1,10-Dehydro­salviarin

The title diterpenoid, C₂₀H₂₀O₅, is a plant metabolite from Salvia wagneriana Polak. The mol­ecule is characterized by a penta­cyclic structure derived from a rearranged clerodane skeleton and shows, in addition to A and B rings, two olide systems forming C and D rings. Moreover, a β-substituted furan ring is present on the C ring. The crystal packing is mainly governed by normal van der Waals inter­actions. In the crystal structure, one non-classical hydrogen bond is also present, involving the carbonyl O atom of the γ-lactone ring and one activated C atom of a screw-related furan system. The structure exhibits a remarkable isomorphism with that of the previously characterized salviarin. The anti­feedant activity of dehydro­salviarin against the insect Spodoptera littoralis, a destructive pest for tropical and subtropical agriculture, is also reported.

Key indicators

• Single-crystal X-ray study
• T = 291 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.035
• wR factor = 0.073
• Data-to-parameter ratio = 9.5

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT230_ALERT_2_B Hirshfeld Test Diff for    O1     -   C15     ..      14.15 su

Alert level C
STRVA01_ALERT_4_C           Flack parameter is too small
           From the CIF: _refine_ls_abs_structure_Flack   -1.400
           From the CIF: _refine_ls_abs_structure_Flack_su    1.200

Author Response: without merging of Friedel Pairs 3721 independent reflections 2443 reflections with I > 2\s(I) Flack parameter 0.2(9)

PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low .......       0.98
PLAT032_ALERT_4_C Std. Uncertainty in Flack Parameter too High ...       1.20
PLAT033_ALERT_2_C Flack Parameter Value Deviates from Zero .......      -1.40
PLAT241_ALERT_2_C Check High      Ueq as Compared to Neighbors for         O1

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           27.55
           From the CIF: _reflns_number_total               2149
           Count of symmetry unique reflns         2193
           Completeness (_total/calc)             97.99%
           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

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

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   3 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
   3 ALERT type 4 Improvement, methodology, query or suggestion


checkCIF publication errors

Alert level A
PUBL024_ALERT_1_A The number of authors is greater than 5.
              Please specify the role of each of the co-authors
              for your paper.

Author Response: The authors Mattia and Puliti performed the crystallographic work, the other authors the biological essay and the purification of the substance. I used the Federico II facilities because I worked at Department of Chemistry of University Federico II for many years before to move to University of Salerno.

   1 ALERT level A = Data missing that is essential or data in wrong format
   0 ALERT level G = General alerts. Data that may be required is missing

---

Computing details

Data collection: COLLECT (Hooft, 1999); cell refinement: DIRAX (Duisenberg, 1992); data reduction: COLLECT; program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97.

(I)

Crystal data

C20H20O5	F(000) = 720
Mr = 340.36	Dx = 1.367 Mg m^−3
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 5071 reflections
a = 8.014 (7) Å	θ = 4.6–20.6°
b = 11.970 (12) Å	µ = 0.10 mm^−1
c = 17.239 (18) Å	T = 291 K
V = 1654 (3) Å^3	Elongated prism, colourless
Z = 4	0.55 × 0.20 × 0.15 mm

Data collection

Nonius KappaCCD diffractometer	2149 independent reflections
Radiation source: fine-focus sealed tube	1517 reflections with I > 2σ(I)
Horizonally mounted graphite crystal monochromator	Rint = 0.036
Detector resolution: 9 pixels mm^-1	θmax = 27.6°, θmin = 4.2°
φ and ω scans	h = −9→10
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	k = −15→15
Tmin = 0.903, Tmax = 0.986	l = −17→22
12254 measured reflections

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)] = 0.035	H-atom parameters constrained
wR(F^2) = 0.073	w = 1/[σ^2(Fo^2) + (0.0402P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.00	(Δ/σ)max < 0.001
2149 reflections	Δρmax = 0.13 e Å^−3
227 parameters	Δρmin = −0.17 e Å^−3
0 restraints	Absolute structure: Flack test results are meaningless (Flack, 1983), therefore the absolute configuration was chosen according to that of the known clerodin bromalactone (Rogers et al., 1979)
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.

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	0.7320 (2)	−0.18230 (15)	0.03003 (10)	0.0705 (5)
O2	0.32932 (16)	0.04806 (13)	0.04546 (8)	0.0499 (4)
O3	0.1288 (2)	0.13798 (17)	−0.01019 (9)	0.0720 (6)
O4	−0.10727 (19)	0.32518 (16)	0.31839 (9)	0.0619 (5)
O5	−0.31045 (19)	0.2019 (2)	0.34119 (10)	0.0821 (6)
C1	0.3049 (2)	0.10315 (17)	0.28599 (11)	0.0407 (5)
H1	0.4140	0.0771	0.2825	0.049*
C2	0.2034 (3)	0.06780 (18)	0.35165 (12)	0.0480 (6)
H2	0.2545	0.0326	0.3935	0.058*
C3	0.0412 (3)	0.08444 (17)	0.35320 (11)	0.0462 (5)
H3	−0.0204	0.0607	0.3958	0.055*
C4	−0.0454 (2)	0.14131 (18)	0.28691 (11)	0.0419 (5)
H4	−0.1002	0.0857	0.2539	0.050*
C5	0.0700 (2)	0.21543 (17)	0.23790 (10)	0.0330 (4)
C6	−0.0105 (2)	0.23556 (19)	0.15862 (11)	0.0436 (5)
H6A	−0.0364	0.1641	0.1350	0.052*
H6B	−0.1146	0.2756	0.1658	0.052*
C7	0.1004 (3)	0.3016 (2)	0.10419 (12)	0.0499 (6)
H7A	0.1239	0.3743	0.1264	0.060*
H7B	0.0436	0.3127	0.0551	0.060*
C8	0.2633 (2)	0.23877 (17)	0.09067 (10)	0.0393 (5)
H8	0.3336	0.2891	0.0600	0.047*
C9	0.3603 (2)	0.21722 (17)	0.16674 (10)	0.0342 (5)
C10	0.2482 (2)	0.17103 (15)	0.23086 (10)	0.0305 (4)
C11	0.5047 (2)	0.13865 (16)	0.14495 (10)	0.0354 (4)
H11A	0.5775	0.1768	0.1086	0.042*
H11B	0.5693	0.1225	0.1912	0.042*
C12	0.4485 (2)	0.03008 (17)	0.10936 (10)	0.0369 (5)
H12	0.3936	−0.0147	0.1496	0.044*
C13	0.5870 (2)	−0.03732 (18)	0.07514 (10)	0.0368 (5)
C14	0.7403 (2)	0.0000 (2)	0.04275 (12)	0.0459 (5)
H14	0.7770	0.0736	0.0402	0.055*
C15	0.8213 (3)	−0.0888 (2)	0.01696 (13)	0.0517 (6)
H15	0.9254	−0.0870	−0.0069	0.062*
C16	0.5882 (3)	−0.1486 (2)	0.06604 (13)	0.0558 (6)
H16	0.5032	−0.1962	0.0820	0.067*
C17	0.2335 (2)	0.13799 (19)	0.04029 (11)	0.0442 (5)
C18	−0.1714 (3)	0.2216 (2)	0.31806 (12)	0.0535 (6)
C19	0.0609 (3)	0.32227 (19)	0.28700 (12)	0.0483 (5)
H19A	0.1426	0.3201	0.3285	0.058*
H19B	0.0819	0.3876	0.2552	0.058*
C20	0.4380 (3)	0.32800 (18)	0.19522 (12)	0.0490 (5)
H20A	0.3508	0.3792	0.2091	0.059*
H20B	0.5047	0.3598	0.1546	0.059*
H20C	0.5069	0.3138	0.2397	0.059*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0840 (12)	0.0615 (12)	0.0659 (11)	0.0237 (10)	0.0155 (9)	−0.0036 (9)
O2	0.0460 (8)	0.0567 (10)	0.0471 (8)	0.0084 (7)	−0.0179 (6)	−0.0101 (8)
O3	0.0669 (10)	0.1036 (15)	0.0455 (10)	0.0305 (10)	−0.0253 (8)	−0.0176 (9)
O4	0.0651 (10)	0.0625 (12)	0.0581 (10)	0.0229 (9)	0.0101 (8)	−0.0129 (9)
O5	0.0434 (9)	0.1393 (19)	0.0636 (11)	0.0137 (10)	0.0157 (8)	0.0061 (12)
C1	0.0411 (10)	0.0435 (13)	0.0374 (11)	0.0062 (9)	0.0015 (8)	0.0062 (10)
C2	0.0644 (14)	0.0418 (15)	0.0378 (12)	0.0111 (11)	0.0034 (9)	0.0104 (10)
C3	0.0619 (14)	0.0365 (13)	0.0401 (12)	−0.0027 (11)	0.0129 (10)	0.0054 (10)
C4	0.0401 (11)	0.0462 (13)	0.0393 (11)	−0.0073 (9)	0.0035 (8)	−0.0058 (10)
C5	0.0358 (10)	0.0321 (11)	0.0311 (9)	0.0008 (8)	−0.0006 (7)	−0.0021 (9)
C6	0.0365 (10)	0.0547 (15)	0.0397 (11)	0.0114 (9)	−0.0028 (8)	−0.0016 (10)
C7	0.0576 (12)	0.0534 (15)	0.0386 (11)	0.0179 (11)	−0.0041 (9)	0.0090 (11)
C8	0.0438 (10)	0.0432 (13)	0.0309 (10)	0.0024 (9)	0.0014 (8)	0.0099 (9)
C9	0.0352 (10)	0.0338 (12)	0.0336 (10)	−0.0005 (8)	−0.0005 (7)	0.0038 (9)
C10	0.0341 (9)	0.0282 (10)	0.0293 (9)	−0.0022 (8)	−0.0023 (7)	−0.0021 (8)
C11	0.0330 (10)	0.0426 (12)	0.0305 (10)	−0.0021 (8)	−0.0004 (7)	0.0018 (9)
C12	0.0366 (10)	0.0444 (13)	0.0298 (10)	−0.0013 (9)	−0.0035 (7)	0.0053 (9)
C13	0.0398 (11)	0.0417 (14)	0.0289 (10)	0.0047 (9)	−0.0013 (8)	0.0045 (9)
C14	0.0453 (11)	0.0510 (14)	0.0415 (12)	0.0024 (10)	0.0012 (9)	0.0042 (10)
C15	0.0457 (12)	0.0624 (17)	0.0470 (13)	0.0082 (12)	0.0110 (9)	0.0032 (12)
C16	0.0621 (15)	0.0480 (17)	0.0574 (15)	0.0044 (12)	0.0132 (11)	0.0015 (12)
C17	0.0389 (11)	0.0623 (15)	0.0315 (10)	0.0072 (10)	−0.0019 (9)	0.0027 (10)
C18	0.0442 (13)	0.077 (2)	0.0390 (13)	0.0091 (12)	0.0011 (9)	−0.0036 (13)
C19	0.0550 (13)	0.0374 (13)	0.0526 (13)	0.0030 (10)	0.0033 (10)	−0.0047 (11)
C20	0.0515 (12)	0.0443 (14)	0.0512 (12)	−0.0087 (11)	0.0069 (10)	−0.0029 (11)

Geometric parameters (Å, º)

O1—C15	1.348 (3)	C7—H7A	0.9700
O1—C16	1.369 (3)	C7—H7B	0.9700
O2—C12	1.474 (2)	C8—C17	1.506 (3)
O2—C17	1.325 (3)	C8—C9	1.546 (3)
O3—C17	1.209 (2)	C8—H8	0.9800
O4—C18	1.343 (3)	C9—C10	1.528 (3)
O4—C19	1.453 (3)	C9—C11	1.538 (3)
O5—C18	1.207 (3)	C9—C20	1.545 (3)
C1—C2	1.457 (3)	C11—C12	1.506 (3)
C1—C10	1.330 (3)	C11—H11A	0.9700
C1—H1	0.9300	C11—H11B	0.9700
C2—C3	1.315 (3)	C12—C13	1.494 (3)
C2—H2	0.9300	C12—H12	0.9800
C3—C4	1.500 (3)	C13—C14	1.421 (3)
C3—H3	0.9300	C13—C16	1.341 (3)
C4—C18	1.493 (3)	C14—C15	1.323 (3)
C4—C5	1.535 (3)	C14—H14	0.9300
C4—H4	0.9800	C15—H15	0.9300
C5—C10	1.529 (3)	C16—H16	0.9300
C5—C6	1.531 (3)	C19—H19A	0.9700
C5—C19	1.535 (3)	C19—H19B	0.9700
C6—C7	1.515 (3)	C20—H20A	0.9600
C6—H6A	0.9700	C20—H20B	0.9600
C6—H6B	0.9700	C20—H20C	0.9600
C7—C8	1.525 (3)
C15—O1—C16	106.13 (18)	C8—C9—C20	109.21 (17)
C12—O2—C17	122.98 (15)	C1—C10—C5	118.33 (16)
C18—O4—C19	109.34 (17)	C1—C10—C9	122.50 (17)
C2—C1—C10	122.81 (18)	C5—C10—C9	118.74 (16)
C10—C1—H1	118.6	C12—C11—C9	113.70 (15)
C2—C1—H1	118.6	C12—C11—H11A	108.8
C1—C2—C3	121.58 (19)	C9—C11—H11A	108.8
C3—C2—H2	119.2	C12—C11—H11B	108.8
C1—C2—H2	119.2	C9—C11—H11B	108.8
C2—C3—C4	120.69 (18)	H11A—C11—H11B	107.7
C2—C3—H3	119.7	O2—C12—C13	105.37 (15)
C4—C3—H3	119.7	O2—C12—C11	111.86 (16)
C18—C4—C3	109.31 (17)	C13—C12—C11	113.88 (16)
C18—C4—C5	103.50 (19)	O2—C12—H12	108.5
C3—C4—C5	113.75 (16)	C13—C12—H12	108.5
C18—C4—H4	110.0	C11—C12—H12	108.5
C3—C4—H4	110.0	C14—C13—C16	105.08 (19)
C5—C4—H4	110.0	C16—C13—C12	126.02 (19)
C10—C5—C6	112.19 (15)	C14—C13—C12	128.9 (2)
C10—C5—C19	112.21 (15)	C13—C14—C15	107.7 (2)
C6—C5—C19	109.94 (17)	C15—C14—H14	126.2
C10—C5—C4	113.93 (16)	C13—C14—H14	126.2
C6—C5—C4	109.17 (16)	C14—C15—O1	110.52 (19)
C19—C5—C4	98.59 (16)	C14—C15—H15	124.7
C7—C6—C5	112.82 (17)	O1—C15—H15	124.7
C7—C6—H6A	109.0	O1—C16—C13	110.6 (2)
C5—C6—H6A	109.0	C13—C16—H16	124.7
C7—C6—H6B	109.0	O1—C16—H16	124.7
C5—C6—H6B	109.0	O2—C17—O3	116.77 (19)
H6A—C6—H6B	107.8	O3—C17—C8	121.71 (19)
C6—C7—C8	109.89 (18)	O2—C17—C8	121.33 (16)
C6—C7—H7A	109.7	O4—C18—O5	122.1 (2)
C8—C7—H7A	109.7	O5—C18—C4	128.2 (3)
C6—C7—H7B	109.7	O4—C18—C4	109.70 (18)
C8—C7—H7B	109.7	O4—C19—C5	105.64 (17)
H7A—C7—H7B	108.2	O4—C19—H19A	110.6
C17—C8—C7	110.31 (17)	C5—C19—H19A	110.6
C17—C8—C9	115.82 (17)	O4—C19—H19B	110.6
C7—C8—C9	112.52 (16)	C5—C19—H19B	110.6
C17—C8—H8	105.8	H19A—C19—H19B	108.7
C7—C8—H8	105.8	C9—C20—H20A	109.5
C9—C8—H8	105.8	C9—C20—H20B	109.5
C10—C9—C11	113.44 (16)	H20A—C20—H20B	109.5
C10—C9—C8	112.26 (16)	C9—C20—H20C	109.5
C11—C9—C8	105.84 (15)	H20A—C20—H20C	109.5
C10—C9—C20	108.53 (16)	H20B—C20—H20C	109.5
C11—C9—C20	107.38 (16)
C10—C1—C2—C3	12.4 (3)	C20—C9—C10—C5	83.1 (2)
C1—C2—C3—C4	−0.2 (3)	C10—C9—C11—C12	65.1 (2)
C2—C3—C4—C18	−138.1 (2)	C8—C9—C11—C12	−58.39 (19)
C2—C3—C4—C5	−23.0 (3)	C20—C9—C11—C12	−174.96 (15)
C18—C4—C5—C10	152.61 (15)	C17—O2—C12—C13	−149.71 (17)
C3—C4—C5—C10	34.1 (2)	C17—O2—C12—C11	−25.5 (2)
C18—C4—C5—C6	−81.1 (2)	C9—C11—C12—O2	50.2 (2)
C3—C4—C5—C6	160.39 (17)	C9—C11—C12—C13	169.53 (15)
C18—C4—C5—C19	33.58 (18)	O2—C12—C13—C14	94.1 (2)
C3—C4—C5—C19	−84.93 (19)	O2—C12—C13—C16	−83.1 (2)
C10—C5—C6—C7	−48.8 (2)	C11—C12—C13—C16	153.9 (2)
C19—C5—C6—C7	76.8 (2)	C11—C12—C13—C14	−28.8 (3)
C4—C5—C6—C7	−176.04 (16)	C16—C13—C14—C15	0.0 (2)
C5—C6—C7—C8	59.9 (2)	C12—C13—C14—C15	−177.64 (18)
C6—C7—C8—C17	72.0 (2)	C13—C14—C15—O1	0.0 (2)
C6—C7—C8—C9	−59.0 (2)	C16—O1—C15—C14	−0.1 (2)
C7—C8—C9—C11	171.48 (16)	C14—C13—C16—O1	−0.1 (2)
C17—C8—C9—C10	−81.0 (2)	C12—C13—C16—O1	177.65 (16)
C7—C8—C9—C10	47.2 (2)	C15—O1—C16—C13	0.2 (2)
C17—C8—C9—C11	43.3 (2)	C12—O2—C17—O3	−172.61 (18)
C17—C8—C9—C20	158.64 (16)	C12—O2—C17—C8	12.3 (3)
C7—C8—C9—C20	−73.2 (2)	C7—C8—C17—O3	33.3 (3)
C2—C1—C10—C5	1.3 (3)	C9—C8—C17—O3	162.56 (19)
C2—C1—C10—C9	173.61 (19)	C7—C8—C17—O2	−151.79 (18)
C6—C5—C10—C1	−149.03 (19)	C9—C8—C17—O2	−22.5 (3)
C19—C5—C10—C1	86.6 (2)	C19—O4—C18—O5	−179.8 (2)
C4—C5—C10—C1	−24.3 (2)	C19—O4—C18—C4	1.0 (2)
C6—C5—C10—C9	38.3 (2)	C3—C4—C18—O5	−80.9 (3)
C19—C5—C10—C9	−86.0 (2)	C5—C4—C18—O5	157.6 (2)
C4—C5—C10—C9	163.02 (16)	C3—C4—C18—O4	98.2 (2)
C11—C9—C10—C1	30.1 (2)	C5—C4—C18—O4	−23.3 (2)
C8—C9—C10—C1	150.00 (19)	C18—O4—C19—C5	21.9 (2)
C20—C9—C10—C1	−89.2 (2)	C10—C5—C19—O4	−154.21 (16)
C11—C9—C10—C5	−157.63 (15)	C6—C5—C19—O4	80.19 (19)
C8—C9—C10—C5	−37.7 (2)	C4—C5—C19—O4	−33.89 (19)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C16—H16···O5^i	0.93	2.37	3.273 (4)	163

Symmetry code: (i) −x, y−1/2, −z+1/2.