2—H2	109.5
C4—C5—H5	108.8	C12—O3—C6	110.91 (13)
C6—C5—H5	108.8	C3—O4—H4	109.5

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O3	0.82	2.42	3.015 (2)	131
O4—H4···O2i	0.82	2.03	2.819 (2)	162

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H2⋯O3	0.82	2.42	3.015 (2)	131
O4—H4⋯O2i	0.82	2.03	2.819 (2)	162

Symmetry code: (i) .