(4R,5R,6S,7R,8S,9R,10S,13S)-7,8β-Epoxy-momilactone-A.

The title compound, C(20)H(26)O(4), was extracted from Leucas Urticifolia, a wild Lamiaceae herb distributed in the Punjab, Baluchistan, Sindh and the Rajputana desert of Pakistan. The plant is utilized for various medicinal applications by the local community. The title compound is based on the pimarane-diterpene skeleton. The mol-ecule exhibits an ep-oxy ring fused to momilactone-A, leading to a penta-cyclic mol-ecular structure. The absolute configuration was assigned by comparison with the crystal structure of momilactone, but needs further verification. The crystal structure is governed by four inter-molecular hydrogen-bond inter-actions of the C-H⋯O type.

Related literature

For related literature, see: Bhattecharjee (2004 ▶); Germain & Deslongchamps (2002 ▶); Kato et al. (1973 ▶); Kiritikhar & Basu (2005 ▶); Misra et al. (1992 ▶, 1993 ▶, 1995 ▶).

Experimental

Crystal data

C20H26O4

M = 330.41

Orthorhombic,

a = 6.3996 (7) Å

b = 13.1759 (3) Å

c = 20.854 (1) Å

V = 1758.4 (2) Å3

Z = 4

Mo Kα radiation

μ = 0.09 mm−1

T = 296 (2) K

0.25 × 0.10 × 0.09 mm

Data collection

Bruker Kappa APEXII CCD diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T min = 0.980, T max = 0.990

19288 measured reflections

2635 independent reflections

1202 reflections with I > 2σ(I)

R int = 0.075

Refinement

R[F 2 > 2σ(F 2)] = 0.050

wR(F 2) = 0.117

S = 1.03

2635 reflections

223 parameters

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.14 e Å−3

Δρmin = −0.17 e Å−3

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: APEX2; data reduction: SAINT (Bruker, 2007 ▶); 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, 2003 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶) and PLATON.

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808010556/im2057sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808010556/im2057Isup2.hkl

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

C20H26O4	F000 = 712
Mr = 330.41	Dx = 1.248 Mg m−3
Orthorhombic, P212121	Mo Kα radiation λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 1295 reflections
a = 6.3996 (7) Å	θ = 1.6–28.6º
b = 13.1759 (3) Å	µ = 0.09 mm−1
c = 20.854 (1) Å	T = 296 (2) K
V = 1758.4 (2) Å3	Needle, colourless
Z = 4	0.25 × 0.10 × 0.09 mm

Bruker Kappa APEX2 CCD diffractometer	2635 independent reflections
Radiation source: fine-focus sealed tube	1202 reflections with I > 2σ(I)
Monochromator: graphite	Rint = 0.075
Detector resolution: 7.30 pixels mm-1	θmax = 28.9º
T = 296(2) K	θmin = 2.5º
ω scans	h = −8→8
Absorption correction: multi-scan(SADABS; Bruker, 2005)	k = −17→14
Tmin = 0.980, Tmax = 0.990	l = −28→28
19288 measured reflections

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)] = 0.050	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.117	w = 1/[σ2(Fo2) + (0.0443P)2 + 0.0772P] where P = (Fo2 + 2Fc2)/3
S = 1.03	(Δ/σ)max < 0.001
2635 reflections	Δρmax = 0.14 e Å−3
223 parameters	Δρmin = −0.17 e Å−3
Primary atom site location: structure-invariant direct methods	Extinction coefficient: ?

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. The low data parameter ratio is due to the small size of the crystal as well as to the absence of heavy atoms.

	x	y	z	Uiso*/Ueq
O1	0.2901 (4)	0.5384 (2)	0.77739 (11)	0.1276 (11)
O2	0.6901 (4)	0.54820 (17)	0.70678 (11)	0.0895 (7)
O3	0.6511 (3)	0.64702 (13)	0.62196 (9)	0.0641 (5)
O4	0.4101 (3)	0.82859 (12)	0.50957 (8)	0.0624 (5)
C1	0.0673 (4)	0.7697 (2)	0.70647 (13)	0.0687 (8)
H1A	−0.0511	0.7524	0.6796	0.082*
H1B	0.0347	0.8324	0.7288	0.082*
C2	0.1031 (5)	0.6849 (2)	0.75567 (14)	0.0848 (10)
H2A	0.1551	0.7159	0.7947	0.102*
H2B	−0.0316	0.6551	0.7657	0.102*
C3	0.2466 (5)	0.6019 (3)	0.73828 (15)	0.0739 (9)
C4	0.3374 (5)	0.5948 (2)	0.67075 (12)	0.0577 (7)
C5	0.2923 (4)	0.68587 (18)	0.62796 (11)	0.0499 (7)
H5	0.1673	0.6716	0.6024	0.060*
C6	0.4805 (4)	0.68849 (19)	0.58381 (11)	0.0553 (7)
H6	0.4545	0.6434	0.5473	0.066*
C7	0.5436 (4)	0.7907 (2)	0.55901 (11)	0.0535 (7)
H7	0.6937	0.8028	0.5537	0.064*
C8	0.4140 (4)	0.87944 (18)	0.57182 (11)	0.0462 (6)
C9	0.2192 (4)	0.86667 (18)	0.61280 (11)	0.0459 (6)
H9	0.1100	0.8397	0.5846	0.055*
C10	0.2590 (4)	0.78561 (18)	0.66466 (11)	0.0449 (6)
C11	0.1424 (5)	0.9704 (2)	0.63641 (13)	0.0654 (8)
H11A	0.0037	0.9639	0.6547	0.078*
H11B	0.2354	0.9960	0.6694	0.078*
C12	0.1373 (5)	1.0436 (2)	0.57995 (14)	0.0672 (8)
H12A	0.0686	1.1058	0.5932	0.081*
H12B	0.0551	1.0139	0.5457	0.081*
C13	0.3552 (5)	1.06931 (19)	0.55425 (14)	0.0631 (8)
C14	0.5096 (4)	0.98319 (19)	0.57133 (14)	0.0608 (8)
H14A	0.6235	0.9839	0.5406	0.073*
H14B	0.5684	0.9968	0.6133	0.073*
C15	0.3421 (6)	1.0775 (3)	0.48310 (17)	0.0956 (12)
H15	0.3070	1.0178	0.4619	0.115*
C16	0.3716 (10)	1.1536 (5)	0.4474 (3)	0.171 (3)
C17	0.4321 (6)	1.1672 (2)	0.5862 (2)	0.1304 (16)
H17A	0.4403	1.1573	0.6317	0.196*
H17B	0.3363	1.2213	0.5770	0.196*
H17C	0.5679	1.1843	0.5699	0.196*
C18	0.5739 (5)	0.5923 (2)	0.67153 (14)	0.0635 (8)
C19	0.2609 (7)	0.4944 (2)	0.64183 (16)	0.1028 (13)
H19A	0.1109	0.4939	0.6409	0.154*
H19B	0.3099	0.4389	0.6675	0.154*
H19C	0.3139	0.4876	0.5990	0.154*
C20	0.4458 (4)	0.81615 (19)	0.70649 (11)	0.0535 (7)
H20A	0.5665	0.8259	0.6799	0.080*
H20B	0.4735	0.7635	0.7372	0.080*
H20C	0.4143	0.8782	0.7286	0.080*
H16A	0.378 (5)	1.143 (2)	0.4045 (13)	0.080*
H16B	0.397 (5)	1.214 (2)	0.4727 (13)	0.080*

	U11	U22	U33	U12	U13	U23
O1	0.124 (2)	0.153 (2)	0.1054 (19)	0.0407 (19)	0.0296 (18)	0.0790 (18)
O2	0.0755 (17)	0.0982 (17)	0.0950 (15)	0.0171 (13)	−0.0114 (13)	0.0445 (13)
O3	0.0669 (13)	0.0666 (12)	0.0588 (11)	0.0172 (10)	0.0070 (11)	0.0134 (10)
O4	0.0828 (15)	0.0634 (12)	0.0409 (10)	0.0064 (10)	−0.0036 (9)	0.0013 (9)
C1	0.0527 (19)	0.082 (2)	0.0713 (19)	−0.0007 (16)	0.0122 (16)	0.0101 (18)
C2	0.072 (2)	0.105 (3)	0.078 (2)	−0.011 (2)	0.0138 (18)	0.028 (2)
C3	0.061 (2)	0.084 (2)	0.077 (2)	−0.0048 (19)	−0.0003 (18)	0.0255 (19)
C4	0.063 (2)	0.0541 (17)	0.0558 (18)	−0.0116 (16)	−0.0113 (16)	0.0105 (14)
C5	0.0542 (18)	0.0468 (16)	0.0487 (14)	−0.0096 (13)	−0.0153 (13)	0.0047 (13)
C6	0.074 (2)	0.0522 (18)	0.0399 (14)	0.0088 (15)	−0.0037 (15)	−0.0001 (13)
C7	0.0567 (18)	0.0583 (18)	0.0455 (15)	0.0058 (14)	0.0061 (14)	0.0049 (13)
C8	0.0454 (16)	0.0496 (16)	0.0435 (14)	0.0008 (13)	−0.0021 (13)	−0.0003 (12)
C9	0.0398 (16)	0.0517 (16)	0.0462 (14)	0.0009 (12)	−0.0024 (13)	0.0008 (13)
C10	0.0387 (15)	0.0545 (17)	0.0415 (13)	−0.0029 (12)	−0.0001 (13)	−0.0006 (13)
C11	0.064 (2)	0.0643 (18)	0.0679 (19)	0.0148 (17)	0.0105 (16)	−0.0003 (16)
C12	0.069 (2)	0.0561 (18)	0.076 (2)	0.0125 (16)	0.0017 (18)	0.0033 (15)
C13	0.059 (2)	0.0462 (18)	0.084 (2)	−0.0008 (15)	−0.0015 (17)	0.0065 (16)
C14	0.0503 (18)	0.0530 (18)	0.0792 (19)	−0.0029 (14)	−0.0015 (17)	0.0058 (15)
C15	0.098 (3)	0.087 (3)	0.102 (3)	0.030 (2)	0.018 (2)	0.046 (2)
C16	0.207 (6)	0.156 (5)	0.150 (5)	0.099 (5)	0.068 (5)	0.061 (4)
C17	0.125 (4)	0.053 (2)	0.213 (5)	−0.012 (2)	−0.034 (3)	−0.014 (3)
C18	0.075 (2)	0.0528 (18)	0.0624 (19)	0.0052 (17)	−0.0019 (19)	0.0097 (16)
C19	0.132 (3)	0.054 (2)	0.123 (3)	−0.0241 (19)	−0.047 (3)	0.0172 (19)
C20	0.0569 (18)	0.0573 (17)	0.0462 (14)	−0.0039 (14)	−0.0069 (13)	−0.0065 (13)

O1—C3	1.201 (3)	C9—C10	1.541 (3)
O2—C18	1.196 (3)	C9—H9	0.9800
O3—C18	1.354 (3)	C10—C20	1.534 (3)
O3—C6	1.457 (3)	C11—C12	1.523 (3)
O4—C7	1.429 (3)	C11—H11A	0.9700
O4—C8	1.461 (3)	C11—H11B	0.9700
C1—C10	1.519 (3)	C12—C13	1.532 (4)
C1—C2	1.534 (4)	C12—H12A	0.9700
C1—H1A	0.9700	C12—H12B	0.9700
C1—H1B	0.9700	C13—C15	1.490 (4)
C2—C3	1.474 (4)	C13—C17	1.533 (4)
C2—H2A	0.9700	C13—C14	1.546 (4)
C2—H2B	0.9700	C14—H14A	0.9700
C3—C4	1.526 (4)	C14—H14B	0.9700
C4—C18	1.514 (4)	C15—C16	1.263 (6)
C4—C5	1.523 (3)	C15—H15	0.9300
C4—C19	1.534 (4)	C16—H16A	0.91 (2)
C5—C6	1.516 (4)	C16—H16B	0.97 (2)
C5—C10	1.536 (3)	C17—H17A	0.9600
C5—H5	0.9800	C17—H17B	0.9600
C6—C7	1.499 (3)	C17—H17C	0.9600
C6—H6	0.9800	C19—H19A	0.9600
C7—C8	1.458 (3)	C19—H19B	0.9600
C7—H7	0.9800	C19—H19C	0.9600
C8—C14	1.498 (3)	C20—H20A	0.9600
C8—C9	1.521 (3)	C20—H20B	0.9600
C9—C11	1.533 (3)	C20—H20C	0.9600
C18—O3—C6	110.1 (2)	C20—C10—C5	113.6 (2)
C7—O4—C8	60.57 (15)	C1—C10—C9	111.4 (2)
C10—C1—C2	111.3 (2)	C20—C10—C9	110.3 (2)
C10—C1—H1A	109.4	C5—C10—C9	105.44 (18)
C2—C1—H1A	109.4	C12—C11—C9	108.9 (2)
C10—C1—H1B	109.4	C12—C11—H11A	109.9
C2—C1—H1B	109.4	C9—C11—H11A	109.9
H1A—C1—H1B	108.0	C12—C11—H11B	109.9
C3—C2—C1	118.0 (3)	C9—C11—H11B	109.9
C3—C2—H2A	107.8	H11A—C11—H11B	108.3
C1—C2—H2A	107.8	C11—C12—C13	113.0 (2)
C3—C2—H2B	107.8	C11—C12—H12A	109.0
C1—C2—H2B	107.8	C13—C12—H12A	109.0
H2A—C2—H2B	107.1	C11—C12—H12B	109.0
O1—C3—C2	119.6 (3)	C13—C12—H12B	109.0
O1—C3—C4	119.7 (3)	H12A—C12—H12B	107.8
C2—C3—C4	120.6 (3)	C15—C13—C12	108.3 (3)
C18—C4—C5	102.3 (2)	C15—C13—C17	112.9 (3)
C18—C4—C3	111.8 (2)	C12—C13—C17	109.0 (3)
C5—C4—C3	114.9 (2)	C15—C13—C14	108.6 (2)
C18—C4—C19	107.7 (3)	C12—C13—C14	109.8 (2)
C5—C4—C19	112.9 (2)	C17—C13—C14	108.2 (3)
C3—C4—C19	107.1 (3)	C8—C14—C13	114.2 (2)
C6—C5—C4	102.9 (2)	C8—C14—H14A	108.7
C6—C5—C10	113.2 (2)	C13—C14—H14A	108.7
C4—C5—C10	114.10 (19)	C8—C14—H14B	108.7
C6—C5—H5	108.8	C13—C14—H14B	108.7
C4—C5—H5	108.8	H14A—C14—H14B	107.6
C10—C5—H5	108.8	C16—C15—C13	129.5 (5)
O3—C6—C7	108.9 (2)	C16—C15—H15	115.2
O3—C6—C5	104.77 (18)	C13—C15—H15	115.2
C7—C6—C5	116.4 (2)	C15—C16—H16A	118 (2)
O3—C6—H6	108.9	C15—C16—H16B	111 (2)
C7—C6—H6	108.9	H16A—C16—H16B	131 (3)
C5—C6—H6	108.9	C13—C17—H17A	109.5
O4—C7—C8	60.81 (15)	C13—C17—H17B	109.5
O4—C7—C6	113.7 (2)	H17A—C17—H17B	109.5
C8—C7—C6	120.3 (2)	C13—C17—H17C	109.5
O4—C7—H7	116.7	H17A—C17—H17C	109.5
C8—C7—H7	116.7	H17B—C17—H17C	109.5
C6—C7—H7	116.7	O2—C18—O3	120.1 (3)
C7—C8—O4	58.63 (14)	O2—C18—C4	129.7 (3)
C7—C8—C14	119.9 (2)	O3—C18—C4	110.2 (3)
O4—C8—C14	114.8 (2)	C4—C19—H19A	109.5
C7—C8—C9	118.7 (2)	C4—C19—H19B	109.5
O4—C8—C9	115.74 (19)	H19A—C19—H19B	109.5
C14—C8—C9	116.1 (2)	C4—C19—H19C	109.5
C8—C9—C11	110.2 (2)	H19A—C19—H19C	109.5
C8—C9—C10	109.59 (19)	H19B—C19—H19C	109.5
C11—C9—C10	116.4 (2)	C10—C20—H20A	109.5
C8—C9—H9	106.7	C10—C20—H20B	109.5
C11—C9—H9	106.7	H20A—C20—H20B	109.5
C10—C9—H9	106.7	C10—C20—H20C	109.5
C1—C10—C20	109.82 (19)	H20A—C20—H20C	109.5
C1—C10—C5	106.3 (2)	H20B—C20—H20C	109.5
C10—C1—C2—C3	−30.0 (4)	C2—C1—C10—C20	−60.7 (3)
C1—C2—C3—O1	174.5 (3)	C2—C1—C10—C5	62.5 (3)
C1—C2—C3—C4	−6.6 (4)	C2—C1—C10—C9	176.9 (2)
O1—C3—C4—C18	−57.0 (4)	C6—C5—C10—C1	−179.6 (2)
C2—C3—C4—C18	124.1 (3)	C4—C5—C10—C1	−62.4 (3)
O1—C3—C4—C5	−173.1 (3)	C6—C5—C10—C20	−58.8 (3)
C2—C3—C4—C5	8.0 (4)	C4—C5—C10—C20	58.5 (3)
O1—C3—C4—C19	60.7 (4)	C6—C5—C10—C9	62.1 (3)
C2—C3—C4—C19	−118.2 (3)	C4—C5—C10—C9	179.3 (2)
C18—C4—C5—C6	28.8 (2)	C8—C9—C10—C1	−179.5 (2)
C3—C4—C5—C6	150.2 (2)	C11—C9—C10—C1	54.6 (3)
C19—C4—C5—C6	−86.7 (3)	C8—C9—C10—C20	58.3 (2)
C18—C4—C5—C10	−94.2 (3)	C11—C9—C10—C20	−67.5 (3)
C3—C4—C5—C10	27.2 (3)	C8—C9—C10—C5	−64.7 (2)
C19—C4—C5—C10	150.3 (3)	C11—C9—C10—C5	169.5 (2)
C18—O3—C6—C7	145.2 (2)	C8—C9—C11—C12	47.6 (3)
C18—O3—C6—C5	20.1 (3)	C10—C9—C11—C12	173.2 (2)
C4—C5—C6—O3	−30.2 (2)	C9—C11—C12—C13	−67.5 (3)
C10—C5—C6—O3	93.4 (2)	C11—C12—C13—C15	142.6 (3)
C4—C5—C6—C7	−150.5 (2)	C11—C12—C13—C17	−94.1 (3)
C10—C5—C6—C7	−26.9 (3)	C11—C12—C13—C14	24.2 (3)
C8—O4—C7—C6	112.7 (2)	C7—C8—C14—C13	153.1 (2)
O3—C6—C7—O4	166.57 (18)	O4—C8—C14—C13	86.4 (3)
C5—C6—C7—O4	−75.4 (3)	C9—C8—C14—C13	−52.9 (3)
O3—C6—C7—C8	−124.6 (2)	C15—C13—C14—C8	−84.6 (3)
C5—C6—C7—C8	−6.5 (3)	C12—C13—C14—C8	33.6 (3)
C6—C7—C8—O4	−101.9 (3)	C17—C13—C14—C8	152.5 (3)
O4—C7—C8—C14	−102.5 (3)	C12—C13—C15—C16	115.8 (5)
C6—C7—C8—C14	155.6 (2)	C17—C13—C15—C16	−5.0 (6)
O4—C7—C8—C9	104.2 (2)	C14—C13—C15—C16	−125.0 (5)
C6—C7—C8—C9	2.3 (3)	C6—O3—C18—O2	176.6 (3)
C7—O4—C8—C14	111.2 (2)	C6—O3—C18—C4	−1.0 (3)
C7—O4—C8—C9	−109.3 (2)	C5—C4—C18—O2	164.5 (3)
C7—C8—C9—C11	163.7 (2)	C3—C4—C18—O2	41.0 (4)
O4—C8—C9—C11	−129.6 (2)	C19—C4—C18—O2	−76.3 (4)
C14—C8—C9—C11	9.4 (3)	C5—C4—C18—O3	−18.1 (3)
C7—C8—C9—C10	34.3 (3)	C3—C4—C18—O3	−141.6 (2)
O4—C8—C9—C10	101.1 (2)	C19—C4—C18—O3	101.0 (3)
C14—C8—C9—C10	−119.9 (2)

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2B···O2i	0.97	2.58	3.356 (5)	137
C7—H7···O4ii	0.98	2.58	3.164 (4)	118
C11—H11A···O1iii	0.97	2.55	3.420 (5)	149
C14—H14B···O1iv	0.97	2.52	3.486 (5)	178

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C2—H2B⋯O2i	0.97	2.58	3.356 (5)	137
C7—H7⋯O4ii	0.98	2.58	3.164 (4)	118
C11—H11A⋯O1iii	0.97	2.55	3.420 (5)	149
C14—H14B⋯O1iv	0.97	2.52	3.486 (5)	178

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) .