10α-Hy-droxy-4,9-dimethyl-13-(pipyridin-1-ylmethyl)-3,8,15-trioxatetra-cyclo-[10.3.0.0.0]tetra-decan-14-one.

The title compound, C(20)H(31)NO(5), was synthesized from 9α-hy-droxy-parthenolide (9α-hy-droxy-4,8-dimethyl-12-methylen-3,14-dioxa-tricyclo-[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 mol-ecule is built up from fused five-and ten-membered rings with the pipyridin-1-yl-methyl group as a substituent. The ten-membered ring adopts an approximate chair-chair conformation, while the six- and five-membered rings display chair and envelope conformations, respectively. The dihedral angle between the mean planes of the ten-membered ring and the lactone ring is 20.8 (3)°. An intra-molecular O-H⋯N hydrogen-bond occurs. The crystal structure is stabilized by weak inter-molecular C-H⋯O hydrogen bonds.

Related literature

For background to the medicinal uses of the plant Anvillea radiata, see: El Hassany et al. (2004 ▶); Qureshi et al. (1990 ▶). For the reactivity of this sesquiterpene, see: Hwang et al. (2006 ▶); Neukirch et al. (2003 ▶); Neelakantan et al. (2009 ▶); Moumou et al. (2010 ▶). For ring puckering parameters, see: Cremer & Pople (1975 ▶). For conformations of ten-membered rings, see: Castaneda-Acosta et al. (1997 ▶); Watson & Zabel (1982 ▶).

Experimental

Crystal data

C20H31NO5

M = 365.46

Orthorhombic,

a = 8.0899 (5) Å

b = 10.7562 (6) Å

c = 22.5093 (13) Å

V = 1958.7 (2) Å3

Z = 4

Mo Kα radiation

μ = 0.09 mm−1

T = 296 K

0.85 × 0.48 × 0.36 mm

Data collection

Bruker X8 APEX CCD area-detector diffractometer

8978 measured reflections

2291 independent reflections

1707 reflections with I > 2σ(I)

R int = 0.036

Refinement

R[F 2 > 2σ(F 2)] = 0.036

wR(F 2) = 0.087

S = 1.07

2291 reflections

239 parameters

H-atom parameters constrained

Δρmax = 0.16 e Å−3

Δρmin = −0.16 e Å−3

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: 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 publication routines (Farrugia, 1999 ▶).

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536811042644/fj2458sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811042644/fj2458Isup2.hkl

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

C20H31NO5	F(000) = 792
Mr = 365.46	Dx = 1.236 Mg m−3
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 8987 reflections
a = 8.0899 (5) Å	θ = 2.6–26.4°
b = 10.7562 (6) Å	µ = 0.09 mm−1
c = 22.5093 (13) Å	T = 296 K
V = 1958.7 (2) Å3	Prism, colourless
Z = 4	0.85 × 0.48 × 0.36 mm

Bruker X8 APEX CCD area-detector diffractometer	1707 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.036
graphite	θmax = 26.4°, θmin = 3.3°
φ and ω scans	h = −10→6
8978 measured reflections	k = −13→13
2291 independent reflections	l = −21→28

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)] = 0.036	H-atom parameters constrained
wR(F2) = 0.087	w = 1/[σ2(Fo2) + (0.0377P)2 + 0.1661P] where P = (Fo2 + 2Fc2)/3
S = 1.07	(Δ/σ)max < 0.001
2291 reflections	Δρmax = 0.16 e Å−3
239 parameters	Δρmin = −0.16 e Å−3
0 restraints	Extinction correction: SHELXL, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.035 (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
C1	−0.2580 (3)	0.4198 (2)	−0.04973 (10)	0.0372 (6)
H1	−0.2042	0.3507	−0.0705	0.045*
C2	−0.2861 (3)	0.5264 (2)	−0.09033 (10)	0.0368 (6)
H2	−0.3339	0.5994	−0.0707	0.044*
C3	−0.1874 (3)	0.5566 (2)	−0.14313 (10)	0.0413 (6)
C4	−0.1764 (4)	0.6933 (2)	−0.15778 (11)	0.0512 (7)
H4A	−0.2786	0.7333	−0.1459	0.061*
H4B	−0.1655	0.7026	−0.2005	0.061*
C5	−0.0314 (4)	0.7599 (2)	−0.12752 (11)	0.0521 (7)
H5A	0.0689	0.7426	−0.1497	0.062*
H5B	−0.0505	0.8488	−0.1291	0.062*
C6	−0.0053 (3)	0.7223 (2)	−0.06357 (10)	0.0395 (6)
H6	−0.1072	0.7104	−0.0408	0.047*
C7	0.1382 (3)	0.6516 (2)	−0.04136 (10)	0.0389 (6)
C8	0.1253 (3)	0.5682 (2)	0.01315 (10)	0.0383 (6)
H8	0.2380	0.5444	0.0245	0.046*
C9	0.0296 (3)	0.4476 (2)	−0.00041 (10)	0.0360 (5)
H9A	0.0557	0.4216	−0.0406	0.043*
H9B	0.0682	0.3830	0.0263	0.043*
C10	−0.1594 (3)	0.45804 (19)	0.00554 (9)	0.0336 (5)
H10	−0.1854	0.5453	0.0138	0.040*
C11	−0.2408 (3)	0.3801 (2)	0.05391 (10)	0.0402 (6)
H11	−0.1878	0.2981	0.0548	0.048*
C12	−0.4147 (3)	0.3652 (2)	0.03188 (12)	0.0475 (7)
C13	−0.2395 (4)	0.4343 (2)	0.11655 (11)	0.0496 (7)
H13A	−0.2902	0.5160	0.1155	0.060*
H13B	−0.3068	0.3821	0.1420	0.060*
C14	−0.0526 (4)	0.4736 (3)	−0.16635 (11)	0.0553 (7)
H14A	−0.0692	0.3906	−0.1518	0.083*
H14B	0.0527	0.5039	−0.1531	0.083*
H14C	−0.0554	0.4732	−0.2090	0.083*
C15	0.2820 (3)	0.6167 (3)	−0.08001 (12)	0.0577 (8)
H15A	0.2761	0.6619	−0.1167	0.087*
H15B	0.2787	0.5291	−0.0881	0.087*
H15C	0.3833	0.6368	−0.0600	0.087*
C16	−0.0852 (4)	0.5186 (2)	0.19775 (11)	0.0609 (8)
H16A	−0.1613	0.4786	0.2250	0.073*
H16B	−0.1281	0.6007	0.1888	0.073*
C17	−0.0073 (4)	0.3219 (2)	0.15623 (12)	0.0555 (7)
H17A	−0.0010	0.2739	0.1198	0.067*
H17B	−0.0819	0.2791	0.1830	0.067*
C18	0.0815 (5)	0.5311 (3)	0.22704 (13)	0.0763 (11)
H18A	0.0696	0.5773	0.2638	0.092*
H18B	0.1548	0.5776	0.2012	0.092*
C19	0.1611 (4)	0.3277 (3)	0.18398 (13)	0.0736 (10)
H19A	0.2387	0.3637	0.1560	0.088*
H19B	0.1983	0.2443	0.1934	0.088*
C20	0.1572 (5)	0.4055 (3)	0.24020 (13)	0.0764 (10)
H20A	0.0927	0.3633	0.2704	0.092*
H20B	0.2687	0.4164	0.2552	0.092*
N1	−0.0753 (3)	0.44545 (17)	0.14266 (8)	0.0434 (5)
O1	0.0559 (2)	0.63372 (15)	0.06146 (7)	0.0471 (5)
H21	0.0226	0.5841	0.0864	0.071*
O2	−0.4209 (2)	0.38309 (15)	−0.02731 (8)	0.0470 (5)
O3	−0.3509 (2)	0.50418 (16)	−0.14908 (7)	0.0496 (5)
O4	0.1255 (2)	0.78432 (15)	−0.03166 (7)	0.0490 (5)
O5	−0.5382 (3)	0.34028 (19)	0.05929 (9)	0.0674 (6)

	U11	U22	U33	U12	U13	U23
C1	0.0344 (13)	0.0347 (11)	0.0426 (13)	−0.0018 (11)	−0.0010 (11)	−0.0057 (10)
C2	0.0345 (14)	0.0383 (12)	0.0375 (12)	−0.0001 (11)	−0.0080 (10)	−0.0038 (10)
C3	0.0428 (15)	0.0471 (13)	0.0340 (12)	−0.0030 (13)	−0.0071 (11)	−0.0045 (11)
C4	0.0597 (18)	0.0551 (15)	0.0389 (14)	−0.0029 (15)	−0.0084 (13)	0.0070 (12)
C5	0.0610 (18)	0.0456 (14)	0.0496 (15)	−0.0062 (14)	−0.0019 (14)	0.0091 (12)
C6	0.0409 (14)	0.0355 (11)	0.0420 (13)	−0.0074 (12)	−0.0008 (11)	−0.0004 (10)
C7	0.0333 (13)	0.0410 (12)	0.0425 (13)	−0.0068 (12)	−0.0001 (11)	−0.0077 (11)
C8	0.0322 (13)	0.0428 (12)	0.0399 (12)	0.0027 (12)	−0.0059 (10)	−0.0066 (11)
C9	0.0378 (13)	0.0321 (11)	0.0382 (12)	0.0045 (11)	−0.0044 (11)	−0.0013 (10)
C10	0.0364 (13)	0.0266 (10)	0.0378 (12)	0.0022 (11)	−0.0010 (10)	−0.0032 (10)
C11	0.0468 (16)	0.0319 (11)	0.0421 (13)	0.0018 (12)	0.0052 (12)	0.0025 (10)
C12	0.0490 (17)	0.0343 (12)	0.0592 (17)	−0.0048 (13)	0.0064 (15)	0.0018 (12)
C13	0.0587 (18)	0.0461 (13)	0.0440 (14)	0.0098 (15)	0.0126 (13)	0.0034 (12)
C14	0.0554 (18)	0.0632 (16)	0.0472 (15)	−0.0023 (16)	0.0081 (13)	−0.0105 (13)
C15	0.0395 (16)	0.0745 (18)	0.0592 (17)	−0.0019 (16)	0.0072 (13)	−0.0018 (15)
C16	0.101 (3)	0.0442 (14)	0.0379 (14)	0.0050 (17)	0.0115 (16)	−0.0063 (12)
C17	0.074 (2)	0.0468 (14)	0.0460 (14)	0.0131 (15)	−0.0078 (15)	−0.0031 (13)
C18	0.116 (3)	0.070 (2)	0.0428 (15)	−0.024 (2)	0.0013 (19)	−0.0148 (15)
C19	0.081 (2)	0.084 (2)	0.0565 (18)	0.019 (2)	−0.0138 (18)	−0.0114 (16)
C20	0.086 (2)	0.091 (2)	0.0522 (18)	−0.001 (2)	−0.0110 (17)	−0.0086 (16)
N1	0.0642 (15)	0.0354 (10)	0.0305 (10)	0.0038 (11)	0.0050 (10)	−0.0030 (9)
O1	0.0609 (12)	0.0430 (9)	0.0374 (9)	−0.0072 (10)	0.0007 (9)	−0.0079 (7)
O2	0.0399 (10)	0.0453 (9)	0.0558 (11)	−0.0112 (9)	−0.0041 (9)	0.0024 (8)
O3	0.0468 (11)	0.0607 (11)	0.0414 (9)	−0.0071 (10)	−0.0148 (8)	−0.0030 (8)
O4	0.0540 (11)	0.0392 (8)	0.0538 (10)	−0.0127 (9)	−0.0059 (9)	−0.0042 (8)
O5	0.0545 (13)	0.0677 (12)	0.0801 (14)	−0.0161 (11)	0.0205 (12)	0.0067 (11)

C1—O2	1.465 (3)	C11—C13	1.526 (3)
C1—C2	1.484 (3)	C11—H11	0.9800
C1—C10	1.534 (3)	C12—O5	1.204 (3)
C1—H1	0.9800	C12—O2	1.347 (3)
C2—O3	1.442 (3)	C13—N1	1.457 (3)
C2—C3	1.468 (3)	C13—H13A	0.9700
C2—H2	0.9800	C13—H13B	0.9700
C3—O3	1.445 (3)	C14—H14A	0.9600
C3—C14	1.503 (4)	C14—H14B	0.9600
C3—C4	1.509 (3)	C14—H14C	0.9600
C4—C5	1.534 (4)	C15—H15A	0.9600
C4—H4A	0.9700	C15—H15B	0.9600
C4—H4B	0.9700	C15—H15C	0.9600
C5—C6	1.510 (3)	C16—N1	1.471 (3)
C5—H5A	0.9700	C16—C18	1.507 (5)
C5—H5B	0.9700	C16—H16A	0.9700
C6—O4	1.442 (3)	C16—H16B	0.9700
C6—C7	1.475 (3)	C17—N1	1.470 (3)
C6—H6	0.9800	C17—C19	1.500 (4)
C7—O4	1.448 (3)	C17—H17A	0.9700
C7—C15	1.500 (3)	C17—H17B	0.9700
C7—C8	1.524 (3)	C18—C20	1.512 (5)
C8—O1	1.413 (3)	C18—H18A	0.9700
C8—C9	1.541 (3)	C18—H18B	0.9700
C8—H8	0.9800	C19—C20	1.518 (4)
C9—C10	1.540 (3)	C19—H19A	0.9700
C9—H9A	0.9700	C19—H19B	0.9700
C9—H9B	0.9700	C20—H20A	0.9700
C10—C11	1.524 (3)	C20—H20B	0.9700
C10—H10	0.9800	O1—H21	0.8200
C11—C12	1.501 (4)
O2—C1—C2	106.41 (19)	C10—C11—C13	116.5 (2)
O2—C1—C10	105.09 (17)	C12—C11—H11	108.7
C2—C1—C10	111.82 (18)	C10—C11—H11	108.7
O2—C1—H1	111.1	C13—C11—H11	108.7
C2—C1—H1	111.1	O5—C12—O2	120.5 (3)
C10—C1—H1	111.1	O5—C12—C11	129.2 (3)
O3—C2—C3	59.51 (14)	O2—C12—C11	110.3 (2)
O3—C2—C1	119.48 (19)	N1—C13—C11	114.2 (2)
C3—C2—C1	125.9 (2)	N1—C13—H13A	108.7
O3—C2—H2	113.7	C11—C13—H13A	108.7
C3—C2—H2	113.7	N1—C13—H13B	108.7
C1—C2—H2	113.7	C11—C13—H13B	108.7
O3—C3—C2	59.36 (15)	H13A—C13—H13B	107.6
O3—C3—C14	113.6 (2)	C3—C14—H14A	109.5
C2—C3—C14	123.0 (2)	C3—C14—H14B	109.5
O3—C3—C4	114.5 (2)	H14A—C14—H14B	109.5
C2—C3—C4	115.1 (2)	C3—C14—H14C	109.5
C14—C3—C4	117.4 (2)	H14A—C14—H14C	109.5
C3—C4—C5	113.8 (2)	H14B—C14—H14C	109.5
C3—C4—H4A	108.8	C7—C15—H15A	109.5
C5—C4—H4A	108.8	C7—C15—H15B	109.5
C3—C4—H4B	108.8	H15A—C15—H15B	109.5
C5—C4—H4B	108.8	C7—C15—H15C	109.5
H4A—C4—H4B	107.7	H15A—C15—H15C	109.5
C6—C5—C4	113.9 (2)	H15B—C15—H15C	109.5
C6—C5—H5A	108.8	N1—C16—C18	111.6 (2)
C4—C5—H5A	108.8	N1—C16—H16A	109.3
C6—C5—H5B	108.8	C18—C16—H16A	109.3
C4—C5—H5B	108.8	N1—C16—H16B	109.3
H5A—C5—H5B	107.7	C18—C16—H16B	109.3
O4—C6—C7	59.51 (14)	H16A—C16—H16B	108.0
O4—C6—C5	117.0 (2)	N1—C17—C19	112.9 (2)
C7—C6—C5	124.8 (2)	N1—C17—H17A	109.0
O4—C6—H6	114.6	C19—C17—H17A	109.0
C7—C6—H6	114.6	N1—C17—H17B	109.0
C5—C6—H6	114.6	C19—C17—H17B	109.0
O4—C7—C6	59.12 (14)	H17A—C17—H17B	107.8
O4—C7—C15	112.9 (2)	C16—C18—C20	111.6 (3)
C6—C7—C15	122.9 (2)	C16—C18—H18A	109.3
O4—C7—C8	117.02 (18)	C20—C18—H18A	109.3
C6—C7—C8	121.5 (2)	C16—C18—H18B	109.3
C15—C7—C8	111.9 (2)	C20—C18—H18B	109.3
O1—C8—C7	110.69 (18)	H18A—C18—H18B	108.0
O1—C8—C9	111.89 (19)	C17—C19—C20	110.6 (3)
C7—C8—C9	111.75 (18)	C17—C19—H19A	109.5
O1—C8—H8	107.4	C20—C19—H19A	109.5
C7—C8—H8	107.4	C17—C19—H19B	109.5
C9—C8—H8	107.4	C20—C19—H19B	109.5
C10—C9—C8	114.86 (18)	H19A—C19—H19B	108.1
C10—C9—H9A	108.6	C18—C20—C19	109.7 (2)
C8—C9—H9A	108.6	C18—C20—H20A	109.7
C10—C9—H9B	108.6	C19—C20—H20A	109.7
C8—C9—H9B	108.6	C18—C20—H20B	109.7
H9A—C9—H9B	107.5	C19—C20—H20B	109.7
C11—C10—C1	101.97 (17)	H20A—C20—H20B	108.2
C11—C10—C9	116.8 (2)	C13—N1—C17	110.5 (2)
C1—C10—C9	115.23 (19)	C13—N1—C16	109.5 (2)
C11—C10—H10	107.4	C17—N1—C16	109.18 (19)
C1—C10—H10	107.4	C8—O1—H21	109.5
C9—C10—H10	107.4	C12—O2—C1	110.24 (19)
C12—C11—C10	103.16 (19)	C2—O3—C3	61.13 (14)
C12—C11—C13	110.6 (2)	C6—O4—C7	61.38 (15)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H21···N1	0.82	2.11	2.927 (2)	174
C1—H1···O5i	0.98	2.47	3.322 (3)	146
C10—H10···O4ii	0.98	2.42	3.325 (3)	153

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H21⋯N1	0.82	2.11	2.927 (2)	174
C1—H1⋯O5i	0.98	2.47	3.322 (3)	146
C10—H10⋯O4ii	0.98	2.42	3.325 (3)	153

Symmetry codes: (i) ; (ii) .