3-Hydr­oxy-3,6-dimethyl-2-(3-methyl­but-2-enyl­idene)-3,3a,7,7a-tetra­hydro­benzofuran-4(2H)-one

The title compound, C₁₅H₂₀O₃, was obtained from Angelica polymorpha and shows anti­feedant activity. The penta-1,3-diene fragment is essentially planar and the planarity extends to the adjacent C and O atoms of the benzofuran system. The six-membered ring of this system adopts a distorted chair conformation. The penta-1,3-diene fragment is essentially planar and the planarity extends to the adjacent C and O atoms of the benzofuran system. In the crystal structure, inter­molecular O—H...O hydrogen bonds form zigzag rows along b and weak C—H...O inter­actions further stabilize the structure.

Key indicators

• Single-crystal X-ray study
• T = 299 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.052
• wR factor = 0.117
• Data-to-parameter ratio = 9.7

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT220_ALERT_2_C Large Non-Solvent    C     Ueq(max)/Ueq(min) ...       2.95 Ratio
PLAT222_ALERT_3_C Large Non-Solvent    H     Ueq(max)/Ueq(min) ...       3.71 Ratio
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for        C13
PLAT340_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ...          5
PLAT480_ALERT_4_C Long H...A H-Bond Reported H10C   ..  O3      ..       2.69 Ang.

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           25.97
           From the CIF: _reflns_number_total               1648
           Count of symmetry unique reflns         1655
           Completeness (_total/calc)             99.58%
           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 C1     = .          R
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C6     = .          S
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C8     = .          S

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

   3 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   2 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
   2 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

Angelica polymorpha, belongs to parsley family, and is a species Chinese medicinal herb and has been widely used in folk medicine for the treatment of stomach ache, abdominal pain and rheumatism (Mi et al., 1995). It contains coumarin, terpenoids and volatile oils (Mi et al., 2003). Angelica polymorpha belongs to the same family as A. pubescens, A. silvesrtis and A. koreana. It was first obtained from Angelica polymorpha and shown to have strong antifeedant properties against insects (Mi et al., 1992). We present here the crystal structure of the title compound, (I), a constituent of Angelica polymorpha (Fig. 1).

Within the molecule of (I), the bond lengths and angles present no unusual features. The penta-1,3,diene fragment is essentially planar and the planarity extends to the adjacent C and O atoms of the benzofuran system. The maximum deviation from the meanplane through atoms O3, C9, C11, C12, C13, C14 is -0.036 (2)Å for atom C12. The six-membered ring, C1/C2/C3/C4/C5/C6, has a total puckering amplitude of 0.327 (1) %A (Cremer & Pople, 1975) and a distorted chair conformation [θ = 51.9 (4)° and φ= 3.3 (4)°]. In the crystal structure, intermolecular O2—H2···O1 hydrogen bonds form zigzag rows along b and weak C10—H10c···O3 interactions further stabilize the structure, Fig 2. Table 1.

Related literature

Angelica polymorpha is described by Mi et al. (2003) and the bioactivity of the title compound is described by Mi et al. (1992) and Mi (1995). For related literature, see: Cremer & Pople (1975).

S2. Experimental

The roots of Angelica polymorpha Maxim (1.0 kg) were extracted four times, each for 1.5 h, with refluxing ethyl acetate. After the removal of solvent under reduced pressure, the extract was obtained. Chromatography on silica gel eluting with petroleum ether - EtOAc (4:1 v/v) yielded 46 50 ml fractions. The title compound, (I), was obtained from fractions 11–15 and was recrystallized from methanol.

S3. Refinement

In the absence of significant anomalous scattering effects, 1164 Friedel pairs were merged. The OH proton H2 was located in a difference Fourier map and refined isotropically with U_eq = 1.5 U_eq(O). All other H-atoms were positioned geometrically and refined using a riding model with d(C—H) = 0.93 Å, U_iso=1.2U_eq (C) for aromatic 0.98 Å, U_iso = 1.2U_eq (C) for CH, 0.97 Å, U_iso = 1.2U_eq (C) for CH₂, 0.96 Å, U_iso = 1.5U_eq (C) for CH₃ atoms.

Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXTL (Sheldrick, 2001).

Figures

	Fig. 1. A View of the molecule of (I) showing the atom-labeling scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. The crystal packing, viewed along the X axis with hydrogen bonds drawn as dashed lines.

3-Hydroxy-3,6-dimethyl-2-(3-methylbut-2-enylidene)-3,3a,7,7a- tetrahydrobenzofuran-4(2H)-one

Crystal data

C15H20O3	F(000) = 536
Mr = 248.31	Dx = 1.147 Mg m^−3
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 1719 reflections
a = 6.9797 (11) Å	θ = 2.4–19.1°
b = 9.0174 (14) Å	µ = 0.08 mm^−1
c = 22.840 (4) Å	T = 299 K
V = 1437.5 (4) Å^3	Plate, colorless
Z = 4	0.20 × 0.20 × 0.06 mm

Data collection

Bruker SMART 4K CCD area-detector diffractometer	1251 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.063
Graphite monochromator	θmax = 26.0°, θmin = 1.8°
φ and ω scans	h = −8→8
12406 measured reflections	k = −10→11
1648 independent reflections	l = −27→27

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)] = 0.052	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.117	H atoms treated by a mixture of independent and constrained refinement
S = 1.07	w = 1/[σ^2(Fo^2) + (0.0518P)^2 + 0.1864P] where P = (Fo^2 + 2Fc^2)/3
1648 reflections	(Δ/σ)max < 0.001
170 parameters	Δρmax = 0.17 e Å^−3
0 restraints	Δρmin = −0.13 e Å^−3

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
C1	0.9568 (4)	0.6484 (4)	0.22512 (13)	0.0481 (8)
H1	1.0231	0.5594	0.2112	0.058*
C2	1.0072 (5)	0.7777 (4)	0.18612 (16)	0.0633 (9)
H2A	0.9919	0.8686	0.2084	0.076*
H2B	1.1412	0.7698	0.1754	0.076*
C3	0.8915 (6)	0.7897 (4)	0.13172 (15)	0.0621 (9)
C4	0.7185 (5)	0.7263 (4)	0.12712 (14)	0.0610 (9)
H4	0.6499	0.7400	0.0926	0.073*
C5	0.6334 (5)	0.6381 (3)	0.17280 (13)	0.0504 (8)
C6	0.7421 (4)	0.6173 (3)	0.22880 (12)	0.0410 (7)
H6	0.7243	0.5148	0.2419	0.049*
C7	0.9765 (7)	0.8828 (5)	0.08408 (19)	0.1009 (16)
H7A	0.8968	0.8774	0.0499	0.151*
H7B	1.1023	0.8469	0.0748	0.151*
H7C	0.9848	0.9839	0.0970	0.151*
C8	0.6780 (4)	0.7213 (4)	0.27827 (13)	0.0453 (8)
C9	0.8597 (4)	0.7356 (3)	0.31434 (13)	0.0426 (7)
C10	0.5086 (4)	0.6627 (5)	0.31343 (17)	0.0761 (12)
H10A	0.4841	0.7276	0.3459	0.114*
H10B	0.5377	0.5651	0.3277	0.114*
H10C	0.3973	0.6583	0.2888	0.114*
C11	0.8786 (5)	0.8000 (4)	0.36580 (13)	0.0513 (8)
H11	0.7680	0.8346	0.3839	0.062*
C12	1.0591 (5)	0.8210 (4)	0.39641 (14)	0.0592 (9)
H12	1.1666	0.7778	0.3794	0.071*
C13	1.0875 (6)	0.8944 (5)	0.44550 (16)	0.0733 (12)
C14	1.2835 (7)	0.9062 (6)	0.47239 (19)	0.115 (2)
H14A	1.3730	0.8494	0.4497	0.173*
H14B	1.2800	0.8686	0.5117	0.173*
H14C	1.3228	1.0082	0.4730	0.173*
C15	0.9326 (9)	0.9748 (6)	0.4781 (2)	0.121 (2)
H15A	0.8143	0.9670	0.4569	0.182*
H15B	0.9669	1.0774	0.4821	0.182*
H15C	0.9175	0.9316	0.5163	0.182*
O1	0.4750 (3)	0.5810 (3)	0.16660 (10)	0.0689 (7)
O2	0.6331 (4)	0.8598 (3)	0.25136 (10)	0.0624 (7)
H2	0.611 (7)	0.928 (5)	0.2772 (16)	0.094*
O3	1.0125 (3)	0.6779 (3)	0.28456 (9)	0.0586 (7)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0400 (16)	0.0488 (19)	0.0555 (18)	0.0054 (15)	0.0016 (14)	−0.0070 (15)
C2	0.0491 (18)	0.065 (2)	0.076 (2)	−0.0119 (19)	0.0105 (18)	−0.0034 (18)
C3	0.077 (2)	0.045 (2)	0.065 (2)	−0.0107 (19)	0.012 (2)	−0.0007 (16)
C4	0.076 (2)	0.055 (2)	0.0519 (18)	−0.008 (2)	−0.0079 (18)	0.0064 (17)
C5	0.0547 (19)	0.0372 (17)	0.0594 (19)	−0.0026 (17)	−0.0058 (17)	−0.0043 (15)
C6	0.0439 (16)	0.0312 (15)	0.0480 (16)	0.0012 (14)	−0.0015 (14)	0.0017 (13)
C7	0.112 (4)	0.097 (4)	0.093 (3)	−0.026 (3)	0.018 (3)	0.025 (3)
C8	0.0384 (16)	0.0442 (18)	0.0535 (17)	0.0015 (14)	−0.0019 (13)	−0.0022 (14)
C9	0.0379 (15)	0.0402 (17)	0.0495 (17)	0.0023 (15)	0.0020 (14)	0.0016 (14)
C10	0.0425 (18)	0.106 (3)	0.079 (2)	−0.012 (2)	0.0075 (19)	−0.024 (2)
C11	0.0470 (17)	0.055 (2)	0.0514 (17)	0.0028 (17)	0.0028 (15)	−0.0028 (16)
C12	0.061 (2)	0.063 (2)	0.0534 (19)	−0.0045 (19)	−0.0076 (16)	−0.0009 (17)
C13	0.099 (3)	0.068 (3)	0.053 (2)	−0.016 (2)	−0.014 (2)	0.0022 (19)
C14	0.140 (5)	0.119 (4)	0.088 (3)	−0.039 (4)	−0.059 (3)	0.005 (3)
C15	0.173 (6)	0.102 (4)	0.088 (3)	−0.003 (4)	0.006 (4)	−0.034 (3)
O1	0.0621 (16)	0.0666 (17)	0.0780 (16)	−0.0244 (14)	−0.0229 (13)	0.0106 (13)
O2	0.0681 (15)	0.0475 (14)	0.0717 (15)	0.0215 (12)	−0.0140 (13)	−0.0070 (12)
O3	0.0374 (11)	0.0802 (17)	0.0583 (13)	0.0118 (12)	−0.0056 (10)	−0.0134 (12)

Geometric parameters (Å, º)

C1—O3	1.437 (4)	C8—C10	1.524 (4)
C1—C2	1.509 (5)	C9—C11	1.318 (4)
C1—C6	1.527 (4)	C9—O3	1.368 (3)
C1—H1	0.9800	C10—H10A	0.9600
C2—C3	1.485 (5)	C10—H10B	0.9600
C2—H2A	0.9700	C10—H10C	0.9600
C2—H2B	0.9700	C11—C12	1.454 (4)
C3—C4	1.340 (5)	C11—H11	0.9300
C3—C7	1.497 (5)	C12—C13	1.317 (5)
C4—C5	1.441 (4)	C12—H12	0.9300
C4—H4	0.9300	C13—C15	1.500 (7)
C5—O1	1.228 (4)	C13—C14	1.503 (6)
C5—C6	1.499 (4)	C14—H14A	0.9600
C6—C8	1.535 (4)	C14—H14B	0.9600
C6—H6	0.9800	C14—H14C	0.9600
C7—H7A	0.9600	C15—H15A	0.9600
C7—H7B	0.9600	C15—H15B	0.9600
C7—H7C	0.9600	C15—H15C	0.9600
C8—O2	1.426 (4)	O2—H2	0.86 (4)
C8—C9	1.517 (4)
O3—C1—C2	110.6 (3)	O2—C8—C6	106.4 (2)
O3—C1—C6	104.4 (2)	C9—C8—C6	102.0 (2)
C2—C1—C6	113.8 (3)	C10—C8—C6	113.7 (3)
O3—C1—H1	109.3	C11—C9—O3	122.2 (3)
C2—C1—H1	109.3	C11—C9—C8	127.2 (3)
C6—C1—H1	109.3	O3—C9—C8	110.5 (2)
C3—C2—C1	115.0 (3)	C8—C10—H10A	109.5
C3—C2—H2A	108.5	C8—C10—H10B	109.5
C1—C2—H2A	108.5	H10A—C10—H10B	109.5
C3—C2—H2B	108.5	C8—C10—H10C	109.5
C1—C2—H2B	108.5	H10A—C10—H10C	109.5
H2A—C2—H2B	107.5	H10B—C10—H10C	109.5
C4—C3—C2	121.6 (3)	C9—C11—C12	125.0 (3)
C4—C3—C7	122.6 (4)	C9—C11—H11	117.5
C2—C3—C7	115.7 (3)	C12—C11—H11	117.5
C3—C4—C5	123.4 (3)	C13—C12—C11	127.3 (4)
C3—C4—H4	118.3	C13—C12—H12	116.4
C5—C4—H4	118.3	C11—C12—H12	116.4
O1—C5—C4	121.3 (3)	C12—C13—C15	123.9 (4)
O1—C5—C6	120.1 (3)	C12—C13—C14	121.4 (4)
C4—C5—C6	118.6 (3)	C15—C13—C14	114.7 (4)
C5—C6—C1	115.3 (3)	C13—C14—H14A	109.5
C5—C6—C8	113.8 (2)	C13—C14—H14B	109.5
C1—C6—C8	102.4 (2)	H14A—C14—H14B	109.5
C5—C6—H6	108.3	C13—C14—H14C	109.5
C1—C6—H6	108.3	H14A—C14—H14C	109.5
C8—C6—H6	108.3	H14B—C14—H14C	109.5
C3—C7—H7A	109.5	C13—C15—H15A	109.5
C3—C7—H7B	109.5	C13—C15—H15B	109.5
H7A—C7—H7B	109.5	H15A—C15—H15B	109.5
C3—C7—H7C	109.5	C13—C15—H15C	109.5
H7A—C7—H7C	109.5	H15A—C15—H15C	109.5
H7B—C7—H7C	109.5	H15B—C15—H15C	109.5
O2—C8—C9	110.1 (2)	C8—O2—H2	111 (3)
O2—C8—C10	111.1 (3)	C9—O3—C1	109.2 (2)
C9—C8—C10	113.0 (3)
O3—C1—C2—C3	−156.0 (3)	C1—C6—C8—C9	−27.2 (3)
C6—C1—C2—C3	−39.0 (4)	C5—C6—C8—C10	85.7 (3)
C1—C2—C3—C4	22.0 (5)	C1—C6—C8—C10	−149.2 (3)
C1—C2—C3—C7	−160.9 (3)	O2—C8—C9—C11	75.5 (4)
C2—C3—C4—C5	−2.3 (5)	C10—C8—C9—C11	−49.4 (5)
C7—C3—C4—C5	−179.1 (4)	C6—C8—C9—C11	−171.9 (3)
C3—C4—C5—O1	−179.4 (3)	O2—C8—C9—O3	−101.1 (3)
C3—C4—C5—C6	0.8 (5)	C10—C8—C9—O3	133.9 (3)
O1—C5—C6—C1	161.2 (3)	C6—C8—C9—O3	11.5 (3)
C4—C5—C6—C1	−19.1 (4)	O3—C9—C11—C12	1.5 (5)
O1—C5—C6—C8	−81.0 (4)	C8—C9—C11—C12	−174.8 (3)
C4—C5—C6—C8	98.8 (3)	C9—C11—C12—C13	174.3 (4)
O3—C1—C6—C5	158.4 (2)	C11—C12—C13—C15	−1.8 (6)
C2—C1—C6—C5	37.7 (4)	C11—C12—C13—C14	179.7 (4)
O3—C1—C6—C8	34.2 (3)	C11—C9—O3—C1	−166.2 (3)
C2—C1—C6—C8	−86.4 (3)	C8—C9—O3—C1	10.6 (3)
C5—C6—C8—O2	−36.9 (3)	C2—C1—O3—C9	94.3 (3)
C1—C6—C8—O2	88.2 (3)	C6—C1—O3—C9	−28.5 (3)
C5—C6—C8—C9	−152.2 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O1^i	0.86 (4)	1.98 (5)	2.839 (3)	173 (4)
C10—H10C···O3^ii	0.96	2.69	3.528 (4)	146

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