7-Ethenyl-1-[(Z)-hydroxy­methyl­idene]-4b,7,10a-trimethyl­perhydro­phenanthren-2-one

The title compound, C₂₀H₃₀O₂, also known as tagalsin F, is a diterpenoid which was isolated from Ceriops tagal (Perr.). One of the three fused cyclo­hexane rings adopts a half-chair conformation and the other two cyclo­hexane rings are in standard chair conformations. The hydroxy­methyl­idene substituent is attached to the half-chair cyclo­hexane. The mol­ecular structure is stabilized by intra­molecular O—H...O hydrogen bonds and weak inter­molecular C—H...O inter­actions. In the crystal structure, mol­ecules are arranged alternately in a head-to-tail and tail-to-head fashion along the b axis.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.041
• wR factor = 0.106
• Data-to-parameter ratio = 14.3

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?

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           30.00
           From the CIF: _reflns_number_total               2881
           Count of symmetry unique reflns         2883
           Completeness (_total/calc)             99.93%
           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 C5     = .          R
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C6     = .          S
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C9     = .          S
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C10    = .          S
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C13    = .          S

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

   6 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
   0 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

---

Computing details

Data collection: APEX2 (Bruker, 2005); cell refinement: APEX2; data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXTL (Sheldrick, 1998); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2003).

7-Ethenyl-1-[(Z)-hydroxymethylidene]-4 b,7,10a-trimethylperhydrophenanthren-2-one

Crystal data

C20H30O2	Dx = 1.164 Mg m^−3
Mr = 302.44	Melting point = 374–375 K
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 2631 reflections
a = 6.6826 (2) Å	θ = 1.7–30.0°
b = 10.8100 (3) Å	µ = 0.07 mm^−1
c = 23.8901 (6) Å	T = 100 K
V = 1725.79 (8) Å^3	Plate, colourless
Z = 4	0.45 × 0.22 × 0.05 mm
F(000) = 664

Data collection

Bruker SMART APEX2 CCD area-detector diffractometer	2881 independent reflections
Radiation source: fine-focus sealed tube	2631 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.047
Detector resolution: 8.33 pixels mm^-1	θmax = 30.0°, θmin = 1.7°
ω scans	h = −9→9
Absorption correction: multi-scan (SADABS; Bruker, 2005)	k = −15→15
Tmin = 0.968, Tmax = 0.996	l = −33→30
26531 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.041	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.106	H-atom parameters constrained
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0546P)^2 + 0.4474P] where P = (Fo^2 + 2Fc^2)/3
2881 reflections	(Δ/σ)max < 0.001
202 parameters	Δρmax = 0.35 e Å^−3
0 restraints	Δρmin = −0.18 e Å^−3

Special details

Experimental. The low-temparture data were collected with the Oxford Cyrosystem Cobra low-temperature attachment.

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.

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

	x	y	z	Uiso*/Ueq
O1	0.9686 (2)	0.65093 (13)	0.50805 (5)	0.0269 (3)
H1A	1.0037	0.5811	0.5173	0.040*
O2	0.9753 (2)	0.42367 (12)	0.50810 (5)	0.0235 (3)
C1	0.7583 (2)	0.53308 (15)	0.44803 (6)	0.0155 (3)
C2	0.8425 (2)	0.42193 (16)	0.46955 (7)	0.0173 (3)
C3	0.7848 (3)	0.29708 (16)	0.44753 (8)	0.0234 (4)
H3A	0.7324	0.2489	0.4785	0.028*
H3B	0.9055	0.2561	0.4346	0.028*
C4	0.6309 (3)	0.29322 (16)	0.39984 (7)	0.0220 (4)
H4A	0.5024	0.2700	0.4155	0.026*
H4B	0.6699	0.2285	0.3739	0.026*
C5	0.6032 (2)	0.41444 (15)	0.36639 (7)	0.0164 (3)
H5A	0.4718	0.4065	0.3486	0.020*
C6	0.5814 (2)	0.52544 (16)	0.40765 (6)	0.0164 (3)
C7	0.5487 (3)	0.64520 (16)	0.37398 (7)	0.0204 (3)
H7A	0.4173	0.6424	0.3568	0.024*
H7B	0.5508	0.7149	0.3995	0.024*
C8	0.7049 (3)	0.66620 (15)	0.32852 (7)	0.0196 (3)
H8A	0.8364	0.6739	0.3454	0.024*
H8B	0.6757	0.7423	0.3086	0.024*
C9	0.7032 (3)	0.55734 (14)	0.28761 (6)	0.0156 (3)
H9A	0.5654	0.5500	0.2739	0.019*
C10	0.7531 (2)	0.43318 (14)	0.31696 (6)	0.0146 (3)
C11	0.7199 (3)	0.33122 (15)	0.27275 (7)	0.0192 (3)
H11A	0.7516	0.2516	0.2892	0.023*
H11B	0.5797	0.3301	0.2622	0.023*
C12	0.8469 (3)	0.34907 (15)	0.22014 (7)	0.0197 (3)
H12A	0.8120	0.2851	0.1934	0.024*
H12B	0.9865	0.3377	0.2300	0.024*
C13	0.8234 (3)	0.47663 (16)	0.19143 (6)	0.0180 (3)
C14	0.8341 (3)	0.58054 (15)	0.23615 (6)	0.0182 (3)
H14A	0.9720	0.5896	0.2482	0.022*
H14B	0.7937	0.6580	0.2190	0.022*
C15	1.0007 (3)	0.49159 (17)	0.15239 (8)	0.0254 (4)
H15A	1.1253	0.4962	0.1696	0.030*
C16	1.0017 (4)	0.4989 (2)	0.09763 (8)	0.0363 (5)
H16A	0.8821	0.4950	0.0778	0.044*
H16B	1.1222	0.5081	0.0786	0.044*
C17	0.6233 (3)	0.48279 (18)	0.16003 (7)	0.0246 (4)
H17A	0.6173	0.4172	0.1330	0.037*
H17B	0.6123	0.5610	0.1413	0.037*
H17C	0.5152	0.4740	0.1862	0.037*
C18	0.8300 (3)	0.64333 (16)	0.46938 (7)	0.0209 (3)
H18A	0.7766	0.7166	0.4555	0.025*
C19	0.3931 (3)	0.5072 (2)	0.44407 (7)	0.0252 (4)
H19A	0.3682	0.5810	0.4653	0.038*
H19B	0.4136	0.4390	0.4691	0.038*
H19C	0.2802	0.4903	0.4204	0.038*
C20	0.9731 (2)	0.42912 (16)	0.33655 (7)	0.0189 (3)
H20A	1.0597	0.4440	0.3052	0.028*
H20B	1.0017	0.3492	0.3521	0.028*
H20C	0.9946	0.4916	0.3645	0.028*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0246 (6)	0.0290 (6)	0.0272 (6)	−0.0022 (6)	−0.0059 (6)	−0.0083 (5)
O2	0.0216 (6)	0.0299 (6)	0.0191 (5)	0.0030 (6)	−0.0066 (5)	0.0020 (5)
C1	0.0137 (7)	0.0188 (7)	0.0142 (6)	0.0005 (6)	−0.0001 (5)	−0.0004 (6)
C2	0.0159 (7)	0.0220 (7)	0.0141 (7)	−0.0001 (7)	0.0013 (6)	0.0016 (6)
C3	0.0309 (9)	0.0187 (7)	0.0207 (8)	−0.0012 (8)	−0.0033 (7)	0.0051 (6)
C4	0.0285 (9)	0.0190 (7)	0.0185 (8)	−0.0077 (7)	−0.0020 (7)	0.0031 (6)
C5	0.0144 (7)	0.0185 (7)	0.0162 (7)	−0.0035 (6)	−0.0021 (6)	0.0003 (6)
C6	0.0132 (6)	0.0220 (8)	0.0140 (7)	0.0015 (6)	−0.0008 (5)	0.0011 (6)
C7	0.0232 (8)	0.0223 (8)	0.0157 (7)	0.0085 (7)	−0.0004 (6)	−0.0009 (6)
C8	0.0277 (9)	0.0148 (7)	0.0163 (7)	0.0021 (7)	−0.0003 (6)	0.0000 (6)
C9	0.0180 (7)	0.0150 (7)	0.0140 (7)	0.0014 (6)	−0.0010 (6)	−0.0002 (5)
C10	0.0147 (7)	0.0145 (6)	0.0146 (6)	−0.0013 (6)	−0.0009 (6)	−0.0007 (5)
C11	0.0257 (8)	0.0151 (7)	0.0168 (7)	−0.0023 (7)	−0.0034 (6)	−0.0014 (6)
C12	0.0249 (8)	0.0174 (7)	0.0167 (7)	0.0019 (7)	−0.0015 (6)	−0.0032 (6)
C13	0.0223 (8)	0.0194 (7)	0.0124 (7)	−0.0019 (7)	−0.0011 (6)	−0.0009 (6)
C14	0.0234 (7)	0.0164 (7)	0.0150 (7)	−0.0023 (7)	0.0003 (6)	−0.0008 (6)
C15	0.0275 (9)	0.0257 (9)	0.0230 (8)	−0.0017 (8)	0.0028 (7)	−0.0020 (7)
C16	0.0453 (12)	0.0407 (11)	0.0228 (9)	−0.0060 (11)	0.0074 (9)	−0.0001 (8)
C17	0.0290 (9)	0.0262 (9)	0.0187 (8)	0.0014 (8)	−0.0079 (7)	0.0005 (7)
C18	0.0208 (8)	0.0206 (8)	0.0214 (8)	0.0028 (7)	0.0001 (7)	−0.0036 (6)
C19	0.0145 (7)	0.0436 (11)	0.0176 (7)	−0.0013 (8)	0.0012 (6)	−0.0006 (7)
C20	0.0155 (7)	0.0241 (8)	0.0171 (7)	0.0025 (7)	−0.0015 (6)	−0.0006 (6)

Geometric parameters (Å, º)

O1—C18	1.311 (2)	C10—C11	1.542 (2)
O1—H1A	0.8200	C10—C20	1.543 (2)
O2—C2	1.2790 (19)	C11—C12	1.529 (2)
C1—C18	1.382 (2)	C11—H11A	0.9700
C1—C2	1.423 (2)	C11—H11B	0.9700
C1—C6	1.528 (2)	C12—C13	1.548 (2)
C2—C3	1.499 (2)	C12—H12A	0.9700
C3—C4	1.536 (3)	C12—H12B	0.9700
C3—H3A	0.9700	C13—C15	1.516 (2)
C3—H3B	0.9700	C13—C17	1.534 (2)
C4—C5	1.546 (2)	C13—C14	1.552 (2)
C4—H4A	0.9700	C14—H14A	0.9700
C4—H4B	0.9700	C14—H14B	0.9700
C5—C6	1.560 (2)	C15—C16	1.311 (3)
C5—C10	1.561 (2)	C15—H15A	0.9300
C5—H5A	0.9800	C16—H16A	0.9300
C6—C7	1.540 (2)	C16—H16B	0.9300
C6—C19	1.543 (2)	C17—H17A	0.9600
C7—C8	1.523 (2)	C17—H17B	0.9600
C7—H7A	0.9700	C17—H17C	0.9600
C7—H7B	0.9700	C18—H18A	0.9300
C8—C9	1.530 (2)	C19—H19A	0.9600
C8—H8A	0.9700	C19—H19B	0.9600
C8—H8B	0.9700	C19—H19C	0.9600
C9—C14	1.530 (2)	C20—H20A	0.9600
C9—C10	1.551 (2)	C20—H20B	0.9600
C9—H9A	0.9800	C20—H20C	0.9600
C18—O1—H1A	109.5	C20—C10—C5	112.20 (12)
C18—C1—C2	117.22 (15)	C9—C10—C5	108.44 (13)
C18—C1—C6	123.22 (15)	C12—C11—C10	113.14 (14)
C2—C1—C6	119.26 (14)	C12—C11—H11A	108.9
O2—C2—C1	121.49 (15)	C10—C11—H11A	108.9
O2—C2—C3	116.39 (15)	C12—C11—H11B	108.9
C1—C2—C3	122.10 (14)	C10—C11—H11B	109.0
C2—C3—C4	117.21 (14)	H11A—C11—H11B	107.8
C2—C3—H3A	108.0	C11—C12—C13	114.86 (14)
C4—C3—H3A	108.0	C11—C12—H12A	108.6
C2—C3—H3B	108.0	C13—C12—H12A	108.6
C4—C3—H3B	108.0	C11—C12—H12B	108.6
H3A—C3—H3B	107.2	C13—C12—H12B	108.6
C3—C4—C5	116.14 (14)	H12A—C12—H12B	107.5
C3—C4—H4A	108.3	C15—C13—C17	112.06 (13)
C5—C4—H4A	108.3	C15—C13—C12	106.75 (14)
C3—C4—H4B	108.3	C17—C13—C12	110.11 (14)
C5—C4—H4B	108.3	C15—C13—C14	108.06 (14)
H4A—C4—H4B	107.4	C17—C13—C14	110.20 (14)
C4—C5—C6	109.66 (12)	C12—C13—C14	109.57 (12)
C4—C5—C10	115.11 (14)	C9—C14—C13	114.09 (13)
C6—C5—C10	115.99 (13)	C9—C14—H14A	108.7
C4—C5—H5A	104.9	C13—C14—H14A	108.7
C6—C5—H5A	104.9	C9—C14—H14B	108.7
C10—C5—H5A	104.9	C13—C14—H14B	108.7
C1—C6—C7	113.20 (14)	H14A—C14—H14B	107.6
C1—C6—C19	106.37 (12)	C16—C15—C13	128.7 (2)
C7—C6—C19	106.66 (14)	C16—C15—H15A	115.7
C1—C6—C5	111.60 (13)	C13—C15—H15A	115.7
C7—C6—C5	109.26 (12)	C15—C16—H16A	120.0
C19—C6—C5	109.55 (14)	C15—C16—H16B	120.0
C8—C7—C6	113.62 (14)	H16A—C16—H16B	120.0
C8—C7—H7A	108.8	C13—C17—H17A	109.5
C6—C7—H7A	108.8	C13—C17—H17B	109.5
C8—C7—H7B	108.8	H17A—C17—H17B	109.5
C6—C7—H7B	108.8	C13—C17—H17C	109.5
H7A—C7—H7B	107.7	H17A—C17—H17C	109.5
C7—C8—C9	109.62 (14)	H17B—C17—H17C	109.5
C7—C8—H8A	109.7	O1—C18—C1	124.00 (16)
C9—C8—H8A	109.7	O1—C18—H18A	118.0
C7—C8—H8B	109.7	C1—C18—H18A	118.0
C9—C8—H8B	109.7	C6—C19—H19A	109.5
H8A—C8—H8B	108.2	C6—C19—H19B	109.5
C8—C9—C14	112.52 (13)	H19A—C19—H19B	109.5
C8—C9—C10	112.03 (12)	C6—C19—H19C	109.5
C14—C9—C10	112.47 (13)	H19A—C19—H19C	109.5
C8—C9—H9A	106.4	H19B—C19—H19C	109.5
C14—C9—H9A	106.4	C10—C20—H20A	109.5
C10—C9—H9A	106.4	C10—C20—H20B	109.5
C11—C10—C20	108.91 (14)	H20A—C20—H20B	109.5
C11—C10—C9	106.14 (12)	C10—C20—H20C	109.5
C20—C10—C9	111.51 (14)	H20A—C20—H20C	109.5
C11—C10—C5	109.45 (13)	H20B—C20—H20C	109.5
C18—C1—C2—O2	1.8 (2)	C14—C9—C10—C11	−59.00 (17)
C6—C1—C2—O2	−172.06 (14)	C8—C9—C10—C20	−68.45 (17)
C18—C1—C2—C3	−176.69 (17)	C14—C9—C10—C20	59.47 (16)
C6—C1—C2—C3	9.5 (2)	C8—C9—C10—C5	55.57 (17)
O2—C2—C3—C4	−177.97 (15)	C14—C9—C10—C5	−176.51 (12)
C1—C2—C3—C4	0.6 (3)	C4—C5—C10—C11	63.89 (17)
C2—C3—C4—C5	19.5 (2)	C6—C5—C10—C11	−166.18 (13)
C3—C4—C5—C6	−47.1 (2)	C4—C5—C10—C20	−57.13 (18)
C3—C4—C5—C10	85.83 (18)	C6—C5—C10—C20	72.80 (18)
C18—C1—C6—C7	24.6 (2)	C4—C5—C10—C9	179.25 (13)
C2—C1—C6—C7	−161.90 (14)	C6—C5—C10—C9	−50.81 (17)
C18—C1—C6—C19	−92.17 (19)	C20—C10—C11—C12	−62.39 (17)
C2—C1—C6—C19	81.29 (19)	C9—C10—C11—C12	57.79 (18)
C18—C1—C6—C5	148.40 (16)	C5—C10—C11—C12	174.62 (14)
C2—C1—C6—C5	−38.1 (2)	C10—C11—C12—C13	−54.57 (19)
C4—C5—C6—C1	55.43 (18)	C11—C12—C13—C15	163.17 (14)
C10—C5—C6—C1	−77.07 (17)	C11—C12—C13—C17	−74.98 (17)
C4—C5—C6—C7	−178.61 (14)	C11—C12—C13—C14	46.38 (19)
C10—C5—C6—C7	48.90 (18)	C8—C9—C14—C13	−175.48 (14)
C4—C5—C6—C19	−62.11 (17)	C10—C9—C14—C13	56.86 (18)
C10—C5—C6—C19	165.40 (13)	C15—C13—C14—C9	−163.49 (14)
C1—C6—C7—C8	73.02 (17)	C17—C13—C14—C9	73.76 (17)
C19—C6—C7—C8	−170.34 (14)	C12—C13—C14—C9	−47.54 (19)
C5—C6—C7—C8	−52.01 (18)	C17—C13—C15—C16	−5.6 (3)
C6—C7—C8—C9	58.85 (18)	C12—C13—C15—C16	115.0 (2)
C7—C8—C9—C14	171.61 (14)	C14—C13—C15—C16	−127.2 (2)
C7—C8—C9—C10	−60.50 (18)	C2—C1—C18—O1	−0.4 (2)
C8—C9—C10—C11	173.08 (14)	C6—C1—C18—O1	173.20 (15)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1A···O2	0.82	1.73	2.4571 (19)	147
C3—H3A···O2^i	0.97	2.56	3.331 (2)	137

Symmetry code: (i) x−1/2, −y+1/2, −z+1.