8-Hydro­xy-3,4-di­methyl­isocoumarin

The title compound, C₁₁H₁₀O₂, known as oospolactone, is a simple isocoumarin which has been isolated as a secondary metabolite from a culture extract of the fungi Gloeophyl­lum subferrugineum and G. sepiarium. The molecular core is planar, with an intramolecular hydrogen bond between the hydroxyl and ketone groups.

Key indicators

• Single-crystal X-ray study
• T = 81 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.060
• wR factor = 0.128
• Data-to-parameter ratio = 12.4

checkCIF/PLATON results

No syntax errors found



Alert level C
RINTA01_ALERT_3_C  The value of Rint is greater than 0.10
            Rint given   0.116
PLAT020_ALERT_3_C The value of Rint is greater than 0.10 .........       0.12
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT125_ALERT_4_C No _symmetry_space_group_name_Hall Given .......          ?

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

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

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Computing details

Data collection: SMART (Bruker 2001); cell refinement: SAINT-Plus (Bruker, 2001); data reduction: SAINT-Plus; program(s) used to solve structure: XS in SHELXTL (Sheldrick, 1998); program(s) used to refine structure: XL in SHELXTL; molecular graphics: XP in SHELXTL; software used to prepare material for publication: XCIF in SHELXTL.

8-hydroxy-3,4-dimethylisocoumarin

Crystal data

C11H10O3	Dx = 1.432 Mg m^−3
Mr = 190.19	Melting point: 129° K
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 11.283 (2) Å	Cell parameters from 356 reflections
b = 15.457 (3) Å	θ = 2.3–19.1°
c = 10.365 (2) Å	µ = 0.10 mm^−1
β = 102.56 (3)°	T = 81 K
V = 1764.3 (6) Å^3	Needle, colorless
Z = 8	0.15 × 0.10 × 0.06 mm
F(000) = 800

Data collection

Bruker–Siemens SMART APEX diffractometer	1650 independent reflections
Radiation source: normal-focus sealed tube	1057 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.116
Detector resolution: 8.3 pixels mm^-1	θmax = 25.5°, θmin = 2.3°
ω scans	h = −13→13
Absorption correction: multi-scan (SADABS; Sheldrick, 2001)	k = −18→18
Tmin = 0.985, Tmax = 0.994	l = −12→12
10791 measured reflections

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)] = 0.060	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.128	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	w = 1/[σ^2(Fo^2) + (0.0349P)^2 + 1.8671P] where P = (Fo^2 + 2Fc^2)/3
1650 reflections	(Δ/σ)max < 0.001
133 parameters	Δρmax = 0.23 e Å^−3
0 restraints	Δρmin = −0.22 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
C3	0.9093 (3)	0.3023 (2)	0.0853 (3)	0.0173 (7)
C4	0.9203 (3)	0.2207 (2)	0.0474 (3)	0.0169 (7)
C4A	0.8709 (3)	0.15051 (18)	0.1137 (3)	0.0152 (7)
C5	0.8783 (3)	0.06358 (19)	0.0798 (3)	0.0197 (7)
H5	0.9180	0.0478	0.0114	0.024*
C6	0.8278 (3)	0.0004 (2)	0.1458 (3)	0.0222 (8)
H6	0.8330	−0.0584	0.1212	0.027*
C7	0.7699 (3)	0.02065 (19)	0.2468 (3)	0.0202 (7)
H7	0.7354	−0.0238	0.2902	0.024*
C8	0.7626 (3)	0.10597 (18)	0.2838 (3)	0.0172 (7)
C8A	0.8132 (2)	0.17165 (19)	0.2177 (3)	0.0140 (7)
C1	0.8051 (3)	0.26053 (18)	0.2567 (3)	0.0145 (7)
C31	0.9535 (3)	0.38462 (19)	0.0372 (3)	0.0236 (8)
H31A	0.9918	0.3723	−0.0371	0.035*
H31B	1.0130	0.4116	0.1089	0.035*
H31C	0.8849	0.4240	0.0082	0.035*
C41	0.9829 (3)	0.1990 (2)	−0.0639 (3)	0.0233 (8)
H41A	1.0012	0.2525	−0.1063	0.035*
H41B	0.9294	0.1626	−0.1292	0.035*
H41C	1.0585	0.1678	−0.0282	0.035*
O2	0.85064 (17)	0.32194 (12)	0.18753 (18)	0.0168 (5)
O1	0.75960 (18)	0.28611 (13)	0.34692 (19)	0.0195 (5)
O8	0.70482 (19)	0.12384 (15)	0.3825 (2)	0.0219 (5)
H8	0.711 (3)	0.183 (3)	0.396 (4)	0.058 (13)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C3	0.0139 (16)	0.0251 (18)	0.0129 (16)	0.0017 (13)	0.0034 (13)	0.0043 (13)
C4	0.0150 (16)	0.0207 (17)	0.0143 (16)	0.0031 (13)	0.0017 (13)	0.0019 (14)
C4A	0.0119 (15)	0.0194 (16)	0.0119 (15)	0.0018 (13)	−0.0029 (12)	−0.0022 (13)
C5	0.0194 (17)	0.0209 (17)	0.0180 (17)	0.0056 (14)	0.0023 (13)	−0.0040 (14)
C6	0.0259 (18)	0.0157 (16)	0.0210 (18)	0.0031 (14)	−0.0037 (15)	−0.0043 (14)
C7	0.0215 (17)	0.0162 (17)	0.0205 (17)	−0.0012 (13)	−0.0003 (14)	0.0044 (14)
C8	0.0179 (16)	0.0177 (17)	0.0153 (16)	−0.0001 (13)	0.0021 (14)	−0.0026 (13)
C8A	0.0111 (15)	0.0173 (16)	0.0119 (15)	−0.0010 (13)	−0.0012 (12)	−0.0019 (13)
C1	0.0114 (15)	0.0178 (17)	0.0138 (16)	0.0009 (13)	0.0015 (13)	0.0029 (13)
C31	0.0225 (17)	0.0251 (18)	0.0221 (18)	0.0011 (14)	0.0024 (14)	0.0053 (14)
C41	0.0201 (17)	0.033 (2)	0.0178 (17)	0.0024 (15)	0.0065 (13)	−0.0011 (15)
O2	0.0182 (12)	0.0166 (12)	0.0166 (11)	−0.0003 (9)	0.0058 (9)	0.0016 (9)
O1	0.0225 (12)	0.0194 (12)	0.0182 (12)	0.0018 (9)	0.0079 (10)	−0.0021 (10)
O8	0.0275 (13)	0.0226 (13)	0.0180 (12)	−0.0029 (10)	0.0103 (10)	−0.0005 (10)

Geometric parameters (Å, º)

C3—C4	1.336 (4)	C8—O8	1.356 (3)
C3—O2	1.399 (3)	C8—C8A	1.413 (4)
C3—C31	1.491 (4)	C8A—C1	1.440 (4)
C4—C4A	1.458 (4)	C1—O1	1.226 (3)
C4—C41	1.516 (4)	C1—O2	1.356 (3)
C4A—C5	1.396 (4)	C31—H31A	0.9800
C4A—C8A	1.413 (4)	C31—H31B	0.9800
C5—C6	1.384 (4)	C31—H31C	0.9800
C5—H5	0.9500	C41—H41A	0.9800
C6—C7	1.384 (4)	C41—H41B	0.9800
C6—H6	0.9500	C41—H41C	0.9800
C7—C8	1.381 (4)	O8—H8	0.92 (4)
C7—H7	0.9500
C4—C3—O2	121.1 (3)	C8—C8A—C4A	120.4 (3)
C4—C3—C31	130.4 (3)	C8—C8A—C1	119.5 (2)
O2—C3—C31	108.5 (2)	C4A—C8A—C1	120.1 (3)
C3—C4—C4A	119.7 (2)	O1—C1—O2	116.6 (3)
C3—C4—C41	121.4 (3)	O1—C1—C8A	125.7 (3)
C4A—C4—C41	118.9 (3)	O2—C1—C8A	117.7 (2)
C5—C4A—C8A	118.5 (3)	C3—C31—H31A	109.5
C5—C4A—C4	123.2 (3)	C3—C31—H31B	109.5
C8A—C4A—C4	118.3 (2)	H31A—C31—H31B	109.5
C6—C5—C4A	120.1 (3)	C3—C31—H31C	109.5
C6—C5—H5	119.9	H31A—C31—H31C	109.5
C4A—C5—H5	119.9	H31B—C31—H31C	109.5
C5—C6—C7	121.8 (3)	C4—C41—H41A	109.5
C5—C6—H6	119.1	C4—C41—H41B	109.5
C7—C6—H6	119.1	H41A—C41—H41B	109.5
C8—C7—C6	119.5 (3)	C4—C41—H41C	109.5
C8—C7—H7	120.3	H41A—C41—H41C	109.5
C6—C7—H7	120.3	H41B—C41—H41C	109.5
O8—C8—C7	118.2 (3)	C1—O2—C3	123.0 (2)
O8—C8—C8A	122.1 (3)	C8—O8—H8	107 (2)
C7—C8—C8A	119.8 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O8—H8···O1	0.92 (4)	1.80 (4)	2.628 (3)	148 (3)