Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S160053681004208X/hb5689sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S160053681004208X/hb5689Isup2.hkl |
CCDC reference: 799662
Key indicators
- Single-crystal X-ray study
- T = 100 K
- Mean (C-C) = 0.002 Å
- R factor = 0.041
- wR factor = 0.107
- Data-to-parameter ratio = 15.2
checkCIF/PLATON results
No syntax errors found
Alert level C SHFSU01_ALERT_2_C Test not performed. _refine_ls_shift/su_max and _refine_ls_shift/esd_max not present. Absolute value of the parameter shift to su ratio given 0.001 PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) ..... 2 PLAT913_ALERT_3_C Missing # of Very Strong Reflections in FCF .... 1 PLAT912_ALERT_4_C Missing # of FCF Reflections Above STh/L= 0.600 33
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 32.39 From the CIF: _reflns_number_total 3534 Count of symmetry unique reflns 3568 Completeness (_total/calc) 99.05% 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 PLAT720_ALERT_4_G Number of Unusual/Non-Standard Labels .......... 3 PLAT791_ALERT_4_G Note: The Model has Chirality at C5 (Verify) S PLAT791_ALERT_4_G Note: The Model has Chirality at C6 (Verify) S PLAT791_ALERT_4_G Note: The Model has Chirality at C7 (Verify) S PLAT791_ALERT_4_G Note: The Model has Chirality at C10 (Verify) R
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 4 ALERT level C = Check and explain 6 ALERT level G = General alerts; check 0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 1 ALERT type 2 Indicator that the structure model may be wrong or deficient 2 ALERT type 3 Indicator that the structure quality may be low 7 ALERT type 4 Improvement, methodology, query or suggestion 0 ALERT type 5 Informative message, check
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).
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.
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, φ = 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 φ = 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 φ = 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.
For background to Verbenaceae, diterpenes and their biological activity, see: Hymavathi et al. (2009); Bunluepuech & Tewtrakul (2009); Esquivel et al. (1995). For ring conformations and ring puckering analysis, see: Cremer & Pople (1975). For bond-length data, see: Allen et al. (1987). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986).
Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).
C20H28O4 | F(000) = 720 |
Mr = 332.42 | Dx = 1.262 Mg m−3 |
Orthorhombic, P212121 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 6222 reflections |
a = 6.2767 (2) Å | θ = 2.4–32.3° |
b = 11.7358 (4) Å | µ = 0.09 mm−1 |
c = 23.7496 (7) Å | T = 100 K |
V = 1749.45 (10) Å3 | Block, colourless |
Z = 4 | 0.49 × 0.36 × 0.24 mm |
Bruker SMART APEXII CCD area-detector diffractometer | 3534 independent reflections |
Radiation source: sealed tube | 3079 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.037 |
φ and ω scans | θmax = 32.4°, θmin = 2.4° |
Absorption correction: multi-scan (SADABS; Bruker, 2005) | h = −8→9 |
Tmin = 0.959, Tmax = 0.979 | k = −17→16 |
15028 measured reflections | l = −34→35 |
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)] = 0.041 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.107 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.15 | w = 1/[σ2(Fo2) + (0.0548P)2 + 0.2019P] where P = (Fo2 + 2Fc2)/3 |
3534 reflections | (Δ/σ)max < 0.001 |
233 parameters | Δρmax = 0.36 e Å−3 |
0 restraints | Δρmin = −0.25 e Å−3 |
C20H28O4 | V = 1749.45 (10) Å3 |
Mr = 332.42 | Z = 4 |
Orthorhombic, P212121 | Mo Kα radiation |
a = 6.2767 (2) Å | µ = 0.09 mm−1 |
b = 11.7358 (4) Å | T = 100 K |
c = 23.7496 (7) Å | 0.49 × 0.36 × 0.24 mm |
Bruker SMART APEXII CCD area-detector diffractometer | 3534 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2005) | 3079 reflections with I > 2σ(I) |
Tmin = 0.959, Tmax = 0.979 | Rint = 0.037 |
15028 measured reflections |
R[F2 > 2σ(F2)] = 0.041 | 0 restraints |
wR(F2) = 0.107 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.15 | Δρmax = 0.36 e Å−3 |
3534 reflections | Δρmin = −0.25 e Å−3 |
233 parameters |
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 | 0.7000 (2) | 0.51248 (9) | 0.29871 (5) | 0.0162 (2) | |
O2 | 0.3927 (2) | 0.76867 (10) | 0.28241 (5) | 0.0179 (2) | |
H1O2 | 0.295 (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)* | |
C1 | 0.6494 (3) | 0.43356 (13) | 0.39056 (7) | 0.0193 (3) | |
H1A | 0.7202 | 0.3676 | 0.3746 | 0.023* | |
H1B | 0.5407 | 0.4058 | 0.4162 | 0.023* | |
C2 | 0.8142 (3) | 0.50212 (15) | 0.42483 (7) | 0.0231 (3) | |
H2A | 0.8018 | 0.4811 | 0.4642 | 0.028* | |
H2B | 0.9560 | 0.4811 | 0.4124 | 0.028* | |
C3 | 0.7889 (3) | 0.63252 (15) | 0.41961 (7) | 0.0200 (3) | |
H3A | 0.8483 | 0.6684 | 0.4529 | 0.024* | |
H3B | 0.8699 | 0.6588 | 0.3873 | 0.024* | |
C4 | 0.5563 (3) | 0.67027 (13) | 0.41290 (6) | 0.0162 (3) | |
C5 | 0.4707 (3) | 0.62326 (12) | 0.35629 (6) | 0.0141 (3) | |
H5A | 0.3147 | 0.6257 | 0.3574 | 0.017* | |
C6 | 0.5467 (3) | 0.69065 (12) | 0.30370 (6) | 0.0141 (3) | |
H6A | 0.6753 | 0.7334 | 0.3138 | 0.017* | |
C7 | 0.6093 (3) | 0.59624 (12) | 0.26148 (6) | 0.0146 (3) | |
H7A | 0.7152 | 0.6239 | 0.2344 | 0.018* | |
C8 | 0.4169 (3) | 0.54859 (12) | 0.23181 (6) | 0.0145 (3) | |
C9 | 0.2902 (3) | 0.47081 (12) | 0.26130 (6) | 0.0144 (3) | |
C10 | 0.5406 (3) | 0.49841 (12) | 0.34320 (6) | 0.0147 (3) | |
C11 | 0.1059 (3) | 0.43033 (12) | 0.23603 (6) | 0.0145 (3) | |
C12 | 0.0464 (3) | 0.46583 (13) | 0.18190 (6) | 0.0155 (3) | |
C13 | 0.1739 (3) | 0.54262 (13) | 0.15161 (6) | 0.0161 (3) | |
C14 | 0.3583 (3) | 0.58331 (12) | 0.17780 (6) | 0.0154 (3) | |
H14A | 0.4443 | 0.6350 | 0.1587 | 0.018* | |
C15 | 0.1063 (3) | 0.57665 (14) | 0.09244 (6) | 0.0196 (3) | |
H15A | 0.0468 | 0.5085 | 0.0745 | 0.023* | |
C16 | 0.2922 (3) | 0.61702 (16) | 0.05555 (7) | 0.0237 (4) | |
H16A | 0.2431 | 0.6281 | 0.0177 | 0.036* | |
H16B | 0.4030 | 0.5606 | 0.0559 | 0.036* | |
H16C | 0.3468 | 0.6876 | 0.0700 | 0.036* | |
C17 | −0.0714 (3) | 0.66608 (18) | 0.09427 (8) | 0.0286 (4) | |
H17A | −0.1905 | 0.6364 | 0.1150 | 0.043* | |
H17B | −0.1153 | 0.6841 | 0.0566 | 0.043* | |
H17C | −0.0197 | 0.7338 | 0.1124 | 0.043* | |
C18 | 0.5432 (3) | 0.80127 (14) | 0.41448 (7) | 0.0205 (3) | |
H18A | 0.5862 | 0.8280 | 0.4510 | 0.031* | |
H18B | 0.3994 | 0.8248 | 0.4072 | 0.031* | |
H18C | 0.6359 | 0.8326 | 0.3863 | 0.031* | |
C19 | 0.4188 (3) | 0.62608 (15) | 0.46181 (6) | 0.0213 (3) | |
H19A | 0.4798 | 0.6501 | 0.4969 | 0.032* | |
H19B | 0.4136 | 0.5444 | 0.4606 | 0.032* | |
H19C | 0.2771 | 0.6561 | 0.4585 | 0.032* | |
C20 | 0.3572 (3) | 0.42821 (12) | 0.31863 (6) | 0.0158 (3) | |
H20A | 0.4012 | 0.3492 | 0.3156 | 0.019* | |
H20B | 0.2363 | 0.4316 | 0.3440 | 0.019* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0152 (6) | 0.0138 (5) | 0.0197 (5) | 0.0030 (4) | 0.0026 (4) | 0.0022 (4) |
O2 | 0.0206 (6) | 0.0119 (5) | 0.0213 (5) | 0.0033 (5) | −0.0016 (5) | 0.0015 (4) |
O3 | 0.0204 (7) | 0.0206 (5) | 0.0226 (5) | −0.0081 (5) | −0.0026 (5) | 0.0026 (4) |
O4 | 0.0182 (6) | 0.0109 (5) | 0.0234 (5) | −0.0024 (4) | 0.0037 (5) | 0.0006 (4) |
C1 | 0.0231 (9) | 0.0138 (6) | 0.0211 (6) | 0.0039 (6) | −0.0016 (6) | 0.0029 (5) |
C2 | 0.0221 (9) | 0.0215 (8) | 0.0257 (7) | 0.0055 (7) | −0.0053 (7) | 0.0015 (6) |
C3 | 0.0194 (8) | 0.0193 (7) | 0.0214 (7) | −0.0001 (7) | −0.0029 (6) | −0.0001 (6) |
C4 | 0.0188 (8) | 0.0126 (6) | 0.0173 (6) | −0.0004 (6) | −0.0016 (6) | 0.0002 (5) |
C5 | 0.0145 (7) | 0.0107 (6) | 0.0171 (6) | 0.0005 (6) | 0.0002 (5) | 0.0004 (5) |
C6 | 0.0144 (7) | 0.0111 (6) | 0.0168 (6) | 0.0006 (6) | −0.0005 (5) | −0.0001 (5) |
C7 | 0.0153 (7) | 0.0120 (6) | 0.0165 (6) | 0.0000 (6) | 0.0008 (5) | 0.0015 (5) |
C8 | 0.0147 (8) | 0.0115 (6) | 0.0174 (6) | 0.0003 (5) | 0.0014 (5) | −0.0010 (5) |
C9 | 0.0162 (7) | 0.0102 (6) | 0.0168 (6) | 0.0009 (5) | 0.0023 (6) | −0.0011 (5) |
C10 | 0.0139 (7) | 0.0122 (6) | 0.0180 (6) | 0.0007 (6) | 0.0007 (5) | 0.0013 (5) |
C11 | 0.0161 (7) | 0.0086 (5) | 0.0189 (6) | −0.0002 (5) | 0.0037 (5) | −0.0002 (5) |
C12 | 0.0146 (8) | 0.0120 (6) | 0.0198 (6) | −0.0009 (6) | 0.0003 (6) | −0.0019 (5) |
C13 | 0.0184 (8) | 0.0130 (6) | 0.0168 (6) | 0.0008 (6) | 0.0011 (6) | −0.0012 (5) |
C14 | 0.0169 (8) | 0.0118 (6) | 0.0174 (6) | −0.0009 (6) | 0.0027 (5) | −0.0009 (5) |
C15 | 0.0236 (9) | 0.0180 (7) | 0.0171 (6) | −0.0057 (7) | −0.0017 (6) | 0.0002 (5) |
C16 | 0.0324 (10) | 0.0202 (7) | 0.0186 (6) | −0.0058 (8) | 0.0027 (7) | −0.0002 (6) |
C17 | 0.0235 (10) | 0.0304 (9) | 0.0318 (8) | 0.0020 (8) | −0.0039 (7) | 0.0089 (7) |
C18 | 0.0269 (9) | 0.0144 (6) | 0.0203 (6) | 0.0009 (7) | −0.0026 (7) | −0.0020 (5) |
C19 | 0.0262 (9) | 0.0206 (7) | 0.0171 (6) | 0.0005 (7) | 0.0028 (6) | 0.0013 (6) |
C20 | 0.0193 (8) | 0.0100 (6) | 0.0181 (6) | −0.0015 (6) | 0.0011 (6) | 0.0006 (5) |
O1—C7 | 1.4395 (18) | C8—C14 | 1.395 (2) |
O1—C10 | 1.4647 (19) | C8—C9 | 1.399 (2) |
O2—C6 | 1.4244 (19) | C9—C11 | 1.387 (2) |
O2—H1O2 | 0.84 (3) | C9—C20 | 1.510 (2) |
O3—C12 | 1.363 (2) | C10—C20 | 1.531 (2) |
O3—H1O3 | 0.85 (3) | C11—C12 | 1.402 (2) |
O4—C11 | 1.3882 (18) | C12—C13 | 1.404 (2) |
O4—H1O4 | 0.84 (3) | C13—C14 | 1.398 (2) |
C1—C10 | 1.520 (2) | C13—C15 | 1.521 (2) |
C1—C2 | 1.543 (3) | C14—H14A | 0.9300 |
C1—H1A | 0.9700 | C15—C17 | 1.532 (3) |
C1—H1B | 0.9700 | C15—C16 | 1.534 (2) |
C2—C3 | 1.544 (2) | C15—H15A | 0.9800 |
C2—H2A | 0.9700 | C16—H16A | 0.9600 |
C2—H2B | 0.9700 | C16—H16B | 0.9600 |
C3—C4 | 1.535 (3) | C16—H16C | 0.9600 |
C3—H3A | 0.9700 | C17—H17A | 0.9600 |
C3—H3B | 0.9700 | C17—H17B | 0.9600 |
C4—C19 | 1.537 (2) | C17—H17C | 0.9600 |
C4—C18 | 1.540 (2) | C18—H18A | 0.9600 |
C4—C5 | 1.549 (2) | C18—H18B | 0.9600 |
C5—C6 | 1.553 (2) | C18—H18C | 0.9600 |
C5—C10 | 1.561 (2) | C19—H19A | 0.9600 |
C5—H5A | 0.9800 | C19—H19B | 0.9600 |
C6—C7 | 1.545 (2) | C19—H19C | 0.9600 |
C6—H6A | 0.9800 | C20—H20A | 0.9700 |
C7—C8 | 1.506 (2) | C20—H20B | 0.9700 |
C7—H7A | 0.9800 | ||
C7—O1—C10 | 104.47 (12) | O1—C10—C20 | 107.42 (12) |
C6—O2—H1O2 | 107.5 (18) | C1—C10—C20 | 110.51 (12) |
C12—O3—H1O3 | 110.8 (18) | O1—C10—C5 | 103.28 (11) |
C11—O4—H1O4 | 103.5 (18) | C1—C10—C5 | 116.68 (12) |
C10—C1—C2 | 115.50 (13) | C20—C10—C5 | 111.72 (13) |
C10—C1—H1A | 108.4 | C9—C11—O4 | 119.91 (13) |
C2—C1—H1A | 108.4 | C9—C11—C12 | 121.15 (14) |
C10—C1—H1B | 108.4 | O4—C11—C12 | 118.93 (14) |
C2—C1—H1B | 108.4 | O3—C12—C11 | 121.38 (14) |
H1A—C1—H1B | 107.5 | O3—C12—C13 | 118.05 (13) |
C3—C2—C1 | 113.94 (14) | C11—C12—C13 | 120.57 (15) |
C3—C2—H2A | 108.8 | C14—C13—C12 | 117.61 (14) |
C1—C2—H2A | 108.8 | C14—C13—C15 | 123.51 (14) |
C3—C2—H2B | 108.8 | C12—C13—C15 | 118.88 (15) |
C1—C2—H2B | 108.8 | C8—C14—C13 | 121.84 (14) |
H2A—C2—H2B | 107.7 | C8—C14—H14A | 119.1 |
C4—C3—C2 | 113.11 (15) | C13—C14—H14A | 119.1 |
C4—C3—H3A | 109.0 | C13—C15—C17 | 110.89 (14) |
C2—C3—H3A | 109.0 | C13—C15—C16 | 113.37 (15) |
C4—C3—H3B | 109.0 | C17—C15—C16 | 111.00 (15) |
C2—C3—H3B | 109.0 | C13—C15—H15A | 107.1 |
H3A—C3—H3B | 107.8 | C17—C15—H15A | 107.1 |
C3—C4—C19 | 111.00 (13) | C16—C15—H15A | 107.1 |
C3—C4—C18 | 109.66 (15) | C15—C16—H16A | 109.5 |
C19—C4—C18 | 106.77 (14) | C15—C16—H16B | 109.5 |
C3—C4—C5 | 108.49 (13) | H16A—C16—H16B | 109.5 |
C19—C4—C5 | 109.94 (14) | C15—C16—H16C | 109.5 |
C18—C4—C5 | 110.99 (13) | H16A—C16—H16C | 109.5 |
C4—C5—C6 | 114.20 (12) | H16B—C16—H16C | 109.5 |
C4—C5—C10 | 114.19 (13) | C15—C17—H17A | 109.5 |
C6—C5—C10 | 103.40 (11) | C15—C17—H17B | 109.5 |
C4—C5—H5A | 108.3 | H17A—C17—H17B | 109.5 |
C6—C5—H5A | 108.3 | C15—C17—H17C | 109.5 |
C10—C5—H5A | 108.3 | H17A—C17—H17C | 109.5 |
O2—C6—C7 | 113.77 (12) | H17B—C17—H17C | 109.5 |
O2—C6—C5 | 113.85 (13) | C4—C18—H18A | 109.5 |
C7—C6—C5 | 103.57 (11) | C4—C18—H18B | 109.5 |
O2—C6—H6A | 108.5 | H18A—C18—H18B | 109.5 |
C7—C6—H6A | 108.5 | C4—C18—H18C | 109.5 |
C5—C6—H6A | 108.5 | H18A—C18—H18C | 109.5 |
O1—C7—C8 | 110.55 (12) | H18B—C18—H18C | 109.5 |
O1—C7—C6 | 101.05 (11) | C4—C19—H19A | 109.5 |
C8—C7—C6 | 111.48 (13) | C4—C19—H19B | 109.5 |
O1—C7—H7A | 111.1 | H19A—C19—H19B | 109.5 |
C8—C7—H7A | 111.1 | C4—C19—H19C | 109.5 |
C6—C7—H7A | 111.1 | H19A—C19—H19C | 109.5 |
C14—C8—C9 | 120.06 (15) | H19B—C19—H19C | 109.5 |
C14—C8—C7 | 122.22 (13) | C9—C20—C10 | 112.02 (12) |
C9—C8—C7 | 117.66 (13) | C9—C20—H20A | 109.2 |
C11—C9—C8 | 118.76 (14) | C10—C20—H20A | 109.2 |
C11—C9—C20 | 120.60 (14) | C9—C20—H20B | 109.2 |
C8—C9—C20 | 120.59 (14) | C10—C20—H20B | 109.2 |
O1—C10—C1 | 106.44 (13) | H20A—C20—H20B | 107.9 |
C10—C1—C2—C3 | 19.7 (2) | C2—C1—C10—C20 | −171.02 (14) |
C1—C2—C3—C4 | 33.4 (2) | C2—C1—C10—C5 | −42.0 (2) |
C2—C3—C4—C19 | 56.16 (18) | C4—C5—C10—O1 | −106.69 (14) |
C2—C3—C4—C18 | 173.89 (13) | C6—C5—C10—O1 | 17.99 (15) |
C2—C3—C4—C5 | −64.74 (16) | C4—C5—C10—C1 | 9.7 (2) |
C3—C4—C5—C6 | −77.19 (16) | C6—C5—C10—C1 | 134.36 (14) |
C19—C4—C5—C6 | 161.26 (14) | C4—C5—C10—C20 | 138.16 (14) |
C18—C4—C5—C6 | 43.4 (2) | C6—C5—C10—C20 | −97.16 (14) |
C3—C4—C5—C10 | 41.52 (17) | C8—C9—C11—O4 | 178.72 (13) |
C19—C4—C5—C10 | −80.04 (17) | C20—C9—C11—O4 | 1.1 (2) |
C18—C4—C5—C10 | 162.07 (14) | C8—C9—C11—C12 | 0.2 (2) |
C4—C5—C6—O2 | −100.27 (16) | C20—C9—C11—C12 | −177.48 (14) |
C10—C5—C6—O2 | 135.06 (13) | C9—C11—C12—O3 | −179.81 (14) |
C4—C5—C6—C7 | 135.67 (14) | O4—C11—C12—O3 | 1.6 (2) |
C10—C5—C6—C7 | 11.00 (16) | C9—C11—C12—C13 | 0.7 (2) |
C10—O1—C7—C8 | −67.98 (14) | O4—C11—C12—C13 | −177.83 (14) |
C10—O1—C7—C6 | 50.16 (14) | O3—C12—C13—C14 | 179.36 (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—C15 | 178.49 (14) |
C5—C6—C7—C8 | 80.77 (14) | C9—C8—C14—C13 | 0.1 (2) |
O1—C7—C8—C14 | −149.31 (14) | C7—C8—C14—C13 | −176.94 (14) |
C6—C7—C8—C14 | 99.13 (16) | C12—C13—C14—C8 | 0.8 (2) |
O1—C7—C8—C9 | 33.56 (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—C17 | 78.55 (19) |
C7—C8—C9—C11 | 176.60 (13) | C14—C13—C15—C16 | 23.9 (2) |
C14—C8—C9—C20 | 177.05 (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—C10 | 12.6 (2) |
C7—O1—C10—C20 | 75.03 (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—O1 | 72.64 (16) | C5—C10—C20—C9 | 66.15 (16) |
D—H···A | D—H | H···A | D···A | D—H···A |
O3—H1O3···O2i | 0.85 (3) | 2.01 (3) | 2.8504 (17) | 169 (3) |
O4—H1O4···O1ii | 0.84 (3) | 1.89 (3) | 2.7089 (16) | 165 (3) |
C18—H18B···O3iii | 0.96 | 2.55 | 3.407 (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. |
Experimental details
Crystal data | |
Chemical formula | C20H28O4 |
Mr | 332.42 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 100 |
a, b, c (Å) | 6.2767 (2), 11.7358 (4), 23.7496 (7) |
V (Å3) | 1749.45 (10) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.09 |
Crystal size (mm) | 0.49 × 0.36 × 0.24 |
Data collection | |
Diffractometer | Bruker SMART APEXII CCD area-detector |
Absorption correction | Multi-scan (SADABS; Bruker, 2005) |
Tmin, Tmax | 0.959, 0.979 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 15028, 3534, 3079 |
Rint | 0.037 |
(sin θ/λ)max (Å−1) | 0.754 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.041, 0.107, 1.15 |
No. of reflections | 3534 |
No. of parameters | 233 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.36, −0.25 |
Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).
D—H···A | D—H | H···A | D···A | D—H···A |
O3—H1O3···O2i | 0.85 (3) | 2.01 (3) | 2.8504 (17) | 169 (3) |
O4—H1O4···O1ii | 0.84 (3) | 1.89 (3) | 2.7089 (16) | 165 (3) |
C18—H18B···O3iii | 0.96 | 2.55 | 3.407 (2) | 148.8 |
Symmetry codes: (i) −x, y−1/2, −z+1/2; (ii) x−1, y, z; (iii) −x, y+1/2, −z+1/2. |
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, φ = 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 φ = 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 φ = 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.