(4aS*,10aR*)-7-Hydr­oxy-8-isopropyl-1,1,4a-trimethyl-1,2,3,4,4a,9,10,10a-octa­hydro­phenanthren-2-one

The title compound, C₂₀H₂₈O₂, is a new totarolone which was isolated from Tetra­clinis articulata wood. The mol­ecule forms an extended sheet of three fused rings which exhibit different conformations. The non-aromatic oxo-substituted ring has a screw boat conformation, while the central ring has a half-chair conformation. Mol­ecules are linked to each other by inter­molecular O—H...O hydrogen bonds involving carbonyl and hydroxyl groups.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.045
• wR factor = 0.125
• Data-to-parameter ratio = 12.3

checkCIF/PLATON results

No syntax errors found



Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           29.99
           From the CIF: _reflns_number_total               2537
           Count of symmetry unique reflns         2581
           Completeness (_total/calc)             98.30%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured         0
           Fraction of Friedel pairs measured     0.000
           Are heavy atom types Z>Si present         no
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C4A    = .          S
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C10A   = .          R
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          1

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   0 ALERT level C = Check and explain
   4 ALERT level G = General alerts; check

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

Natural products, through evolution of producing organisms have many biological activities that are manifested through an array of different molecular target sites. Thus, diterpenoids isolated from plants have good pharmacological activities (Atta-Ur-Rahman & Choudary, 1999, Panter et al., 2002). The duvatriene-diols from tobacco leaf surfaces are phytotoxics to serious weed Echinocloa crus-galli (Lawsen et al., 1988). Some of them have been suggested as herbicides (Macias et al., 2000). In our study, we are interested to the aromatic and medicinal plant: Tetraclinis articulata which was subsequently used in traditional medicine (Bellakhdar, 1997). Some of its oxygenated compounds are effective as an antibiotic (Vlietinck, 1987), antifongic (Evidente et al., 1997), cytotoxic (Comte et al., 1995) and inhibit various human leukocyte functions (Barrero et al., 2003). In order to isolate similar compounds, we have studied the hexanic extract of Tetraclinis articulata wood. Thus, extraction with hexane using a soxhlet apparatus allow us to isolate compound (I), new diterpenic isomer of (4aS,6cS)-8-Hydroxy-9-isopropyl-4,4,6c-trimethyl-1,2,3,4,4a,5,6, 6c-octahydrophenanthren-3-one (Zeroual et al., 2007). The structure of (I) was established by ¹H and ¹³C NMR and confirmed by its single-crystal X-ray structure.

The molecule (I) is built up from three fused six-membered rings. The non aromatic oxo-substituted ring has a screw boat conformation, as indicated by the total puckering amplitude QT = 0.63 (2)Å and spherical polar angle θ =-82.16 (2)° with φ = 76.89 (2)°. While the central ring has a half chair conformation with QT = 0.53 (2) Å, θ =127.66 (2)°, φ = 151.53 (2)° (Cremer & Pople, 1975). Molecules are linked by intermolecular O—H···O hydrogen bonds (Table 1, Figure 2) involving the carbonyl and the hydroxyl groups and propagate in chain parallel to the (101) plane.

Related literature

For related literature, see: Atta-Ur-Rahman & Choudary (1999); Barrero et al. (2003); Bellakhdar (1997); Comte et al. (1995); Cremer & Pople (1975); Evidente et al. (1997); Lawsen et al. (1988); Macias et al. (2000); Panter et al. (2002); Vlietinck (1987); Zeroual et al. (2007).

S2. Experimental

Continuous extraction with hexane employing a soxhlet apparatus during 48 h of Tetraclinis articulata wood let us, after evaporation of hexane and chromatography using silica gel column with hexane/ethyl acetate (97/3) as an eluent, to isolate compound (I) in 75% yield. Suitable crystals of (I) were obtained by evaporation of a dichloromethane solution at 277 K. m.p. = 444–445 K (dichloromethane); Spectroscopic analysis: ¹H NMR (300 MHz, CDCl₃, δ, p.p.m.): 2.21 (2H, H3, m), 2.04 (2H, H4, m), 6.90 (1H, H5, d, J = 8.4 Hz), 6.50 (1H, H6, d, J = 8.4 Hz), 4.85 (OH, s), 2.85 (2H, H9, m), 1.56 (2H, H10, m), 1.78 (1H, H10a, dd, J1 = 10.7 Hz, J2 = 1.9 Hz), 3.10 (1H, H11, m), 1.28 (3H, H12, d, J = 10 Hz), 1.30 (3H, H13, d, J = 10 Hz), 1.42 (3H, H14, s), 1.11 (3H, H15, s), 1.08 (3H, H16, s); ¹³C NMR (75 MHz, CDCl₃, δ, p.p.m.): 47.5 (C1), 218.5 (C2), 38.3 (C3), 34.8 (C4), 37.5 (C4a), 131.3 (C4b), 124.0 (C5), 115.0 (C6), 152.9 (C7), 159.6 (C8), 140.1 (C8a), 28.9 (C9), 21.0 (C10), 49.8 (C10a), 26.8 (C11), 20.1 (C12), 20.2 (C13), 22.4 (C14), 24.8 (C15), 21.2 (C16).

S3. Refinement

Except H11 and O—H hydrogen atom, which were placed by Fourier synthesis C11—H11=0.99 (4) Å; O—H = 0.81 (4) Å), all H atoms attached to carbon atoms were fixed geometrically and treated as riding with C—H = 0.93 Å (aromatic), 0.96Å (methyl), 0.97 Å (methylene), and 0.98Å (methine) with U_iso(H) =1.2U_eq(aromatic, methylene, methine and OH) or U_iso(H) = 1.5U_eq(methyl).

In the absence of significant anomalous scattering, the absolute configuration could not be reliably determined and thus the Friedel pairs were merged and any references to the Flack parameter were removed.

Computing details

Data collection: COLLECT (Bruker–Nonius, 2006); cell refinement: DENZO AND SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO AND SCALEPACK; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

	Fig. 1. : Molecular structure of compound (I) with the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are represented as small spheres of arbitrary radii.
	Fig. 2. : Partial packing view showing the O—H···O interactions (dashed lines) and the formation of a chain parallel to the (101) plane. H atoms not involved in hydrogen bonding have been omitted for clarity. [Symmetry code: (i) -1 + x, y, 1 + z]

(4aS*,10aR*)-7-Hydroxy-8-isopropyl-1,1,4a-trimethyl-1,2,3,4,4a,9,10,10a- octahydrophenanthren-2-one

Crystal data

C20H28O2	F(000) = 328
Mr = 300.42	Dx = 1.172 Mg m^−3
Monoclinic, P21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2yb	Cell parameters from 2550 reflections
a = 7.1873 (4) Å	θ = 3.5–30.0°
b = 14.2273 (9) Å	µ = 0.07 mm^−1
c = 8.3860 (4) Å	T = 298 K
β = 96.952 (4)°	Prism, colourless
V = 851.21 (8) Å^3	0.30 × 0.25 × 0.20 mm
Z = 2

Data collection

Bruker–Nonius KappaCCD area-detector diffractometer	2329 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.034
Graphite monochromator	θmax = 30.0°, θmin = 2.9°
φ and ω scans	h = 0→10
10680 measured reflections	k = 0→20
2537 independent reflections	l = −11→11

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.045	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.126	w = 1/[σ^2(Fo^2) + (0.0779P)^2 + 0.0844P] where P = (Fo^2 + 2Fc^2)/3
S = 1.09	(Δ/σ)max < 0.001
2537 reflections	Δρmax = 0.19 e Å^−3
207 parameters	Δρmin = −0.19 e Å^−3
1 restraint	Absolute structure: unknown - see Supplementary Materials - Refinement section
Primary atom site location: structure-invariant direct methods

Special details

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
H	0.542 (5)	0.581 (3)	0.585 (4)	0.069 (10)*
H11	0.665 (4)	0.334 (3)	0.265 (4)	0.068 (9)*
C1	1.2274 (3)	0.52902 (14)	−0.1588 (2)	0.0380 (4)
C2	1.3486 (3)	0.61648 (15)	−0.1271 (2)	0.0398 (4)
C3	1.3735 (3)	0.6564 (2)	0.0381 (3)	0.0542 (6)
H3A	1.4179	0.7205	0.0311	0.065*
H3B	1.4722	0.6212	0.1009	0.065*
C4	1.2054 (3)	0.65802 (17)	0.1310 (3)	0.0471 (5)
H4A	1.1733	0.7230	0.1499	0.057*
H4B	1.2404	0.6289	0.2349	0.057*
C4A	1.0296 (2)	0.60751 (12)	0.0471 (2)	0.0330 (3)
C4B	0.8971 (2)	0.58501 (12)	0.1734 (2)	0.0332 (3)
C5	0.8517 (3)	0.65705 (14)	0.2743 (2)	0.0411 (4)
H5	0.8987	0.7170	0.2608	0.049*
C6	0.7385 (3)	0.64173 (15)	0.3939 (2)	0.0448 (4)
H6	0.7078	0.6913	0.4582	0.054*
C7	0.6712 (3)	0.55241 (15)	0.4172 (2)	0.0428 (4)
C8	0.7087 (3)	0.47748 (13)	0.3179 (2)	0.0371 (4)
C8A	0.8209 (2)	0.49546 (13)	0.1932 (2)	0.0330 (3)
C9	0.8596 (3)	0.41598 (13)	0.0819 (2)	0.0394 (4)
H9A	0.9486	0.3730	0.1394	0.047*
H9B	0.7442	0.3816	0.0514	0.047*
C10	0.9367 (3)	0.44883 (15)	−0.0687 (2)	0.0412 (4)
H10A	0.8390	0.4804	−0.1389	0.049*
H10B	0.9793	0.3952	−0.1258	0.049*
C10A	1.0988 (2)	0.51580 (12)	−0.02329 (19)	0.0333 (3)
H10	1.1775	0.4853	0.0654	0.040*
C11	0.6362 (3)	0.37951 (16)	0.3478 (3)	0.0441 (4)
C12	0.4239 (4)	0.3730 (2)	0.3432 (4)	0.0662 (7)
H12A	0.3892	0.3092	0.3627	0.099*
H12B	0.3653	0.3926	0.2396	0.099*
H12C	0.3836	0.4131	0.4245	0.099*
C13	0.7334 (5)	0.3358 (2)	0.5020 (4)	0.0752 (9)
H13A	0.6838	0.2741	0.5154	0.113*
H13B	0.7120	0.3744	0.5920	0.113*
H13C	0.8656	0.3316	0.4956	0.113*
C14	0.9273 (3)	0.67265 (15)	−0.0801 (3)	0.0469 (5)
H14A	0.8182	0.6413	−0.1323	0.070*
H14B	1.0095	0.6884	−0.1582	0.070*
H14C	0.8902	0.7290	−0.0296	0.070*
C15	1.3668 (3)	0.44607 (19)	−0.1482 (3)	0.0574 (6)
H15A	1.2991	0.3882	−0.1670	0.086*
H15B	1.4370	0.4447	−0.0433	0.086*
H15C	1.4511	0.4537	−0.2277	0.086*
C16	1.1232 (3)	0.5328 (2)	−0.3292 (2)	0.0567 (6)
H16A	1.0469	0.4776	−0.3484	0.085*
H16B	1.2124	0.5354	−0.4055	0.085*
H16C	1.0450	0.5877	−0.3403	0.085*
O1	0.5674 (3)	0.53377 (15)	0.5392 (2)	0.0646 (5)
O2	1.4340 (3)	0.65004 (15)	−0.2306 (2)	0.0618 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0377 (8)	0.0433 (9)	0.0349 (7)	−0.0009 (7)	0.0115 (6)	−0.0001 (7)
C2	0.0321 (8)	0.0469 (10)	0.0419 (9)	−0.0007 (7)	0.0105 (7)	0.0037 (8)
C3	0.0420 (10)	0.0700 (15)	0.0520 (11)	−0.0190 (11)	0.0122 (8)	−0.0117 (11)
C4	0.0409 (9)	0.0522 (11)	0.0501 (10)	−0.0126 (9)	0.0134 (8)	−0.0140 (9)
C4A	0.0323 (7)	0.0311 (8)	0.0374 (8)	−0.0010 (6)	0.0109 (6)	−0.0013 (6)
C4B	0.0318 (7)	0.0329 (8)	0.0364 (8)	0.0007 (6)	0.0096 (6)	−0.0019 (6)
C5	0.0442 (9)	0.0332 (8)	0.0485 (10)	−0.0014 (8)	0.0158 (7)	−0.0053 (8)
C6	0.0502 (10)	0.0429 (10)	0.0441 (9)	0.0036 (8)	0.0174 (8)	−0.0090 (8)
C7	0.0456 (10)	0.0486 (11)	0.0371 (9)	0.0021 (8)	0.0166 (7)	−0.0007 (8)
C8	0.0405 (9)	0.0358 (9)	0.0365 (8)	−0.0020 (7)	0.0111 (7)	0.0016 (7)
C8A	0.0325 (7)	0.0332 (8)	0.0343 (7)	0.0013 (6)	0.0084 (6)	−0.0006 (6)
C9	0.0464 (9)	0.0308 (8)	0.0441 (9)	−0.0048 (7)	0.0177 (7)	−0.0041 (7)
C10	0.0459 (9)	0.0392 (9)	0.0410 (9)	−0.0073 (8)	0.0163 (7)	−0.0085 (7)
C10A	0.0341 (7)	0.0334 (8)	0.0340 (7)	0.0004 (6)	0.0105 (6)	−0.0009 (6)
C11	0.0513 (11)	0.0418 (10)	0.0414 (9)	−0.0049 (8)	0.0141 (8)	0.0063 (8)
C12	0.0557 (13)	0.0660 (16)	0.0774 (17)	−0.0132 (12)	0.0109 (12)	0.0178 (13)
C13	0.089 (2)	0.0552 (15)	0.0755 (17)	−0.0051 (14)	−0.0143 (15)	0.0209 (14)
C14	0.0488 (10)	0.0403 (10)	0.0529 (11)	0.0029 (8)	0.0117 (9)	0.0112 (8)
C15	0.0601 (13)	0.0531 (12)	0.0656 (14)	0.0122 (11)	0.0343 (11)	0.0053 (11)
C16	0.0524 (11)	0.0832 (17)	0.0358 (9)	−0.0141 (12)	0.0105 (8)	−0.0057 (10)
O1	0.0843 (13)	0.0630 (11)	0.0551 (9)	−0.0062 (10)	0.0440 (9)	−0.0062 (9)
O2	0.0670 (10)	0.0661 (11)	0.0576 (9)	−0.0202 (9)	0.0293 (8)	−0.0013 (8)

Geometric parameters (Å, º)

C1—C2	1.524 (3)	C9—C10	1.513 (3)
C1—C16	1.532 (3)	C9—H9A	0.9700
C1—C15	1.544 (3)	C9—H9B	0.9700
C1—C10A	1.560 (2)	C10—C10A	1.518 (2)
C2—O2	1.219 (2)	C10—H10A	0.9700
C2—C3	1.488 (3)	C10—H10B	0.9700
C3—C4	1.515 (3)	C10A—H10	0.9800
C3—H3A	0.9700	C11—C12	1.525 (3)
C3—H3B	0.9700	C11—C13	1.526 (3)
C4—C4A	1.547 (3)	C11—H11	0.99 (4)
C4—H4A	0.9700	C12—H12A	0.9600
C4—H4B	0.9700	C12—H12B	0.9600
C4A—C14	1.532 (3)	C12—H12C	0.9600
C4A—C10A	1.539 (2)	C13—H13A	0.9600
C4A—C4B	1.541 (2)	C13—H13B	0.9600
C4B—C5	1.392 (2)	C13—H13C	0.9600
C4B—C8A	1.405 (2)	C14—H14A	0.9600
C5—C6	1.383 (3)	C14—H14B	0.9600
C5—H5	0.9300	C14—H14C	0.9600
C6—C7	1.382 (3)	C15—H15A	0.9600
C6—H6	0.9300	C15—H15B	0.9600
C7—O1	1.363 (2)	C15—H15C	0.9600
C7—C8	1.399 (3)	C16—H16A	0.9600
C8—C8A	1.419 (2)	C16—H16B	0.9600
C8—C11	1.519 (3)	C16—H16C	0.9600
C8A—C9	1.513 (2)	O1—H	0.81 (4)
C2—C1—C16	109.82 (18)	H9A—C9—H9B	107.7
C2—C1—C15	105.10 (17)	C9—C10—C10A	109.39 (15)
C16—C1—C15	108.72 (19)	C9—C10—H10A	109.8
C2—C1—C10A	110.36 (14)	C10A—C10—H10A	109.8
C16—C1—C10A	114.69 (15)	C9—C10—H10B	109.8
C15—C1—C10A	107.67 (15)	C10A—C10—H10B	109.8
O2—C2—C3	119.9 (2)	H10A—C10—H10B	108.2
O2—C2—C1	121.45 (19)	C10—C10A—C4A	110.77 (14)
C3—C2—C1	118.43 (17)	C10—C10A—C1	113.42 (14)
C2—C3—C4	118.09 (17)	C4A—C10A—C1	115.10 (14)
C2—C3—H3A	107.8	C10—C10A—H10	105.5
C4—C3—H3A	107.8	C4A—C10A—H10	105.5
C2—C3—H3B	107.8	C1—C10A—H10	105.5
C4—C3—H3B	107.8	C8—C11—C12	114.4 (2)
H3A—C3—H3B	107.1	C8—C11—C13	112.5 (2)
C3—C4—C4A	114.68 (16)	C12—C11—C13	110.5 (2)
C3—C4—H4A	108.6	C8—C11—H11	112 (2)
C4A—C4—H4A	108.6	C12—C11—H11	103.9 (17)
C3—C4—H4B	108.6	C13—C11—H11	102.5 (18)
C4A—C4—H4B	108.6	C11—C12—H12A	109.5
H4A—C4—H4B	107.6	C11—C12—H12B	109.5
C14—C4A—C10A	113.31 (15)	H12A—C12—H12B	109.5
C14—C4A—C4B	108.67 (14)	C11—C12—H12C	109.5
C10A—C4A—C4B	110.03 (13)	H12A—C12—H12C	109.5
C14—C4A—C4	109.42 (16)	H12B—C12—H12C	109.5
C10A—C4A—C4	106.51 (15)	C11—C13—H13A	109.5
C4B—C4A—C4	108.80 (14)	C11—C13—H13B	109.5
C5—C4B—C8A	118.19 (15)	H13A—C13—H13B	109.5
C5—C4B—C4A	118.32 (15)	C11—C13—H13C	109.5
C8A—C4B—C4A	123.49 (14)	H13A—C13—H13C	109.5
C6—C5—C4B	121.75 (18)	H13B—C13—H13C	109.5
C6—C5—H5	119.1	C4A—C14—H14A	109.5
C4B—C5—H5	119.1	C4A—C14—H14B	109.5
C7—C6—C5	119.62 (18)	H14A—C14—H14B	109.5
C7—C6—H6	120.2	C4A—C14—H14C	109.5
C5—C6—H6	120.2	H14A—C14—H14C	109.5
O1—C7—C6	121.19 (19)	H14B—C14—H14C	109.5
O1—C7—C8	117.43 (19)	C1—C15—H15A	109.5
C6—C7—C8	121.37 (16)	C1—C15—H15B	109.5
C7—C8—C8A	117.96 (16)	H15A—C15—H15B	109.5
C7—C8—C11	120.44 (16)	C1—C15—H15C	109.5
C8A—C8—C11	121.56 (16)	H15A—C15—H15C	109.5
C4B—C8A—C8	120.99 (15)	H15B—C15—H15C	109.5
C4B—C8A—C9	120.11 (15)	C1—C16—H16A	109.5
C8—C8A—C9	118.89 (15)	C1—C16—H16B	109.5
C10—C9—C8A	113.39 (16)	H16A—C16—H16B	109.5
C10—C9—H9A	108.9	C1—C16—H16C	109.5
C8A—C9—H9A	108.9	H16A—C16—H16C	109.5
C10—C9—H9B	108.9	H16B—C16—H16C	109.5
C8A—C9—H9B	108.9	C7—O1—H	112 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H···O2^i	0.81 (4)	2.06 (4)	2.799 (3)	152 (4)

Symmetry code: (i) x−1, y, z+1.