(3R,4S,5S,8S,10R,13R)-3-Hy-droxy-kaura-9(11),16-dien-18-oic acid.

The title compound, C(20)H(28)O(3), was isolated during our investigation into the chemical composition and pharmacological activity of Centipeda cunninghamii (DC.) A. Braun & Asch. (Asteraceae). The enanti-opure compound, a diterpene with a carbon skeleton, is composed of three six- and one five-membered rings in chair, twist-boat, half-chair and envelope conformations, respectively. Each mol-ecule makes one intra- and one inter-molecular O-H⋯O hydrogen bond in the crystal lattice, forming hydrogen-bonded chains along [010]. The absolute configuration of the compound was assigned on the basis of optical rotation measurements.

Related literature

For the characterization of related kaurane diterpenes, see: Reynolds et al. (1991 ▶); Piozzi et al. (1972 ▶). For literature on the occurrence of the 3S isomer of the title compound isolated from Ichthyothere terminalis and Pseudognaphalium cheiranthifolium, see: Bohlmann et al. (1982 ▶); Mendoza & Urzúa (1998 ▶). For the anti­bacterial activity of the 3S isomer, see: Mendoza et al. (1997 ▶). For phytopharmacological aspects of Centipeda cunninghamii, see: Campbell (1973 ▶); Cribb (1988 ▶); D’Amelio & Mirhom, (1998 ▶); Maiden (1975 ▶); Webb (1948 ▶). For optical rotation data of related compounds, see: Bohlmann et al. (1982 ▶); Brieskorn & Pöhlmann (1968 ▶); Reynolds et al. (1991 ▶).

Experimental

Crystal data

C20H28O3

M = 316.4

Monoclinic,

a = 8.064 (2) Å

b = 10.775 (3) Å

c = 10.462 (4) Å

β = 109.70 (2)°

V = 855.8 (5) Å3

Z = 2

Mo Kα radiation

μ = 0.08 mm−1

T = 296 K

0.30 × 0.25 × 0.10 mm

Data collection

Enraf–Nonius CAD-4 diffractometer

1586 measured reflections

1586 independent reflections

1254 reflections with I > 2σ(I)

R int = 0.000

1 standard reflections every 30 min intensity decay: none

Refinement

R[F 2 > 2σ(F 2)] = 0.044

wR(F 2) = 0.112

S = 1.05

1586 reflections

218 parameters

1 restraint

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.15 e Å−3

Δρmin = −0.17 e Å−3

Data collection: CAD-4 Software (Enraf–Nonius, 1989 ▶); cell refinement: CAD-4 Software; data reduction: CAD-4 Software; 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 Mercury (Macrae et al., 2008 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812002206/qk2025sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812002206/qk2025Isup2.hkl

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

C20H28O3	F(000) = 344
Mr = 316.4	Dx = 1.228 Mg m−3
Monoclinic, P21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2yb	Cell parameters from 11 reflections
a = 8.064 (2) Å	θ = 10–11°
b = 10.775 (3) Å	µ = 0.08 mm−1
c = 10.462 (4) Å	T = 296 K
β = 109.70 (2)°	Block, colourless
V = 855.8 (5) Å3	0.30 × 0.25 × 0.10 mm
Z = 2

Enraf–Nonius CAD-4 diffractometer	Rint = 0.0000
Radiation source: fine-focus sealed tube	θmax = 25.0°, θmin = 2.1°
graphite	h = −9→9
ω–2θ scans	k = 0→12
1586 measured reflections	l = 0→12
1586 independent reflections	1 standard reflections every 30 min
1254 reflections with I > 2σ(I)	intensity decay: none

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)] = 0.044	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.112	w = 1/[σ2(Fo2) + (0.0704P)2] where P = (Fo2 + 2Fc2)/3
S = 1.05	(Δ/σ)max = 0.001
1586 reflections	Δρmax = 0.15 e Å−3
218 parameters	Δρmin = −0.17 e Å−3
1 restraint	Absolute structure: deduced from optical rotation
Primary atom site location: structure-invariant direct methods

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	0.3554 (4)	0.4597 (3)	0.9863 (3)	0.0658 (8)
O2	0.4220 (4)	0.2189 (3)	0.9850 (2)	0.0620 (7)
O3	0.5758 (4)	0.1598 (3)	0.8595 (3)	0.0678 (9)
C1	0.0447 (4)	0.3543 (4)	0.6459 (4)	0.0521 (10)
C2	0.1154 (5)	0.3753 (4)	0.7994 (4)	0.0511 (9)
C3	0.2956 (5)	0.4335 (3)	0.8438 (3)	0.0473 (9)
C4	0.4293 (4)	0.3558 (3)	0.8032 (3)	0.0395 (8)
C5	0.3551 (4)	0.3369 (3)	0.6461 (3)	0.0359 (7)
C6	0.4877 (5)	0.2789 (4)	0.5853 (3)	0.0520 (9)
C7	0.4047 (5)	0.2222 (4)	0.4458 (3)	0.0572 (10)
C8	0.2344 (4)	0.2860 (4)	0.3602 (3)	0.0460 (8)
C9	0.1005 (4)	0.2857 (3)	0.4348 (3)	0.0435 (8)
C10	0.1677 (4)	0.2779 (3)	0.5907 (3)	0.0399 (8)
C11	−0.0703 (5)	0.2924 (4)	0.3625 (4)	0.0587 (10)
C12	−0.1416 (5)	0.3019 (4)	0.2107 (4)	0.0667 (12)
C13	0.0059 (6)	0.3158 (4)	0.1511 (4)	0.0609 (11)
C14	0.1503 (6)	0.2238 (4)	0.2209 (4)	0.0645 (11)
C15	0.2579 (5)	0.4187 (4)	0.3156 (3)	0.0499 (9)
C16	0.0971 (5)	0.4395 (4)	0.1910 (3)	0.0485 (9)
C17	0.0429 (5)	0.5449 (4)	0.1297 (4)	0.0567 (10)
C18	0.4701 (4)	0.2379 (3)	0.8902 (3)	0.0422 (8)
C19	0.6049 (5)	0.4288 (4)	0.8399 (4)	0.0578 (10)
C20	0.1658 (5)	0.1410 (4)	0.6329 (4)	0.0518 (9)
H1A	0.0241	0.4344	0.6009	0.062*
H1B	−0.0679	0.3121	0.6225	0.062*
H1O1	0.353 (7)	0.381 (6)	1.029 (6)	0.11 (2)*
H1O3	0.598 (6)	0.104 (5)	0.916 (5)	0.070 (14)*
H2A	0.0352	0.4289	0.8251	0.061*
H2B	0.1212	0.2965	0.8455	0.061*
H3A	0.2844	0.5133	0.7966	0.057*
H5	0.3378	0.4215	0.6096	0.043*
H6A	0.5700	0.3427	0.5799	0.062*
H6B	0.5545	0.2152	0.6467	0.062*
H7A	0.3802	0.1353	0.4561	0.069*
H7B	0.4886	0.2262	0.3977	0.069*
H11	−0.1504	0.2912	0.4089	0.070*
H12A	−0.2197	0.3730	0.1847	0.080*
H12B	−0.2097	0.2281	0.1736	0.080*
H13	−0.0373	0.3044	0.0524	0.073*
H14A	0.2340	0.2154	0.1732	0.077*
H14B	0.1024	0.1429	0.2294	0.077*
H15A	0.2618	0.4781	0.3863	0.060*
H15B	0.3652	0.4260	0.2937	0.060*
H17A	−0.0600	0.5480	0.0549	0.068*
H17B	0.1071	0.6171	0.1610	0.068*
H19A	0.6417	0.4530	0.9336	0.087*
H19B	0.5881	0.5014	0.7839	0.087*
H19C	0.6936	0.3771	0.8250	0.087*
H20A	0.0491	0.1080	0.5929	0.078*
H20B	0.2006	0.1356	0.7300	0.078*
H20C	0.2464	0.0942	0.6021	0.078*

	U11	U22	U33	U12	U13	U23
O1	0.094 (2)	0.0543 (18)	0.0541 (17)	−0.0171 (15)	0.0310 (15)	−0.0191 (14)
O2	0.0852 (18)	0.0558 (16)	0.0539 (14)	0.0077 (16)	0.0353 (14)	0.0151 (14)
O3	0.0799 (19)	0.0664 (19)	0.0635 (19)	0.0311 (16)	0.0324 (16)	0.0300 (16)
C1	0.0394 (19)	0.061 (2)	0.054 (2)	0.0037 (18)	0.0125 (16)	0.0050 (19)
C2	0.053 (2)	0.046 (2)	0.060 (2)	0.0081 (18)	0.0275 (18)	−0.0023 (18)
C3	0.067 (2)	0.0321 (18)	0.047 (2)	−0.0034 (17)	0.0240 (17)	−0.0033 (16)
C4	0.0405 (18)	0.0345 (18)	0.0401 (18)	−0.0065 (15)	0.0094 (14)	−0.0001 (15)
C5	0.0370 (16)	0.0337 (16)	0.0352 (16)	0.0009 (14)	0.0100 (13)	0.0038 (14)
C6	0.0451 (18)	0.066 (2)	0.0468 (19)	0.0127 (19)	0.0179 (16)	0.0072 (19)
C7	0.070 (2)	0.056 (2)	0.052 (2)	0.020 (2)	0.0293 (18)	0.008 (2)
C8	0.055 (2)	0.0439 (19)	0.0368 (17)	0.0057 (18)	0.0120 (15)	0.0002 (16)
C9	0.053 (2)	0.0355 (16)	0.0396 (17)	−0.0086 (17)	0.0127 (15)	−0.0014 (15)
C10	0.0408 (18)	0.0368 (18)	0.0406 (18)	−0.0055 (16)	0.0119 (15)	−0.0012 (15)
C11	0.052 (2)	0.065 (2)	0.051 (2)	−0.020 (2)	0.0080 (18)	0.004 (2)
C12	0.063 (2)	0.070 (3)	0.048 (2)	−0.025 (2)	−0.0063 (19)	0.004 (2)
C13	0.085 (3)	0.054 (3)	0.0337 (18)	0.001 (2)	0.0073 (19)	−0.0051 (16)
C14	0.095 (3)	0.047 (2)	0.047 (2)	0.007 (2)	0.019 (2)	−0.0020 (19)
C15	0.052 (2)	0.055 (2)	0.0442 (19)	−0.0005 (18)	0.0193 (16)	0.0042 (18)
C16	0.059 (2)	0.049 (2)	0.0421 (19)	0.0009 (18)	0.0233 (16)	0.0043 (17)
C17	0.049 (2)	0.058 (2)	0.065 (2)	0.0036 (19)	0.0203 (17)	0.009 (2)
C18	0.0398 (17)	0.0418 (18)	0.0397 (17)	−0.0048 (16)	0.0061 (15)	−0.0008 (16)
C19	0.052 (2)	0.057 (2)	0.058 (2)	−0.017 (2)	0.0090 (18)	0.0025 (19)
C20	0.064 (2)	0.042 (2)	0.046 (2)	−0.0102 (18)	0.0138 (17)	−0.0012 (17)

O1—C3	1.432 (4)	C8—C15	1.536 (5)
O1—H1O1	0.96 (7)	C8—C14	1.538 (5)
O2—C18	1.198 (4)	C9—C11	1.331 (5)
O3—C18	1.312 (4)	C9—C10	1.537 (4)
O3—H1O3	0.82 (5)	C10—C20	1.541 (5)
C1—C2	1.529 (5)	C11—C12	1.499 (5)
C1—C10	1.544 (5)	C11—H11	0.9300
C1—H1A	0.9700	C12—C13	1.525 (6)
C1—H1B	0.9700	C12—H12A	0.9700
C2—C3	1.505 (5)	C12—H12B	0.9700
C2—H2A	0.9700	C13—C16	1.511 (6)
C2—H2B	0.9700	C13—C14	1.516 (6)
C3—C4	1.534 (5)	C13—H13	0.9800
C3—H3A	0.9800	C14—H14A	0.9700
C4—C18	1.532 (5)	C14—H14B	0.9700
C4—C19	1.551 (5)	C15—C16	1.514 (5)
C4—C5	1.562 (4)	C15—H15A	0.9700
C5—C6	1.549 (5)	C15—H15B	0.9700
C5—C10	1.559 (4)	C16—C17	1.305 (6)
C5—H5	0.9800	C17—H17A	0.9300
C6—C7	1.514 (5)	C17—H17B	0.9300
C6—H6A	0.9700	C19—H19A	0.9600
C6—H6B	0.9700	C19—H19B	0.9600
C7—C8	1.527 (5)	C19—H19C	0.9600
C7—H7A	0.9700	C20—H20A	0.9600
C7—H7B	0.9700	C20—H20B	0.9600
C8—C9	1.531 (5)	C20—H20C	0.9600
C3—O1—H1O1	105 (4)	C9—C10—C1	109.0 (3)
C18—O3—H1O3	107 (3)	C20—C10—C1	109.5 (3)
C2—C1—C10	114.4 (3)	C9—C10—C5	108.8 (2)
C2—C1—H1A	108.7	C20—C10—C5	112.7 (3)
C10—C1—H1A	108.7	C1—C10—C5	107.9 (3)
C2—C1—H1B	108.7	C9—C11—C12	124.1 (4)
C10—C1—H1B	108.7	C9—C11—H11	118.0
H1A—C1—H1B	107.6	C12—C11—H11	118.0
C3—C2—C1	111.4 (3)	C11—C12—C13	111.5 (3)
C3—C2—H2A	109.3	C11—C12—H12A	109.3
C1—C2—H2A	109.3	C13—C12—H12A	109.3
C3—C2—H2B	109.3	C11—C12—H12B	109.3
C1—C2—H2B	109.3	C13—C12—H12B	109.3
H2A—C2—H2B	108.0	H12A—C12—H12B	108.0
O1—C3—C2	110.8 (3)	C16—C13—C14	102.7 (3)
O1—C3—C4	112.0 (3)	C16—C13—C12	110.4 (3)
C2—C3—C4	112.5 (3)	C14—C13—C12	108.5 (3)
O1—C3—H3A	107.1	C16—C13—H13	111.6
C2—C3—H3A	107.1	C14—C13—H13	111.6
C4—C3—H3A	107.1	C12—C13—H13	111.6
C18—C4—C3	108.6 (3)	C13—C14—C8	101.2 (3)
C18—C4—C19	106.2 (3)	C13—C14—H14A	111.5
C3—C4—C19	108.8 (3)	C8—C14—H14A	111.5
C18—C4—C5	116.5 (3)	C13—C14—H14B	111.5
C3—C4—C5	107.9 (3)	C8—C14—H14B	111.5
C19—C4—C5	108.7 (3)	H14A—C14—H14B	109.4
C6—C5—C10	113.6 (3)	C16—C15—C8	104.0 (3)
C6—C5—C4	114.4 (3)	C16—C15—H15A	111.0
C10—C5—C4	115.1 (2)	C8—C15—H15A	111.0
C6—C5—H5	104.0	C16—C15—H15B	111.0
C10—C5—H5	104.0	C8—C15—H15B	111.0
C4—C5—H5	104.0	H15A—C15—H15B	109.0
C7—C6—C5	114.6 (3)	C17—C16—C13	125.5 (3)
C7—C6—H6A	108.6	C17—C16—C15	126.8 (4)
C5—C6—H6A	108.6	C13—C16—C15	107.7 (3)
C7—C6—H6B	108.6	C16—C17—H17A	120.0
C5—C6—H6B	108.6	C16—C17—H17B	120.0
H6A—C6—H6B	107.6	H17A—C17—H17B	120.0
C6—C7—C8	113.7 (3)	O2—C18—O3	120.7 (3)
C6—C7—H7A	108.8	O2—C18—C4	124.7 (3)
C8—C7—H7A	108.8	O3—C18—C4	114.4 (3)
C6—C7—H7B	108.8	C4—C19—H19A	109.5
C8—C7—H7B	108.8	C4—C19—H19B	109.5
H7A—C7—H7B	107.7	H19A—C19—H19B	109.5
C7—C8—C9	110.5 (3)	C4—C19—H19C	109.5
C7—C8—C15	114.8 (3)	H19A—C19—H19C	109.5
C9—C8—C15	109.7 (3)	H19B—C19—H19C	109.5
C7—C8—C14	112.5 (3)	C10—C20—H20A	109.5
C9—C8—C14	108.7 (3)	C10—C20—H20B	109.5
C15—C8—C14	100.2 (3)	H20A—C20—H20B	109.5
C11—C9—C8	118.8 (3)	C10—C20—H20C	109.5
C11—C9—C10	122.3 (3)	H20A—C20—H20C	109.5
C8—C9—C10	118.9 (3)	H20B—C20—H20C	109.5
C9—C10—C20	108.8 (3)
C10—C1—C2—C3	54.8 (4)	C2—C1—C10—C20	72.3 (4)
C1—C2—C3—O1	176.4 (3)	C2—C1—C10—C5	−50.7 (4)
C1—C2—C3—C4	−57.4 (4)	C6—C5—C10—C9	−55.0 (4)
O1—C3—C4—C18	55.0 (3)	C4—C5—C10—C9	170.5 (3)
C2—C3—C4—C18	−70.5 (3)	C6—C5—C10—C20	65.7 (4)
O1—C3—C4—C19	−60.1 (4)	C4—C5—C10—C20	−68.7 (3)
C2—C3—C4—C19	174.4 (3)	C6—C5—C10—C1	−173.2 (3)
O1—C3—C4—C5	−177.9 (3)	C4—C5—C10—C1	52.3 (4)
C2—C3—C4—C5	56.6 (3)	C8—C9—C11—C12	−0.8 (6)
C18—C4—C5—C6	−67.3 (4)	C10—C9—C11—C12	179.1 (4)
C3—C4—C5—C6	170.3 (3)	C9—C11—C12—C13	−5.6 (6)
C19—C4—C5—C6	52.5 (4)	C11—C12—C13—C16	−67.3 (5)
C18—C4—C5—C10	66.8 (4)	C11—C12—C13—C14	44.5 (5)
C3—C4—C5—C10	−55.6 (3)	C16—C13—C14—C8	42.4 (4)
C19—C4—C5—C10	−173.4 (3)	C12—C13—C14—C8	−74.4 (4)
C10—C5—C6—C7	26.2 (5)	C7—C8—C14—C13	−171.1 (3)
C4—C5—C6—C7	161.1 (3)	C9—C8—C14—C13	66.3 (4)
C5—C6—C7—C8	30.5 (5)	C15—C8—C14—C13	−48.7 (4)
C6—C7—C8—C9	−56.6 (4)	C7—C8—C15—C16	156.9 (3)
C6—C7—C8—C15	68.0 (4)	C9—C8—C15—C16	−78.1 (3)
C6—C7—C8—C14	−178.2 (3)	C14—C8—C15—C16	36.2 (3)
C7—C8—C9—C11	−154.9 (4)	C14—C13—C16—C17	161.6 (4)
C15—C8—C9—C11	77.6 (4)	C12—C13—C16—C17	−82.9 (5)
C14—C8—C9—C11	−31.1 (5)	C14—C13—C16—C15	−19.9 (4)
C7—C8—C9—C10	25.3 (4)	C12—C13—C16—C15	95.6 (4)
C15—C8—C9—C10	−102.2 (3)	C8—C15—C16—C17	167.9 (3)
C14—C8—C9—C10	149.1 (3)	C8—C15—C16—C13	−10.5 (4)
C11—C9—C10—C20	85.3 (5)	C3—C4—C18—O2	−8.6 (4)
C8—C9—C10—C20	−94.8 (4)	C19—C4—C18—O2	108.2 (4)
C11—C9—C10—C1	−34.0 (5)	C5—C4—C18—O2	−130.6 (4)
C8—C9—C10—C1	145.8 (3)	C3—C4—C18—O3	176.3 (3)
C11—C9—C10—C5	−151.5 (4)	C19—C4—C18—O3	−66.9 (4)
C8—C9—C10—C5	28.3 (4)	C5—C4—C18—O3	54.3 (4)
C2—C1—C10—C9	−168.8 (3)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H1O3···O1i	0.82 (5)	1.83 (5)	2.637 (4)	169 (5)
O1—H1O1···O2	0.96 (7)	1.94 (6)	2.651 (4)	129 (5)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H1O3⋯O1i	0.82 (5)	1.83 (5)	2.637 (4)	169 (5)
O1—H1O1⋯O2	0.96 (7)	1.94 (6)	2.651 (4)	129 (5)

Symmetry code: (i) .