1-(4a,8-Dimethyl-1,2,3,4,4a,5,6,8a-octa-hydro-naphthalen-2-yl)-3-phenyl-prop-2-en-1-one.

The title compound, C(21)H(26)O, was semisynthesized from isocostic acid, isolated from the aerial part of Inula Viscosa- (L) Aiton [or Dittrichia Viscosa- (L) Greuter]. The cyclo-hexene ring has a half-chair conformation, whereas the cyclo-hexane ring displays a chair conformation.

Related literature

For background to the medicinal inter­est in Inula Viscosa­ (L) Aiton [or Dittrichia Viscosa­ (L) Greuter], see: Shtacher & Kasshman (1970 ▶); Bohlman & Gupta (1982 ▶); Azoulay et al. (1986 ▶); Bohlmann et al. (1977 ▶); Ceccherelli et al. (1988 ▶). For the synthesis, see: Kutney & Singh (1984 ▶). For conformational analysis, see: Cremer & Pople (1975 ▶).

Experimental

Crystal data

C21H26O

M = 294.42

Orthorhombic,

a = 9.5760 (8) Å

b = 11.3542 (11) Å

c = 15.7852 (13) Å

V = 1716.3 (3) Å3

Z = 4

Mo Kα radiation

μ = 0.07 mm−1

T = 180 K

0.37 × 0.16 × 0.16 mm

Data collection

Agilent Xcalibur Eos Gemini ultra diffractometer

Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2010 ▶) T min = 0.817, T max = 1.000

10251 measured reflections

3436 independent reflections

3180 reflections with I > 2σ(I)

R int = 0.022

Refinement

R[F 2 > 2σ(F 2)] = 0.037

wR(F 2) = 0.089

S = 1.05

3436 reflections

201 parameters

H-atom parameters constrained

Δρmax = 0.15 e Å−3

Δρmin = −0.15 e Å−3

Data collection: CrysAlis PRO (Agilent, 2010 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; 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 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811010452/fj2408sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811010452/fj2408Isup2.hkl

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

C21H26O	F(000) = 640
Mr = 294.42	Dx = 1.139 Mg m−3
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 6842 reflections
a = 9.5760 (8) Å	θ = 3.3–27.2°
b = 11.3542 (11) Å	µ = 0.07 mm−1
c = 15.7852 (13) Å	T = 180 K
V = 1716.3 (3) Å3	Box, colorless
Z = 4	0.37 × 0.16 × 0.16 mm

Agilent Xcalibur Eos Gemini ultra diffractometer	3436 independent reflections
Radiation source: Enhance (Mo) X-ray Source	3180 reflections with I > 2σ(I)
graphite	Rint = 0.022
Detector resolution: 16.1978 pixels mm-1	θmax = 26.4°, θmin = 3.3°
ω scans	h = −11→11
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2010)	k = −14→14
Tmin = 0.817, Tmax = 1.000	l = −19→19
10251 measured reflections

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) = 0.089	H-atom parameters constrained
S = 1.05	w = 1/[σ2(Fo2) + (0.0379P)2 + 0.290P] where P = (Fo2 + 2Fc2)/3
3436 reflections	(Δ/σ)max < 0.001
201 parameters	Δρmax = 0.15 e Å−3
0 restraints	Δρmin = −0.15 e Å−3

Experimental. Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm. CrysAlisPro (Agilent Technologies, 2010)

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 > 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
C8A	0.19916 (15)	0.40195 (13)	0.37785 (8)	0.0301 (3)
H1	0.2470	0.4777	0.3713	0.036*
C8	0.13546 (16)	0.40428 (13)	0.46570 (9)	0.0336 (3)
C7	0.00699 (18)	0.44778 (15)	0.47799 (10)	0.0451 (4)
H7	−0.0253	0.4519	0.5335	0.054*
C6	−0.08850 (18)	0.49016 (17)	0.40973 (10)	0.0472 (4)
H6A	−0.1260	0.5664	0.4256	0.057*
H6B	−0.1661	0.4358	0.4043	0.057*
C5	−0.01461 (17)	0.50089 (15)	0.32443 (9)	0.0401 (4)
H5A	0.0366	0.5746	0.3228	0.048*
H5B	−0.0840	0.5029	0.2797	0.048*
C4A	0.08624 (15)	0.39923 (13)	0.30807 (9)	0.0304 (3)
C4	0.15939 (18)	0.41743 (16)	0.22242 (9)	0.0426 (4)
H4B	0.0903	0.4132	0.1776	0.051*
H4A	0.2002	0.4956	0.2212	0.051*
C3	0.27356 (17)	0.32686 (17)	0.20516 (9)	0.0437 (4)
H3A	0.3206	0.3466	0.1526	0.052*
H3B	0.2314	0.2498	0.1983	0.052*
C2	0.38162 (15)	0.32205 (13)	0.27753 (9)	0.0314 (3)
H2	0.4344	0.3960	0.2776	0.038*
C1	0.31110 (15)	0.30807 (13)	0.36395 (8)	0.0313 (3)
H1B	0.2688	0.2306	0.3676	0.038*
H1A	0.3809	0.3141	0.4083	0.038*
C9	0.48216 (15)	0.22168 (13)	0.25939 (9)	0.0332 (3)
C10	0.60358 (16)	0.24005 (13)	0.20307 (9)	0.0348 (3)
H10	0.6567	0.1742	0.1894	0.042*
C11	0.64329 (14)	0.34209 (13)	0.17044 (9)	0.0321 (3)
H11	0.5932	0.4083	0.1871	0.039*
C12	0.75915 (15)	0.36131 (13)	0.11029 (8)	0.0309 (3)
C13	0.82643 (17)	0.27048 (15)	0.06720 (10)	0.0391 (4)
H13	0.8003	0.1928	0.0769	0.047*
C14	0.93184 (17)	0.29534 (16)	0.01017 (11)	0.0463 (4)
H14	0.9767	0.2342	−0.0180	0.056*
C15	0.97102 (17)	0.41042 (17)	−0.00528 (11)	0.0471 (4)
H15	1.0415	0.4268	−0.0440	0.056*
C16	0.90527 (16)	0.50077 (16)	0.03690 (10)	0.0422 (4)
H16	0.9315	0.5784	0.0268	0.051*
C17	0.80018 (15)	0.47621 (14)	0.09437 (9)	0.0343 (3)
H17	0.7564	0.5378	0.1227	0.041*
C20	0.00546 (18)	0.28311 (15)	0.30817 (11)	0.0445 (4)
H20A	−0.0312	0.2687	0.3638	0.067*
H20B	0.0669	0.2200	0.2925	0.067*
H20C	−0.0701	0.2877	0.2683	0.067*
C18	0.22086 (18)	0.36189 (18)	0.53939 (9)	0.0472 (4)
H18C	0.1687	0.3720	0.5908	0.071*
H18A	0.3058	0.4065	0.5426	0.071*
H18B	0.2427	0.2800	0.5319	0.071*
O1	0.46109 (12)	0.12334 (9)	0.28773 (7)	0.0471 (3)

	U11	U22	U33	U12	U13	U23
C8A	0.0304 (7)	0.0322 (7)	0.0277 (7)	−0.0013 (6)	0.0012 (6)	−0.0015 (6)
C8	0.0352 (8)	0.0357 (8)	0.0298 (7)	−0.0045 (7)	0.0025 (6)	−0.0017 (6)
C7	0.0428 (9)	0.0567 (10)	0.0358 (8)	0.0089 (8)	0.0101 (7)	0.0016 (7)
C6	0.0403 (9)	0.0534 (10)	0.0480 (9)	0.0150 (8)	0.0076 (7)	0.0009 (8)
C5	0.0392 (8)	0.0421 (8)	0.0389 (8)	0.0102 (8)	−0.0017 (7)	0.0046 (7)
C4A	0.0282 (7)	0.0349 (8)	0.0280 (7)	0.0027 (6)	−0.0013 (6)	0.0010 (6)
C4	0.0414 (9)	0.0582 (10)	0.0283 (7)	0.0103 (8)	−0.0008 (6)	0.0086 (7)
C3	0.0424 (9)	0.0620 (11)	0.0266 (7)	0.0095 (8)	0.0022 (7)	0.0010 (7)
C2	0.0293 (7)	0.0345 (8)	0.0305 (7)	−0.0002 (6)	0.0044 (6)	0.0019 (6)
C1	0.0300 (7)	0.0363 (8)	0.0275 (7)	0.0027 (7)	0.0001 (6)	0.0024 (6)
C9	0.0319 (7)	0.0373 (8)	0.0305 (7)	−0.0004 (7)	0.0008 (6)	−0.0010 (7)
C10	0.0328 (8)	0.0348 (8)	0.0367 (8)	0.0064 (6)	0.0035 (6)	−0.0037 (7)
C11	0.0289 (7)	0.0380 (8)	0.0294 (7)	0.0036 (7)	0.0000 (6)	−0.0026 (6)
C12	0.0258 (7)	0.0393 (8)	0.0277 (7)	0.0007 (6)	−0.0042 (6)	−0.0005 (6)
C13	0.0385 (8)	0.0403 (9)	0.0384 (8)	0.0007 (7)	0.0038 (7)	−0.0042 (7)
C14	0.0401 (9)	0.0569 (11)	0.0420 (9)	0.0041 (8)	0.0081 (7)	−0.0113 (8)
C15	0.0338 (8)	0.0683 (11)	0.0392 (9)	−0.0040 (9)	0.0088 (7)	0.0015 (8)
C16	0.0334 (8)	0.0469 (9)	0.0463 (9)	−0.0051 (8)	−0.0005 (7)	0.0083 (8)
C17	0.0273 (7)	0.0386 (8)	0.0368 (8)	0.0036 (7)	−0.0016 (6)	0.0006 (7)
C20	0.0351 (8)	0.0450 (9)	0.0535 (10)	−0.0043 (7)	−0.0060 (8)	−0.0080 (8)
C18	0.0429 (9)	0.0710 (12)	0.0278 (7)	0.0021 (9)	0.0022 (7)	0.0029 (8)
O1	0.0494 (7)	0.0350 (6)	0.0568 (7)	0.0033 (5)	0.0149 (6)	0.0062 (5)

C8A—C8	1.5153 (19)	C1—H1B	0.9700
C8A—C1	1.528 (2)	C1—H1A	0.9700
C8A—C4A	1.5439 (19)	C9—O1	1.2197 (17)
C8A—H1	0.9800	C9—C10	1.478 (2)
C8—C7	1.340 (2)	C10—C11	1.324 (2)
C8—C18	1.501 (2)	C10—H10	0.9300
C7—C6	1.493 (2)	C11—C12	1.4765 (19)
C7—H7	0.9300	C11—H11	0.9300
C6—C5	1.526 (2)	C12—C17	1.385 (2)
C6—H6A	0.9700	C12—C13	1.393 (2)
C6—H6B	0.9700	C13—C14	1.382 (2)
C5—C4A	1.527 (2)	C13—H13	0.9300
C5—H5A	0.9700	C14—C15	1.381 (3)
C5—H5B	0.9700	C14—H14	0.9300
C4A—C20	1.529 (2)	C15—C16	1.376 (2)
C4A—C4	1.537 (2)	C15—H15	0.9300
C4—C3	1.525 (2)	C16—C17	1.383 (2)
C4—H4B	0.9700	C16—H16	0.9300
C4—H4A	0.9700	C17—H17	0.9300
C3—C2	1.542 (2)	C20—H20A	0.9600
C3—H3A	0.9700	C20—H20B	0.9600
C3—H3B	0.9700	C20—H20C	0.9600
C2—C9	1.519 (2)	C18—H18C	0.9600
C2—C1	1.5304 (18)	C18—H18A	0.9600
C2—H2	0.9800	C18—H18B	0.9600
C8—C8A—C1	115.22 (12)	C3—C2—H2	108.4
C8—C8A—C4A	111.80 (11)	C8A—C1—C2	111.42 (11)
C1—C8A—C4A	112.03 (11)	C8A—C1—H1B	109.3
C8—C8A—H1	105.6	C2—C1—H1B	109.3
C1—C8A—H1	105.6	C8A—C1—H1A	109.3
C4A—C8A—H1	105.6	C2—C1—H1A	109.3
C7—C8—C18	120.41 (14)	H1B—C1—H1A	108.0
C7—C8—C8A	120.57 (14)	O1—C9—C10	118.67 (13)
C18—C8—C8A	118.96 (13)	O1—C9—C2	120.85 (13)
C8—C7—C6	125.23 (14)	C10—C9—C2	120.39 (12)
C8—C7—H7	117.4	C11—C10—C9	125.69 (13)
C6—C7—H7	117.4	C11—C10—H10	117.2
C7—C6—C5	112.24 (13)	C9—C10—H10	117.2
C7—C6—H6A	109.2	C10—C11—C12	126.55 (13)
C5—C6—H6A	109.2	C10—C11—H11	116.7
C7—C6—H6B	109.2	C12—C11—H11	116.7
C5—C6—H6B	109.2	C17—C12—C13	118.51 (14)
H6A—C6—H6B	107.9	C17—C12—C11	117.97 (13)
C6—C5—C4A	112.47 (13)	C13—C12—C11	123.50 (14)
C6—C5—H5A	109.1	C14—C13—C12	120.31 (16)
C4A—C5—H5A	109.1	C14—C13—H13	119.8
C6—C5—H5B	109.1	C12—C13—H13	119.8
C4A—C5—H5B	109.1	C15—C14—C13	120.45 (16)
H5A—C5—H5B	107.8	C15—C14—H14	119.8
C5—C4A—C20	109.37 (12)	C13—C14—H14	119.8
C5—C4A—C4	109.61 (12)	C16—C15—C14	119.72 (15)
C20—C4A—C4	110.34 (13)	C16—C15—H15	120.1
C5—C4A—C8A	107.89 (12)	C14—C15—H15	120.1
C20—C4A—C8A	111.77 (12)	C15—C16—C17	120.01 (16)
C4—C4A—C8A	107.80 (11)	C15—C16—H16	120.0
C3—C4—C4A	113.16 (13)	C17—C16—H16	120.0
C3—C4—H4B	108.9	C16—C17—C12	121.01 (15)
C4A—C4—H4B	108.9	C16—C17—H17	119.5
C3—C4—H4A	108.9	C12—C17—H17	119.5
C4A—C4—H4A	108.9	C4A—C20—H20A	109.5
H4B—C4—H4A	107.8	C4A—C20—H20B	109.5
C4—C3—C2	111.86 (13)	H20A—C20—H20B	109.5
C4—C3—H3A	109.2	C4A—C20—H20C	109.5
C2—C3—H3A	109.2	H20A—C20—H20C	109.5
C4—C3—H3B	109.2	H20B—C20—H20C	109.5
C2—C3—H3B	109.2	C8—C18—H18C	109.5
H3A—C3—H3B	107.9	C8—C18—H18A	109.5
C9—C2—C1	111.70 (12)	H18C—C18—H18A	109.5
C9—C2—C3	108.19 (12)	C8—C18—H18B	109.5
C1—C2—C3	111.58 (12)	H18C—C18—H18B	109.5
C9—C2—H2	108.4	H18A—C18—H18B	109.5
C1—C2—H2	108.4