Redetermined structure, inter-molecular inter-actions and absolute configuration of royleanone.

The structure of the title diterpenoid, C(20)H(28)O(3), {systematic name: (4bS,8aS)-3-hy-droxy-2-isopropyl-4b,8,8-trimethyl-4b,5,6,7,8,8a,9,10-octa-hydro-phenanthrene-1,4-dione} is confirmed [Eugster et al. (1993 ▶). Private communication (refcode HACGUN). CCDC, Union Road, Cambridge] and its packing is now described. Its absolute structure was established by refinement against data collected with Cu radiation: the two stereogenic centres both have S configurations. One cyclo-hexane ring adopts a chair conformation whereas the other cyclo-hexane ring is in a half-chair conformation and the benzoquinone ring is slightly twisted. An intra-molecular O-H⋯O hydrogen bond generates an S(5) ring motif. In the crystal, mol-ecules are linked into chains along [010] by O-H⋯O hydrogen bonds and weak C-H⋯O inter-actions. The packing also features C⋯O [3.131 (3) Å] short contacts.

Related literature

For the previous determination of the title structure, see: Eugster et al. (1993 ▶). For ring conformations, see: Cremer & Pople (1975 ▶). For bond-length data, see: Allen et al. (1987 ▶). For background to Verbenaceae plants and the bioactivity of diterpenoids, see: Bunluepuech & Tewtrakul (2009 ▶); Edwards et al. (1962 ▶); Kabouche et al. (2007 ▶); Suresh et al. (2011 ▶); Slamenová et al. (2004 ▶); Tezuka et al. (1998 ▶). For a related structure, see: Razak et al. (2010 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995) ▶. For the stability of the temperature controller used in the data collection, see Cosier & Glazer, (1986 ▶).

Experimental

Crystal data

C20H28O3

M = 316.42

Monoclinic,

a = 10.2247 (2) Å

b = 7.6353 (1) Å

c = 10.7292 (2) Å

β = 97.992 (1)°

V = 829.48 (2) Å3

Z = 2

Cu Kα radiation

μ = 0.66 mm−1

T = 100 K

0.52 × 0.31 × 0.15 mm

Data collection

Bruker APEX DUO CCD diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T min = 0.726, T max = 0.909

5901 measured reflections

2390 independent reflections

2375 reflections with I > 2σ(I)

R int = 0.021

Refinement

R[F 2 > 2σ(F 2)] = 0.036

wR(F 2) = 0.098

S = 1.06

2390 reflections

217 parameters

1 restraint

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.35 e Å−3

Δρmin = −0.20 e Å−3

Absolute structure: Flack (1983 ▶) 699 Friedel pairs

Flack parameter: 0.11 (19)

Data collection: APEX2 (Bruker, 2009) ▶; cell refinement: SAINT (Bruker, 2009) ▶; data reduction: SAINT ▶; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL (Sheldrick, 2008 ▶) and PLATON (Spek, 2009 ▶).

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536811011457/hb5812sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811011457/hb5812Isup2.hkl

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

C20H28O3	F(000) = 344
Mr = 316.42	Dx = 1.267 Mg m−3
Monoclinic, P21	Melting point = 451–453 K
Hall symbol: P 2yb	Cu Kα radiation, λ = 1.54178 Å
a = 10.2247 (2) Å	Cell parameters from 2390 reflections
b = 7.6353 (1) Å	θ = 5.6–72.1°
c = 10.7292 (2) Å	µ = 0.66 mm−1
β = 97.992 (1)°	T = 100 K
V = 829.48 (2) Å3	Block, yellow
Z = 2	0.52 × 0.31 × 0.15 mm

Bruker APEX Duo CCD diffractometer	2390 independent reflections
Radiation source: sealed tube	2375 reflections with I > 2σ(I)
graphite	Rint = 0.021
φ and ω scans	θmax = 72.1°, θmin = 5.6°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −12→12
Tmin = 0.726, Tmax = 0.909	k = −9→6
5901 measured reflections	l = −13→12

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)] = 0.036	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.098	w = 1/[σ2(Fo2) + (0.0639P)2 + 0.2006P] where P = (Fo2 + 2Fc2)/3
S = 1.06	(Δ/σ)max = 0.001
2390 reflections	Δρmax = 0.35 e Å−3
217 parameters	Δρmin = −0.20 e Å−3
1 restraint	Absolute structure: Flack (1983) 699 Friedel pairs
Primary atom site location: structure-invariant direct methods	Flack parameter: 0.11 (19)

Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K.

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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	0.64538 (13)	−0.0889 (2)	0.48735 (12)	0.0254 (3)
O2	0.54777 (12)	−0.05136 (18)	0.25211 (12)	0.0219 (3)
H1O2	0.567 (3)	−0.139 (5)	0.304 (3)	0.055 (9)*
O3	0.59784 (11)	0.55637 (18)	0.31995 (11)	0.0202 (3)
C1	0.91254 (18)	0.0149 (3)	0.61639 (17)	0.0244 (4)
H1A	0.8633	−0.0932	0.6003	0.029*
H1B	0.9513	0.0438	0.5414	0.029*
C2	1.02342 (19)	−0.0129 (3)	0.72689 (19)	0.0293 (4)
H2A	0.9853	−0.0529	0.7997	0.035*
H2B	1.0828	−0.1033	0.7048	0.035*
C3	1.10107 (17)	0.1532 (3)	0.76032 (17)	0.0258 (5)
H3A	1.1496	0.1824	0.6916	0.031*
H3B	1.1652	0.1310	0.8341	0.031*
C4	1.01699 (15)	0.3115 (3)	0.78684 (15)	0.0194 (4)
C5	0.90137 (15)	0.3285 (3)	0.67650 (14)	0.0181 (4)
H5A	0.9442	0.3520	0.6020	0.022*
C6	0.80962 (18)	0.4855 (3)	0.68588 (18)	0.0264 (4)
H6A	0.7458	0.4577	0.7419	0.032*
H6B	0.8607	0.5859	0.7199	0.032*
C7	0.73866 (16)	0.5283 (3)	0.55608 (16)	0.0194 (4)
H7A	0.6623	0.6004	0.5646	0.023*
H7B	0.7972	0.5959	0.5108	0.023*
C8	0.69435 (15)	0.3689 (2)	0.48092 (15)	0.0155 (4)
C9	0.72317 (14)	0.2047 (2)	0.52206 (14)	0.0153 (4)
C10	0.81709 (15)	0.1624 (2)	0.64288 (14)	0.0153 (3)
C11	0.65384 (15)	0.0604 (3)	0.44783 (15)	0.0174 (4)
C12	0.58810 (16)	0.0954 (3)	0.31623 (15)	0.0175 (4)
C13	0.57151 (15)	0.2572 (3)	0.26820 (15)	0.0165 (4)
C14	0.61740 (15)	0.4041 (3)	0.35330 (15)	0.0156 (3)
C15	0.51364 (15)	0.3012 (3)	0.13372 (14)	0.0184 (4)
H15A	0.5037	0.4287	0.1280	0.022*
C16	0.61027 (18)	0.2461 (3)	0.04345 (16)	0.0260 (4)
H16A	0.6936	0.3034	0.0671	0.039*
H16B	0.5750	0.2790	−0.0409	0.039*
H16C	0.6226	0.1215	0.0477	0.039*
C17	0.37759 (17)	0.2199 (3)	0.09225 (18)	0.0262 (4)
H17A	0.3187	0.2518	0.1508	0.039*
H17B	0.3856	0.0947	0.0900	0.039*
H17C	0.3431	0.2621	0.0099	0.039*
C18	1.10451 (18)	0.4757 (3)	0.78830 (19)	0.0294 (5)
H18A	1.1833	0.4592	0.8472	0.044*
H18B	1.0570	0.5755	0.8129	0.044*
H18C	1.1279	0.4948	0.7058	0.044*
C19	0.97379 (18)	0.2988 (3)	0.91827 (15)	0.0266 (4)
H19A	1.0493	0.3138	0.9813	0.040*
H19B	0.9350	0.1860	0.9281	0.040*
H19C	0.9101	0.3886	0.9274	0.040*
C20	0.73179 (17)	0.1029 (3)	0.74287 (16)	0.0265 (4)
H20A	0.6730	0.0115	0.7087	0.040*
H20B	0.6813	0.2003	0.7666	0.040*
H20C	0.7880	0.0598	0.8155	0.040*

	U11	U22	U33	U12	U13	U23
O1	0.0347 (7)	0.0149 (7)	0.0236 (6)	−0.0044 (6)	−0.0064 (5)	0.0030 (5)
O2	0.0283 (6)	0.0142 (8)	0.0208 (6)	−0.0021 (5)	−0.0050 (5)	−0.0011 (5)
O3	0.0217 (6)	0.0152 (7)	0.0221 (6)	−0.0003 (5)	−0.0024 (4)	0.0026 (5)
C1	0.0284 (8)	0.0194 (11)	0.0228 (8)	0.0053 (8)	−0.0062 (7)	−0.0049 (7)
C2	0.0307 (9)	0.0224 (11)	0.0313 (10)	0.0092 (9)	−0.0082 (7)	−0.0048 (9)
C3	0.0194 (8)	0.0331 (13)	0.0227 (8)	0.0065 (8)	−0.0046 (6)	−0.0044 (8)
C4	0.0183 (7)	0.0220 (11)	0.0169 (7)	−0.0007 (8)	−0.0006 (6)	−0.0001 (7)
C5	0.0189 (7)	0.0198 (10)	0.0152 (7)	−0.0025 (7)	0.0009 (6)	0.0001 (7)
C6	0.0310 (9)	0.0199 (10)	0.0258 (9)	0.0003 (8)	−0.0055 (7)	−0.0054 (8)
C7	0.0224 (7)	0.0148 (10)	0.0207 (8)	−0.0005 (7)	0.0016 (6)	−0.0011 (7)
C8	0.0143 (7)	0.0157 (10)	0.0163 (7)	−0.0009 (6)	0.0020 (6)	−0.0002 (6)
C9	0.0147 (6)	0.0167 (10)	0.0145 (7)	−0.0008 (6)	0.0020 (5)	−0.0005 (6)
C10	0.0172 (7)	0.0158 (9)	0.0124 (7)	−0.0013 (7)	0.0005 (6)	0.0006 (6)
C11	0.0177 (7)	0.0158 (10)	0.0182 (7)	0.0007 (7)	0.0015 (6)	0.0008 (7)
C12	0.0176 (7)	0.0167 (11)	0.0178 (8)	−0.0011 (7)	0.0016 (6)	−0.0020 (7)
C13	0.0141 (7)	0.0179 (10)	0.0170 (8)	0.0000 (6)	0.0004 (6)	−0.0003 (7)
C14	0.0132 (6)	0.0157 (9)	0.0181 (7)	0.0007 (6)	0.0029 (6)	−0.0001 (7)
C15	0.0220 (7)	0.0160 (10)	0.0161 (7)	0.0003 (7)	−0.0016 (6)	0.0009 (7)
C16	0.0301 (9)	0.0294 (12)	0.0181 (8)	0.0049 (8)	0.0020 (6)	0.0026 (7)
C17	0.0224 (8)	0.0256 (11)	0.0277 (8)	0.0000 (8)	−0.0065 (6)	−0.0001 (8)
C18	0.0268 (9)	0.0307 (12)	0.0281 (9)	−0.0091 (9)	−0.0056 (7)	0.0027 (9)
C19	0.0277 (8)	0.0341 (12)	0.0167 (8)	−0.0016 (8)	−0.0013 (6)	−0.0050 (8)
C20	0.0225 (8)	0.0388 (13)	0.0181 (8)	−0.0087 (8)	0.0020 (6)	0.0034 (8)

O1—C11	1.224 (2)	C8—C14	1.506 (2)
O2—C12	1.349 (2)	C9—C11	1.481 (2)
O2—H1O2	0.88 (4)	C9—C10	1.536 (2)
O3—C14	1.225 (2)	C10—C20	1.542 (2)
C1—C2	1.537 (2)	C11—C12	1.501 (2)
C1—C10	1.542 (2)	C12—C13	1.341 (3)
C1—H1A	0.9700	C13—C14	1.481 (3)
C1—H1B	0.9700	C13—C15	1.519 (2)
C2—C3	1.513 (3)	C15—C17	1.532 (2)
C2—H2A	0.9700	C15—C16	1.535 (2)
C2—H2B	0.9700	C15—H15A	0.9800
C3—C4	1.533 (3)	C16—H16A	0.9600
C3—H3A	0.9700	C16—H16B	0.9600
C3—H3B	0.9700	C16—H16C	0.9600
C4—C19	1.538 (2)	C17—H17A	0.9600
C4—C18	1.539 (3)	C17—H17B	0.9600
C4—C5	1.558 (2)	C17—H17C	0.9600
C5—C6	1.534 (3)	C18—H18A	0.9600
C5—C10	1.548 (3)	C18—H18B	0.9600
C5—H5A	0.9800	C18—H18C	0.9600
C6—C7	1.514 (2)	C19—H19A	0.9600
C6—H6A	0.9700	C19—H19B	0.9600
C6—H6B	0.9700	C19—H19C	0.9600
C7—C8	1.495 (2)	C20—H20A	0.9600
C7—H7A	0.9700	C20—H20B	0.9600
C7—H7B	0.9700	C20—H20C	0.9600
C8—C9	1.348 (3)
C12—O2—H1O2	107 (2)	C9—C10—C5	106.69 (14)
C2—C1—C10	112.12 (15)	C20—C10—C5	115.45 (14)
C2—C1—H1A	109.2	C1—C10—C5	107.17 (13)
C10—C1—H1A	109.2	O1—C11—C9	123.94 (15)
C2—C1—H1B	109.2	O1—C11—C12	116.59 (16)
C10—C1—H1B	109.2	C9—C11—C12	119.46 (16)
H1A—C1—H1B	107.9	C13—C12—O2	123.80 (15)
C3—C2—C1	111.93 (18)	C13—C12—C11	122.80 (16)
C3—C2—H2A	109.2	O2—C12—C11	113.40 (16)
C1—C2—H2A	109.2	C12—C13—C14	116.67 (14)
C3—C2—H2B	109.2	C12—C13—C15	125.48 (17)
C1—C2—H2B	109.2	C14—C13—C15	117.82 (16)
H2A—C2—H2B	107.9	O3—C14—C13	120.92 (15)
C2—C3—C4	114.57 (15)	O3—C14—C8	118.62 (15)
C2—C3—H3A	108.6	C13—C14—C8	120.41 (16)
C4—C3—H3A	108.6	C13—C15—C17	113.86 (15)
C2—C3—H3B	108.6	C13—C15—C16	109.82 (14)
C4—C3—H3B	108.6	C17—C15—C16	110.11 (15)
H3A—C3—H3B	107.6	C13—C15—H15A	107.6
C3—C4—C19	111.12 (16)	C17—C15—H15A	107.6
C3—C4—C18	107.69 (15)	C16—C15—H15A	107.6
C19—C4—C18	106.43 (16)	C15—C16—H16A	109.5
C3—C4—C5	108.09 (14)	C15—C16—H16B	109.5
C19—C4—C5	114.68 (13)	H16A—C16—H16B	109.5
C18—C4—C5	108.58 (15)	C15—C16—H16C	109.5
C6—C5—C10	109.26 (13)	H16A—C16—H16C	109.5
C6—C5—C4	114.94 (15)	H16B—C16—H16C	109.5
C10—C5—C4	116.62 (16)	C15—C17—H17A	109.5
C6—C5—H5A	104.9	C15—C17—H17B	109.5
C10—C5—H5A	104.9	H17A—C17—H17B	109.5
C4—C5—H5A	104.9	C15—C17—H17C	109.5
C7—C6—C5	109.12 (15)	H17A—C17—H17C	109.5
C7—C6—H6A	109.9	H17B—C17—H17C	109.5
C5—C6—H6A	109.9	C4—C18—H18A	109.5
C7—C6—H6B	109.9	C4—C18—H18B	109.5
C5—C6—H6B	109.9	H18A—C18—H18B	109.5
H6A—C6—H6B	108.3	C4—C18—H18C	109.5
C8—C7—C6	113.02 (17)	H18A—C18—H18C	109.5
C8—C7—H7A	109.0	H18B—C18—H18C	109.5
C6—C7—H7A	109.0	C4—C19—H19A	109.5
C8—C7—H7B	109.0	C4—C19—H19B	109.5
C6—C7—H7B	109.0	H19A—C19—H19B	109.5
H7A—C7—H7B	107.8	C4—C19—H19C	109.5
C9—C8—C7	122.99 (14)	H19A—C19—H19C	109.5
C9—C8—C14	121.79 (15)	H19B—C19—H19C	109.5
C7—C8—C14	115.20 (15)	C10—C20—H20A	109.5
C8—C9—C11	116.69 (14)	C10—C20—H20B	109.5
C8—C9—C10	123.65 (15)	H20A—C20—H20B	109.5
C11—C9—C10	119.60 (16)	C10—C20—H20C	109.5
C9—C10—C20	107.53 (12)	H20A—C20—H20C	109.5
C9—C10—C1	109.58 (13)	H20B—C20—H20C	109.5
C20—C10—C1	110.27 (16)
C10—C1—C2—C3	−56.7 (2)	C4—C5—C10—C9	−172.64 (13)
C1—C2—C3—C4	54.2 (2)	C6—C5—C10—C20	−64.48 (19)
C2—C3—C4—C19	76.8 (2)	C4—C5—C10—C20	67.96 (19)
C2—C3—C4—C18	−167.00 (15)	C6—C5—C10—C1	172.24 (13)
C2—C3—C4—C5	−49.9 (2)	C4—C5—C10—C1	−55.33 (17)
C3—C4—C5—C6	−177.96 (16)	C8—C9—C11—O1	−162.38 (16)
C19—C4—C5—C6	57.5 (2)	C10—C9—C11—O1	14.7 (2)
C18—C4—C5—C6	−61.40 (19)	C8—C9—C11—C12	17.2 (2)
C3—C4—C5—C10	52.25 (18)	C10—C9—C11—C12	−165.74 (13)
C19—C4—C5—C10	−72.3 (2)	O1—C11—C12—C13	169.20 (16)
C18—C4—C5—C10	168.81 (14)	C9—C11—C12—C13	−10.4 (2)
C10—C5—C6—C7	−68.58 (19)	O1—C11—C12—O2	−10.7 (2)
C4—C5—C6—C7	158.12 (15)	C9—C11—C12—O2	169.71 (14)
C5—C6—C7—C8	40.90 (19)	O2—C12—C13—C14	177.82 (14)
C6—C7—C8—C9	−4.3 (2)	C11—C12—C13—C14	−2.1 (2)
C6—C7—C8—C14	177.17 (14)	O2—C12—C13—C15	−4.1 (2)
C7—C8—C9—C11	169.78 (13)	C11—C12—C13—C15	176.03 (14)
C14—C8—C9—C11	−11.8 (2)	C12—C13—C14—O3	−174.92 (15)
C7—C8—C9—C10	−7.2 (2)	C15—C13—C14—O3	6.8 (2)
C14—C8—C9—C10	171.21 (13)	C12—C13—C14—C8	7.7 (2)
C8—C9—C10—C20	105.79 (19)	C15—C13—C14—C8	−170.58 (13)
C11—C9—C10—C20	−71.10 (19)	C9—C8—C14—O3	−177.84 (15)
C8—C9—C10—C1	−134.34 (17)	C7—C8—C14—O3	0.68 (19)
C11—C9—C10—C1	48.77 (19)	C9—C8—C14—C13	−0.4 (2)
C8—C9—C10—C5	−18.63 (19)	C7—C8—C14—C13	178.12 (13)
C11—C9—C10—C5	164.48 (13)	C12—C13—C15—C17	54.2 (2)
C2—C1—C10—C9	170.62 (16)	C14—C13—C15—C17	−127.68 (17)
C2—C1—C10—C20	−71.2 (2)	C12—C13—C15—C16	−69.8 (2)
C2—C1—C10—C5	55.2 (2)	C14—C13—C15—C16	108.33 (18)
C6—C5—C10—C9	54.93 (16)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H1O2···O1	0.88 (4)	2.05 (3)	2.5977 (18)	119 (3)
O2—H1O2···O3i	0.88 (4)	2.35 (4)	3.1079 (19)	145 (3)
C1—H1A···O1	0.97	2.38	2.993 (2)	120
C7—H7A···O1ii	0.97	2.51	3.131 (3)	122
C17—H17B···O2	0.96	2.49	3.071 (2)	119
C20—H20A···O1	0.96	2.47	3.125 (2)	125

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H1O2⋯O1	0.88 (4)	2.05 (3)	2.5977 (18)	119 (3)
O2—H1O2⋯O3i	0.88 (4)	2.35 (4)	3.1079 (19)	145 (3)
C1—H1A⋯O1	0.97	2.38	2.993 (2)	120
C7—H7A⋯O1ii	0.97	2.51	3.131 (3)	122
C17—H17B⋯O2	0.96	2.49	3.071 (2)	119
C20—H20A⋯O1	0.96	2.47	3.125 (2)	125

Symmetry codes: (i) ; (ii) .