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Acta Crystallogr Sect E Struct Rep Online. 2010 November 1; 66(Pt 11): o2899.
Published online 2010 October 23. doi:  10.1107/S160053681004208X
PMCID: PMC3009237

6α-Hy­droxy-5,6-dihydro­salviasperanol

Abstract

In the title compound, C20H28O4, a diterpenoid isolated from the roots of Premna obtusifolia (Verbenaceae), the five-membered ring is in a half-chair conformation. One six-membered ring exists in a twisted-boat conformation while the other is in half-boat conformation. The crystal packing is stabilized by inter­molecular O—H(...)O and weak C—H(...)O inter­actions, generating (001) sheets.

Related literature

For background to Verbenaceae, diterpenes and their bio­log­ical activity, see: Hymavathi et al. (2009 [triangle]); Bunluepuech & Tewtrakul (2009 [triangle]); Esquivel et al. (1995 [triangle]). For ring conformations and ring puckering analysis, see: Cremer & Pople (1975 [triangle]). For bond-length data, see: Allen et al. (1987 [triangle]). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 [triangle]).

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Object name is e-66-o2899-scheme1.jpg

Experimental

Crystal data

  • C20H28O4
  • M r = 332.42
  • Orthorhombic, An external file that holds a picture, illustration, etc.
Object name is e-66-o2899-efi1.jpg
  • a = 6.2767 (2) Å
  • b = 11.7358 (4) Å
  • c = 23.7496 (7) Å
  • V = 1749.45 (10) Å3
  • Z = 4
  • Mo Kα radiation
  • μ = 0.09 mm−1
  • T = 100 K
  • 0.49 × 0.36 × 0.24 mm

Data collection

  • Bruker SMART APEXII CCD area-detector diffractometer
  • Absorption correction: multi-scan (SADABS; Bruker, 2005) T min = 0.959, T max = 0.979
  • 15028 measured reflections
  • 3534 independent reflections
  • 3079 reflections with I > 2σ(I)
  • R int = 0.037

Refinement

  • R[F 2 > 2σ(F 2)] = 0.041
  • wR(F 2) = 0.107
  • S = 1.15
  • 3534 reflections
  • 233 parameters
  • H atoms treated by a mixture of independent and constrained refinement
  • Δρmax = 0.36 e Å−3
  • Δρmin = −0.25 e Å−3

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

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053681004208X/hb5689sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S160053681004208X/hb5689Isup2.hkl

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

Acknowledgments

SIJA, IAR and HKF thank Universiti Sains Malaysia for the Research University Grant (No.1001/PFIZIK/811151). SC thanks the Prince of Songkla University for generous support through the Crystal Materials Research Unit.

supplementary crystallographic information

Comment

Plants of the family Verbenaceae were found to possess interesting biological properties such as cytotoxicity (Hymavathi et al., 2009) and anti-HIV-1 integrase activities (Bunluepuech & Tewtrakul, 2009). The phytochemistry study of the aerial parts of Premna obtusifolia (Verbenaceae), a small tree found in the mangrove forests which were collected from Satun province in the southern part of Thailand, led to the isolation of diterpenes. The title compound which is known as 5,6-dihydro-6α-hydroxysalviasperanol (Esquivel et al., 1995) is one of the isolated compounds from this plant. Herein we report the crystal structure of the title compound (I).

The bond lengths show normal values (Allen et al., 1987). The pyrocatechol, C8/C9/C11–C14/O3/O4, is planar with the maximum deviation of 0.006Å for atom C12. The five-membered ring, C5–C7/C10/O1, is in half-chair conformation with the puckering parameter Q = 0.4588 (16)Å, [var phi] = 194.0 (2)°. The six-membered ring, C1–C5/C10 adopts twisted-boat conformation with puckering parameter Q = 0.6536 (18)Å, θ = 79.56 (16)° and [var phi] = 156.60 (16)°. The other six-membered ring , C7–C10/C20/O1, is in half-boat conformation with puckering parameter Q = 0.5929 (15)Å, θ = 47.83 (15)° and [var phi] = 347.9 (2)° (Cremer & Pople 1975). The torsion angles of propanyl group attached to the pyrocatechol ring are C14–C13–C15–C17 = -101.80 (19)° and C14–C13–C15–C16 = 78.55 (19)°.

The crystal packing of (I) is stabilized by intermolecular O3—H1O3···O2 and O4—H1O4···O1 and weak C18—H18B···O3 interactions. The molecules are linked into infinite two dimensional networks parallel to ab plane.

Experimental

The air-dried roots of Premna obtusifolia (4.5 kg) were extracted with CH2Cl2 (2 x 20 L) under room temperature. The combined extracts were concentrated under reduced pressure to give a dark yellow extract (40.5g) which was subjected to quick column chromatography (QCC) over silicagel using solvents of increasing polarity from n–hexane to EtOAc to afford 12 fractions (F1–F12). Fraction F10 was further purified by QCC using CH2Cl2–EtOAc (3:7), yielding compound (I) (145.8 mg). Colorless block-shaped single crystals of (I) were recrystallized from CH2Cl2 after several days (m.p.461–463 K).

Refinement

Anomalous dispersion was negligible and Friedel pairs were merged before refinement. O bound H atoms were located from the difference map and isotropically refined.The remaining H atoms were placed in calculated positions with (C—H) = 0.98 for CH, 0.97 for CH2, 0.96 for CH3 and 0.93 Å for CH in benzene group. The Uiso values were constrained to be 1.5Ueq of the carrier atom for methyl H atoms and 1.2Ueq for the remaining H atoms. A rotating group model was used for the methyl groups.

Figures

Fig. 1.
The structure of (I), showing 50% probability displacement ellipsoids.
Fig. 2.
The crystal packing of (I) viewed along the a axis, showing infinite two dimensional networks parallel to ab plane. Hydrogen bonds are shown as dashed lines.

Crystal data

C20H28O4F(000) = 720
Mr = 332.42Dx = 1.262 Mg m3
Orthorhombic, P212121Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2abCell parameters from 6222 reflections
a = 6.2767 (2) Åθ = 2.4–32.3°
b = 11.7358 (4) ŵ = 0.09 mm1
c = 23.7496 (7) ÅT = 100 K
V = 1749.45 (10) Å3Block, colourless
Z = 40.49 × 0.36 × 0.24 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer3534 independent reflections
Radiation source: sealed tube3079 reflections with I > 2σ(I)
graphiteRint = 0.037
[var phi] and ω scansθmax = 32.4°, θmin = 2.4°
Absorption correction: multi-scan (SADABS; Bruker, 2005)h = −8→9
Tmin = 0.959, Tmax = 0.979k = −17→16
15028 measured reflectionsl = −34→35

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.041Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.107H atoms treated by a mixture of independent and constrained refinement
S = 1.15w = 1/[σ2(Fo2) + (0.0548P)2 + 0.2019P] where P = (Fo2 + 2Fc2)/3
3534 reflections(Δ/σ)max < 0.001
233 parametersΔρmax = 0.36 e Å3
0 restraintsΔρmin = −0.25 e Å3

Special details

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)

xyzUiso*/Ueq
O10.7000 (2)0.51248 (9)0.29871 (5)0.0162 (2)
O20.3927 (2)0.76867 (10)0.28241 (5)0.0179 (2)
H1O20.295 (4)0.730 (2)0.2677 (10)0.035 (7)*
O3−0.1349 (2)0.42654 (11)0.15694 (5)0.0212 (3)
H1O3−0.199 (5)0.379 (2)0.1782 (10)0.036 (7)*
O4−0.0204 (2)0.35135 (9)0.26393 (5)0.0175 (2)
H1O4−0.122 (5)0.391 (2)0.2762 (10)0.034 (7)*
C10.6494 (3)0.43356 (13)0.39056 (7)0.0193 (3)
H1A0.72020.36760.37460.023*
H1B0.54070.40580.41620.023*
C20.8142 (3)0.50212 (15)0.42483 (7)0.0231 (3)
H2A0.80180.48110.46420.028*
H2B0.95600.48110.41240.028*
C30.7889 (3)0.63252 (15)0.41961 (7)0.0200 (3)
H3A0.84830.66840.45290.024*
H3B0.86990.65880.38730.024*
C40.5563 (3)0.67027 (13)0.41290 (6)0.0162 (3)
C50.4707 (3)0.62326 (12)0.35629 (6)0.0141 (3)
H5A0.31470.62570.35740.017*
C60.5467 (3)0.69065 (12)0.30370 (6)0.0141 (3)
H6A0.67530.73340.31380.017*
C70.6093 (3)0.59624 (12)0.26148 (6)0.0146 (3)
H7A0.71520.62390.23440.018*
C80.4169 (3)0.54859 (12)0.23181 (6)0.0145 (3)
C90.2902 (3)0.47081 (12)0.26130 (6)0.0144 (3)
C100.5406 (3)0.49841 (12)0.34320 (6)0.0147 (3)
C110.1059 (3)0.43033 (12)0.23603 (6)0.0145 (3)
C120.0464 (3)0.46583 (13)0.18190 (6)0.0155 (3)
C130.1739 (3)0.54262 (13)0.15161 (6)0.0161 (3)
C140.3583 (3)0.58331 (12)0.17780 (6)0.0154 (3)
H14A0.44430.63500.15870.018*
C150.1063 (3)0.57665 (14)0.09244 (6)0.0196 (3)
H15A0.04680.50850.07450.023*
C160.2922 (3)0.61702 (16)0.05555 (7)0.0237 (4)
H16A0.24310.62810.01770.036*
H16B0.40300.56060.05590.036*
H16C0.34680.68760.07000.036*
C17−0.0714 (3)0.66608 (18)0.09427 (8)0.0286 (4)
H17A−0.19050.63640.11500.043*
H17B−0.11530.68410.05660.043*
H17C−0.01970.73380.11240.043*
C180.5432 (3)0.80127 (14)0.41448 (7)0.0205 (3)
H18A0.58620.82800.45100.031*
H18B0.39940.82480.40720.031*
H18C0.63590.83260.38630.031*
C190.4188 (3)0.62608 (15)0.46181 (6)0.0213 (3)
H19A0.47980.65010.49690.032*
H19B0.41360.54440.46060.032*
H19C0.27710.65610.45850.032*
C200.3572 (3)0.42821 (12)0.31863 (6)0.0158 (3)
H20A0.40120.34920.31560.019*
H20B0.23630.43160.34400.019*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
O10.0152 (6)0.0138 (5)0.0197 (5)0.0030 (4)0.0026 (4)0.0022 (4)
O20.0206 (6)0.0119 (5)0.0213 (5)0.0033 (5)−0.0016 (5)0.0015 (4)
O30.0204 (7)0.0206 (5)0.0226 (5)−0.0081 (5)−0.0026 (5)0.0026 (4)
O40.0182 (6)0.0109 (5)0.0234 (5)−0.0024 (4)0.0037 (5)0.0006 (4)
C10.0231 (9)0.0138 (6)0.0211 (6)0.0039 (6)−0.0016 (6)0.0029 (5)
C20.0221 (9)0.0215 (8)0.0257 (7)0.0055 (7)−0.0053 (7)0.0015 (6)
C30.0194 (8)0.0193 (7)0.0214 (7)−0.0001 (7)−0.0029 (6)−0.0001 (6)
C40.0188 (8)0.0126 (6)0.0173 (6)−0.0004 (6)−0.0016 (6)0.0002 (5)
C50.0145 (7)0.0107 (6)0.0171 (6)0.0005 (6)0.0002 (5)0.0004 (5)
C60.0144 (7)0.0111 (6)0.0168 (6)0.0006 (6)−0.0005 (5)−0.0001 (5)
C70.0153 (7)0.0120 (6)0.0165 (6)0.0000 (6)0.0008 (5)0.0015 (5)
C80.0147 (8)0.0115 (6)0.0174 (6)0.0003 (5)0.0014 (5)−0.0010 (5)
C90.0162 (7)0.0102 (6)0.0168 (6)0.0009 (5)0.0023 (6)−0.0011 (5)
C100.0139 (7)0.0122 (6)0.0180 (6)0.0007 (6)0.0007 (5)0.0013 (5)
C110.0161 (7)0.0086 (5)0.0189 (6)−0.0002 (5)0.0037 (5)−0.0002 (5)
C120.0146 (8)0.0120 (6)0.0198 (6)−0.0009 (6)0.0003 (6)−0.0019 (5)
C130.0184 (8)0.0130 (6)0.0168 (6)0.0008 (6)0.0011 (6)−0.0012 (5)
C140.0169 (8)0.0118 (6)0.0174 (6)−0.0009 (6)0.0027 (5)−0.0009 (5)
C150.0236 (9)0.0180 (7)0.0171 (6)−0.0057 (7)−0.0017 (6)0.0002 (5)
C160.0324 (10)0.0202 (7)0.0186 (6)−0.0058 (8)0.0027 (7)−0.0002 (6)
C170.0235 (10)0.0304 (9)0.0318 (8)0.0020 (8)−0.0039 (7)0.0089 (7)
C180.0269 (9)0.0144 (6)0.0203 (6)0.0009 (7)−0.0026 (7)−0.0020 (5)
C190.0262 (9)0.0206 (7)0.0171 (6)0.0005 (7)0.0028 (6)0.0013 (6)
C200.0193 (8)0.0100 (6)0.0181 (6)−0.0015 (6)0.0011 (6)0.0006 (5)

Geometric parameters (Å, °)

O1—C71.4395 (18)C8—C141.395 (2)
O1—C101.4647 (19)C8—C91.399 (2)
O2—C61.4244 (19)C9—C111.387 (2)
O2—H1O20.84 (3)C9—C201.510 (2)
O3—C121.363 (2)C10—C201.531 (2)
O3—H1O30.85 (3)C11—C121.402 (2)
O4—C111.3882 (18)C12—C131.404 (2)
O4—H1O40.84 (3)C13—C141.398 (2)
C1—C101.520 (2)C13—C151.521 (2)
C1—C21.543 (3)C14—H14A0.9300
C1—H1A0.9700C15—C171.532 (3)
C1—H1B0.9700C15—C161.534 (2)
C2—C31.544 (2)C15—H15A0.9800
C2—H2A0.9700C16—H16A0.9600
C2—H2B0.9700C16—H16B0.9600
C3—C41.535 (3)C16—H16C0.9600
C3—H3A0.9700C17—H17A0.9600
C3—H3B0.9700C17—H17B0.9600
C4—C191.537 (2)C17—H17C0.9600
C4—C181.540 (2)C18—H18A0.9600
C4—C51.549 (2)C18—H18B0.9600
C5—C61.553 (2)C18—H18C0.9600
C5—C101.561 (2)C19—H19A0.9600
C5—H5A0.9800C19—H19B0.9600
C6—C71.545 (2)C19—H19C0.9600
C6—H6A0.9800C20—H20A0.9700
C7—C81.506 (2)C20—H20B0.9700
C7—H7A0.9800
C7—O1—C10104.47 (12)O1—C10—C20107.42 (12)
C6—O2—H1O2107.5 (18)C1—C10—C20110.51 (12)
C12—O3—H1O3110.8 (18)O1—C10—C5103.28 (11)
C11—O4—H1O4103.5 (18)C1—C10—C5116.68 (12)
C10—C1—C2115.50 (13)C20—C10—C5111.72 (13)
C10—C1—H1A108.4C9—C11—O4119.91 (13)
C2—C1—H1A108.4C9—C11—C12121.15 (14)
C10—C1—H1B108.4O4—C11—C12118.93 (14)
C2—C1—H1B108.4O3—C12—C11121.38 (14)
H1A—C1—H1B107.5O3—C12—C13118.05 (13)
C3—C2—C1113.94 (14)C11—C12—C13120.57 (15)
C3—C2—H2A108.8C14—C13—C12117.61 (14)
C1—C2—H2A108.8C14—C13—C15123.51 (14)
C3—C2—H2B108.8C12—C13—C15118.88 (15)
C1—C2—H2B108.8C8—C14—C13121.84 (14)
H2A—C2—H2B107.7C8—C14—H14A119.1
C4—C3—C2113.11 (15)C13—C14—H14A119.1
C4—C3—H3A109.0C13—C15—C17110.89 (14)
C2—C3—H3A109.0C13—C15—C16113.37 (15)
C4—C3—H3B109.0C17—C15—C16111.00 (15)
C2—C3—H3B109.0C13—C15—H15A107.1
H3A—C3—H3B107.8C17—C15—H15A107.1
C3—C4—C19111.00 (13)C16—C15—H15A107.1
C3—C4—C18109.66 (15)C15—C16—H16A109.5
C19—C4—C18106.77 (14)C15—C16—H16B109.5
C3—C4—C5108.49 (13)H16A—C16—H16B109.5
C19—C4—C5109.94 (14)C15—C16—H16C109.5
C18—C4—C5110.99 (13)H16A—C16—H16C109.5
C4—C5—C6114.20 (12)H16B—C16—H16C109.5
C4—C5—C10114.19 (13)C15—C17—H17A109.5
C6—C5—C10103.40 (11)C15—C17—H17B109.5
C4—C5—H5A108.3H17A—C17—H17B109.5
C6—C5—H5A108.3C15—C17—H17C109.5
C10—C5—H5A108.3H17A—C17—H17C109.5
O2—C6—C7113.77 (12)H17B—C17—H17C109.5
O2—C6—C5113.85 (13)C4—C18—H18A109.5
C7—C6—C5103.57 (11)C4—C18—H18B109.5
O2—C6—H6A108.5H18A—C18—H18B109.5
C7—C6—H6A108.5C4—C18—H18C109.5
C5—C6—H6A108.5H18A—C18—H18C109.5
O1—C7—C8110.55 (12)H18B—C18—H18C109.5
O1—C7—C6101.05 (11)C4—C19—H19A109.5
C8—C7—C6111.48 (13)C4—C19—H19B109.5
O1—C7—H7A111.1H19A—C19—H19B109.5
C8—C7—H7A111.1C4—C19—H19C109.5
C6—C7—H7A111.1H19A—C19—H19C109.5
C14—C8—C9120.06 (15)H19B—C19—H19C109.5
C14—C8—C7122.22 (13)C9—C20—C10112.02 (12)
C9—C8—C7117.66 (13)C9—C20—H20A109.2
C11—C9—C8118.76 (14)C10—C20—H20A109.2
C11—C9—C20120.60 (14)C9—C20—H20B109.2
C8—C9—C20120.59 (14)C10—C20—H20B109.2
O1—C10—C1106.44 (13)H20A—C20—H20B107.9
C10—C1—C2—C319.7 (2)C2—C1—C10—C20−171.02 (14)
C1—C2—C3—C433.4 (2)C2—C1—C10—C5−42.0 (2)
C2—C3—C4—C1956.16 (18)C4—C5—C10—O1−106.69 (14)
C2—C3—C4—C18173.89 (13)C6—C5—C10—O117.99 (15)
C2—C3—C4—C5−64.74 (16)C4—C5—C10—C19.7 (2)
C3—C4—C5—C6−77.19 (16)C6—C5—C10—C1134.36 (14)
C19—C4—C5—C6161.26 (14)C4—C5—C10—C20138.16 (14)
C18—C4—C5—C643.4 (2)C6—C5—C10—C20−97.16 (14)
C3—C4—C5—C1041.52 (17)C8—C9—C11—O4178.72 (13)
C19—C4—C5—C10−80.04 (17)C20—C9—C11—O41.1 (2)
C18—C4—C5—C10162.07 (14)C8—C9—C11—C120.2 (2)
C4—C5—C6—O2−100.27 (16)C20—C9—C11—C12−177.48 (14)
C10—C5—C6—O2135.06 (13)C9—C11—C12—O3−179.81 (14)
C4—C5—C6—C7135.67 (14)O4—C11—C12—O31.6 (2)
C10—C5—C6—C711.00 (16)C9—C11—C12—C130.7 (2)
C10—O1—C7—C8−67.98 (14)O4—C11—C12—C13−177.83 (14)
C10—O1—C7—C650.16 (14)O3—C12—C13—C14179.36 (14)
O2—C6—C7—O1−160.80 (13)C11—C12—C13—C14−1.2 (2)
C5—C6—C7—O1−36.69 (15)O3—C12—C13—C15−1.0 (2)
O2—C6—C7—C8−43.34 (17)C11—C12—C13—C15178.49 (14)
C5—C6—C7—C880.77 (14)C9—C8—C14—C130.1 (2)
O1—C7—C8—C14−149.31 (14)C7—C8—C14—C13−176.94 (14)
C6—C7—C8—C1499.13 (16)C12—C13—C14—C80.8 (2)
O1—C7—C8—C933.56 (18)C15—C13—C14—C8−178.89 (15)
C6—C7—C8—C9−77.99 (16)C14—C13—C15—C17−101.80 (19)
C14—C8—C9—C11−0.6 (2)C12—C13—C15—C1778.55 (19)
C7—C8—C9—C11176.60 (13)C14—C13—C15—C1623.9 (2)
C14—C8—C9—C20177.05 (14)C12—C13—C15—C16−155.80 (15)
C7—C8—C9—C20−5.8 (2)C11—C9—C20—C10−169.78 (14)
C7—O1—C10—C1−166.58 (12)C8—C9—C20—C1012.6 (2)
C7—O1—C10—C2075.03 (13)O1—C10—C20—C9−46.44 (16)
C7—O1—C10—C5−43.17 (14)C1—C10—C20—C9−162.17 (13)
C2—C1—C10—O172.64 (16)C5—C10—C20—C966.15 (16)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
O3—H1O3···O2i0.85 (3)2.01 (3)2.8504 (17)169 (3)
O4—H1O4···O1ii0.84 (3)1.89 (3)2.7089 (16)165 (3)
C18—H18B···O3iii0.962.553.407 (2)149

Symmetry codes: (i) −x, y−1/2, −z+1/2; (ii) x−1, y, z; (iii) −x, y+1/2, −z+1/2.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: HB5689).

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