(±)-1-Hydr­oxy-6,6-dimethyl-1H,6H-naphtho[1,2-c]furan-3,9-trione

The title compound, C₁₄H₁₂O₄, crystallizes as discrete mol­ecular species which form hydr­oxy-to-ketone hydrogen-bonded dimers disposed about crystallographic centres of symmetry.

Key indicators

• Single-crystal X-ray study
• T = 295 K
• Mean [sigma](C-C) = 0.004 Å
• Disorder in main residue
• R factor = 0.060
• wR factor = 0.179
• Data-to-parameter ratio = 12.9

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT432_ALERT_2_B Short Inter X...Y Contact  C4     ..  O2B     ..       2.89 Ang.
PLAT432_ALERT_2_B Short Inter X...Y Contact  C5     ..  O2B     ..       2.87 Ang.

Alert level C
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT094_ALERT_2_C Ratio of Maximum / Minimum Residual Density ....       2.61
PLAT161_ALERT_4_C Missing or Zero su (esd) on x-coordinate for ...        O2B
PLAT162_ALERT_4_C Missing or Zero su (esd) on y-coordinate for ...        O2B
PLAT163_ALERT_4_C Missing or Zero su (esd) on z-coordinate for ...        O2B
PLAT301_ALERT_3_C Main Residue  Disorder .........................       5.00 Perc.
PLAT432_ALERT_2_C Short Inter X...Y Contact  C3A    ..  O2B     ..       2.92 Ang.
PLAT432_ALERT_2_C Short Inter X...Y Contact  C5A    ..  O2B     ..       2.92 Ang.
PLAT432_ALERT_2_C Short Inter X...Y Contact  C9A    ..  O2B     ..       2.96 Ang.
PLAT432_ALERT_2_C Short Inter X...Y Contact  C9B    ..  O2B     ..       2.97 Ang.

   0 ALERT level A = In general: serious problem
   2 ALERT level B = Potentially serious problem
  10 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
   7 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

---

Computing details

Data collection: MSC/AFC7 Diffractometer Control Software (Molecular Structure Corporation, 1999); cell refinement: MSC/AFC7 Diffractometer Control Software; data reduction: TEXSAN for Windows (Molecular Structure Corporation, 2001); program(s) used to solve structure: TEXSAN for Windows; program(s) used to refine structure: TEXSAN for Windows and SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: TEXSAN for Windows and PLATON (Spek, 2003).

(±)1-Hydroxy-6,6-dimethyl-1H,6H-naphtho[1,2-c]furan-3,9-trione.

Crystal data

C14H12O4	F(000) = 512
Mr = 244.24	Dx = 1.361 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71069 Å
Hall symbol: -P 2ybc	Cell parameters from 25 reflections
a = 10.4825 (13) Å	θ = 12.7–17.4°
b = 7.0735 (17) Å	µ = 0.10 mm^−1
c = 16.081 (3) Å	T = 295 K
β = 90.556 (12)°	Plate, pale orange
V = 1192.3 (4) Å^3	0.45 × 0.40 × 0.15 mm
Z = 4

Data collection

Rigaku AFC-7R diffractometer	1441 reflections with I > 2σ(I)
Radiation source: Rigaku rotating anode	Rint = 0.018
Graphite monochromator	θmax = 25.0°, θmin = 2.5°
ω–2θ scans	h = −12→12
Absorption correction: ψ scan (North et al., 1968)	k = −8→0
Tmin = 0.956, Tmax = 0.985	l = −9→19
2395 measured reflections	3 standard reflections every 150 reflections
2100 independent reflections	intensity decay: 0.3%

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) = 0.179	H-atom parameters constrained
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0794P)^2 + 0.8739P] where P = (Fo^2 + 2Fc^2)/3
2100 reflections	(Δ/σ)max = 0.001
163 parameters	Δρmax = 0.60 e Å^−3
0 restraints	Δρmin = −0.23 e Å^−3

Special details

Experimental. The scan width was (1.79 + 0.30tanθ)° with an ω scan speed of 16° per minute (up to 4 scans to achieve I/σ(I) > 10). Stationary background counts were recorded at each end of the scan, and the scan time:background time ratio was 2:1.

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

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	Occ. (<1)
O1	1.2152 (2)	0.1483 (4)	0.58598 (15)	0.0704 (9)
O2A	1.0876 (3)	0.4032 (4)	0.60711 (16)	0.0721 (10)	0.900
O3	1.2926 (2)	−0.0951 (4)	0.65902 (18)	0.0864 (10)
O4	0.8437 (3)	0.3546 (4)	0.51498 (19)	0.0913 (11)
C1	1.0905 (3)	0.2349 (5)	0.5685 (2)	0.0554 (11)
C3	1.2027 (3)	−0.0102 (5)	0.6330 (2)	0.0575 (11)
C3A	1.0651 (2)	−0.0444 (4)	0.64348 (17)	0.0437 (9)
C4	1.0064 (3)	−0.1932 (4)	0.68471 (18)	0.0495 (9)
C5	0.8750 (3)	−0.1937 (4)	0.68604 (18)	0.0494 (9)
C5A	0.8020 (2)	−0.0531 (4)	0.64741 (16)	0.0405 (8)
C6	0.6576 (2)	−0.0641 (4)	0.65158 (17)	0.0474 (9)
C7	0.5936 (3)	0.0939 (5)	0.6053 (2)	0.0612 (11)
C8	0.6514 (3)	0.2297 (5)	0.5649 (2)	0.0613 (11)
C9	0.7895 (3)	0.2381 (4)	0.5592 (2)	0.0552 (11)
C9A	0.8639 (2)	0.0945 (4)	0.60540 (16)	0.0407 (8)
C9B	0.9976 (3)	0.0959 (4)	0.60519 (16)	0.0420 (9)
C10	0.6150 (3)	−0.0539 (6)	0.7429 (2)	0.0661 (13)
C11	0.6111 (3)	−0.2503 (5)	0.6125 (2)	0.0625 (11)
O2B	1.07060	0.25470	0.48650	0.0660*	0.100
H1A	1.07630	0.24910	0.51040	0.0660*	0.900
H2A	1.08830	0.50140	0.56670	0.0870*	0.900
H5	0.83290	−0.29350	0.71420	0.0590*
H7	0.50310	0.09640	0.60560	0.0730*
H4	1.05480	−0.29000	0.71100	0.0590*
H10A	0.52470	−0.06230	0.74530	0.0800*
H10B	0.65190	−0.15630	0.77300	0.0800*
H10C	0.64250	0.06210	0.76660	0.0800*
H11A	0.64010	−0.25820	0.55670	0.0750*
H11B	0.52040	−0.25370	0.61260	0.0750*
H11C	0.64370	−0.35370	0.64360	0.0750*
H8	0.60170	0.32480	0.53830	0.0740*
H1B	1.08340	0.35510	0.59470	0.0660*	0.100
H2B	1.07660	0.38450	0.47190	0.0790*	0.100

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0445 (12)	0.0836 (17)	0.0834 (17)	−0.0154 (11)	0.0111 (11)	0.0099 (14)
O2A	0.101 (2)	0.0544 (16)	0.0611 (15)	−0.0199 (14)	0.0114 (14)	−0.0006 (13)
O3	0.0400 (13)	0.106 (2)	0.113 (2)	0.0052 (13)	−0.0026 (13)	0.0151 (18)
O4	0.0855 (18)	0.0775 (18)	0.111 (2)	−0.0051 (14)	0.0037 (16)	0.0488 (17)
C1	0.0539 (18)	0.0559 (19)	0.0565 (19)	−0.0125 (15)	0.0080 (14)	−0.0020 (15)
C3	0.0424 (17)	0.072 (2)	0.0581 (19)	−0.0024 (16)	0.0044 (14)	−0.0017 (17)
C3A	0.0388 (14)	0.0516 (17)	0.0408 (15)	−0.0014 (12)	0.0043 (11)	−0.0049 (13)
C4	0.0445 (15)	0.0537 (18)	0.0502 (16)	0.0065 (13)	0.0028 (12)	0.0116 (14)
C5	0.0459 (15)	0.0500 (17)	0.0523 (17)	−0.0016 (13)	0.0088 (12)	0.0128 (14)
C5A	0.0376 (14)	0.0459 (16)	0.0380 (14)	−0.0011 (12)	0.0068 (11)	−0.0001 (12)
C6	0.0373 (15)	0.0563 (18)	0.0488 (16)	−0.0017 (13)	0.0066 (12)	0.0015 (14)
C7	0.0404 (16)	0.067 (2)	0.076 (2)	0.0052 (15)	−0.0015 (15)	0.0016 (18)
C8	0.0528 (18)	0.057 (2)	0.074 (2)	0.0118 (16)	−0.0097 (15)	0.0097 (17)
C9	0.0596 (19)	0.0491 (18)	0.0568 (18)	0.0011 (15)	0.0022 (14)	0.0098 (15)
C9A	0.0409 (14)	0.0404 (15)	0.0410 (14)	−0.0004 (11)	0.0049 (11)	0.0014 (12)
C9B	0.0429 (15)	0.0455 (16)	0.0376 (14)	−0.0044 (12)	0.0067 (11)	−0.0032 (12)
C10	0.0476 (17)	0.091 (3)	0.060 (2)	0.0019 (17)	0.0166 (14)	−0.0054 (18)
C11	0.0465 (17)	0.065 (2)	0.076 (2)	−0.0105 (15)	0.0066 (15)	−0.0071 (17)

Geometric parameters (Å, º)

O1—C1	1.468 (4)	C6—C10	1.541 (4)
O1—C3	1.359 (4)	C7—C8	1.311 (5)
O2A—C1	1.343 (4)	C8—C9	1.453 (4)
O2B—C1	1.3404	C9—C9A	1.477 (4)
O3—C3	1.190 (4)	C9A—C9B	1.402 (4)
O4—C9	1.231 (4)	C1—H1A	0.9500
O2A—H2A	0.9500	C1—H1B	0.9500
O2B—H2B	0.9500	C4—H4	0.9500
C1—C9B	1.508 (4)	C5—H5	0.9500
C3—C3A	1.474 (4)	C7—H7	0.9500
C3A—C9B	1.362 (4)	C8—H8	0.9500
C3A—C4	1.391 (4)	C10—H10B	0.9500
C4—C5	1.378 (4)	C10—H10C	0.9500
C5—C5A	1.397 (4)	C10—H10A	0.9500
C5A—C6	1.518 (3)	C11—H11B	0.9500
C5A—C9A	1.406 (4)	C11—H11C	0.9500
C6—C11	1.537 (4)	C11—H11A	0.9500
C6—C7	1.498 (4)
O2A···C9	3.417 (4)	C3A···H5^iii	3.0800
O2A···O4	2.963 (4)	C4···H2A^vii	3.0100
O2A···C4^i	3.233 (4)	C4···H2B^iv	2.9800
O2A···O4^ii	2.709 (4)	C5···H2B^iv	2.9200
O2A···C5^iii	3.415 (4)	C5···H11C	2.7600
O2B···C4^iv	2.8945	C5···H10B	2.7500
O2B···O4	2.5273	C9···H2A^ii	3.0300
O2B···C9A^iv	2.9625	C9···H2B^ii	3.0600
O2B···C9B^iv	2.9690	C10···H5	2.8800
O2B···C9	3.1828	C11···H5	2.8500
O2B···O4^ii	2.9061	H1A···O4	2.5500
O2B···C3A^iv	2.9236	H1B···O4	2.8100
O2B···C5^iv	2.8706	H1B···O4^ii	2.8200
O2B···C5A^iv	2.9172	H2A···O4	2.8800
O4···C1	2.847 (5)	H2A···C9^ii	3.0300
O4···C1^ii	3.275 (5)	H2A···C4^i	3.0100
O4···O2B^ii	2.9061	H2A···O4^ii	1.8100
O4···O2A	2.963 (4)	H2B···O4	2.5500
O4···O2B	2.5273	H2B···O4^ii	2.0400
O4···O2A^ii	2.709 (4)	H2B···C4^iv	2.9800
O1···H11A^iv	2.8700	H2B···C5^iv	2.9200
O2A···H4^i	2.7600	H2B···C9^ii	3.0600
O3···H10C^v	2.7900	H2B···H2B^ii	2.4700
O3···H11B^vi	2.7500	H4···O2A^vii	2.7600
O3···H7^vi	2.7300	H5···C11	2.8500
O3···H10A^vi	2.8000	H5···H10B	2.3400
O4···H1A	2.5500	H5···H11C	2.3200
O4···H2B	2.5500	H5···C3^v	2.9200
O4···H2A	2.8800	H5···C3A^v	3.0800
O4···H1B	2.8100	H5···C10	2.8800
O4···H2A^ii	1.8100	H7···O3^viii	2.7300
O4···H2B^ii	2.0400	H7···H11B	2.4900
O4···H1B^ii	2.8200	H7···H10A	2.5200
C1···O4	2.847 (5)	H10A···H11B	2.5300
C1···O4^ii	3.275 (5)	H10A···H7	2.5200
C3···C9^iv	3.488 (5)	H10A···O3^viii	2.8000
C3A···O2B^iv	2.9236	H10B···C5	2.7500
C4···O2A^vii	3.233 (4)	H10B···H5	2.3400
C4···O2B^iv	2.8945	H10B···H11C	2.5100
C5···O2B^iv	2.8706	H10C···O3^iii	2.7900
C5···O2A^v	3.415 (4)	H11A···O1^iv	2.8700
C5A···O2B^iv	2.9172	H11B···H7	2.4900
C9···O2B	3.1828	H11B···H10A	2.5300
C9···C3^iv	3.488 (5)	H11B···O3^viii	2.7500
C9···O2A	3.417 (4)	H11C···H10B	2.5100
C9A···O2B^iv	2.9625	H11C···C5	2.7600
C9B···O2B^iv	2.9690	H11C···H5	2.3200
C3···H5^iii	2.9200
C1—O1—C3	111.1 (2)	C5A—C9A—C9	120.6 (2)
C1—O2A—H2A	109.00	C9—C9A—C9B	121.1 (2)
C1—O2B—H2B	110.00	C1—C9B—C9A	130.9 (3)
O1—C1—C9B	103.3 (3)	C3A—C9B—C9A	120.6 (3)
O2A—C1—C9B	112.3 (3)	C1—C9B—C3A	108.5 (3)
O2B—C1—C9B	110.98	O1—C1—H1A	111.00
O1—C1—O2B	111.20	O2A—C1—H1A	111.00
O1—C1—O2A	107.8 (3)	C9B—C1—H1A	111.00
O1—C3—C3A	107.4 (3)	O1—C1—H1B	111.00
O1—C3—O3	122.1 (3)	O2B—C1—H1B	109.00
O3—C3—C3A	130.5 (3)	C9B—C1—H1B	111.00
C3—C3A—C9B	109.5 (3)	C3A—C4—H4	121.00
C4—C3A—C9B	122.5 (2)	C5—C4—H4	121.00
C3—C3A—C4	128.1 (3)	C5A—C5—H5	119.00
C3A—C4—C5	117.2 (3)	C4—C5—H5	119.00
C4—C5—C5A	122.3 (3)	C6—C7—H7	117.00
C5—C5A—C6	119.1 (2)	C8—C7—H7	117.00
C5—C5A—C9A	119.3 (2)	C9—C8—H8	119.00
C6—C5A—C9A	121.6 (2)	C7—C8—H8	119.00
C5A—C6—C10	109.8 (2)	C6—C10—H10A	110.00
C5A—C6—C7	112.5 (2)	C6—C10—H10B	109.00
C7—C6—C11	107.3 (2)	H10A—C10—H10B	109.00
C10—C6—C11	109.7 (3)	H10A—C10—H10C	110.00
C7—C6—C10	107.8 (2)	C6—C10—H10C	109.00
C5A—C6—C11	109.8 (2)	H10B—C10—H10C	109.00
C6—C7—C8	125.9 (3)	C6—C11—H11B	110.00
C7—C8—C9	121.8 (3)	C6—C11—H11C	110.00
O4—C9—C8	122.0 (3)	C6—C11—H11A	109.00
O4—C9—C9A	120.4 (3)	H11A—C11—H11C	110.00
C8—C9—C9A	117.5 (3)	H11B—C11—H11C	110.00
C5A—C9A—C9B	118.2 (2)	H11A—C11—H11B	109.00
C3—O1—C1—O2A	114.0 (3)	C5—C5A—C9A—C9	175.9 (3)
C3—O1—C1—C9B	−5.0 (3)	C5—C5A—C9A—C9B	−1.0 (4)
C1—O1—C3—O3	−174.8 (3)	C6—C5A—C9A—C9	−3.9 (4)
C1—O1—C3—C3A	4.4 (3)	C5—C5A—C6—C11	−59.1 (3)
O1—C1—C9B—C9A	−176.9 (3)	C9A—C5A—C6—C7	1.3 (4)
O2A—C1—C9B—C3A	−112.1 (3)	C9A—C5A—C6—C10	−118.8 (3)
O1—C1—C9B—C3A	3.7 (3)	C9A—C5A—C6—C11	120.7 (3)
O2A—C1—C9B—C9A	67.2 (4)	C6—C5A—C9A—C9B	179.3 (2)
O1—C3—C3A—C4	177.9 (3)	C11—C6—C7—C8	−120.9 (3)
O1—C3—C3A—C9B	−1.9 (3)	C5A—C6—C7—C8	−0.1 (4)
O3—C3—C3A—C9B	177.2 (4)	C10—C6—C7—C8	121.1 (4)
O3—C3—C3A—C4	−3.0 (6)	C6—C7—C8—C9	1.5 (5)
C3—C3A—C4—C5	179.9 (3)	C7—C8—C9—C9A	−4.0 (5)
C9B—C3A—C4—C5	−0.4 (4)	C7—C8—C9—O4	173.0 (3)
C4—C3A—C9B—C9A	−0.5 (4)	O4—C9—C9A—C5A	−171.9 (3)
C4—C3A—C9B—C1	178.9 (3)	O4—C9—C9A—C9B	4.9 (4)
C3—C3A—C9B—C1	−1.3 (3)	C8—C9—C9A—C5A	5.1 (4)
C3—C3A—C9B—C9A	179.2 (3)	C8—C9—C9A—C9B	−178.1 (3)
C3A—C4—C5—C5A	0.6 (4)	C5A—C9A—C9B—C3A	1.2 (4)
C4—C5—C5A—C9A	0.1 (4)	C9—C9A—C9B—C1	5.1 (5)
C4—C5—C5A—C6	179.9 (3)	C9—C9A—C9B—C3A	−175.7 (3)
C5—C5A—C6—C7	−178.5 (3)	C5A—C9A—C9B—C1	−178.1 (3)
C5—C5A—C6—C10	61.5 (3)

Symmetry codes: (i) x, y+1, z; (ii) −x+2, −y+1, −z+1; (iii) −x+2, y+1/2, −z+3/2; (iv) −x+2, −y, −z+1; (v) −x+2, y−1/2, −z+3/2; (vi) x+1, y, z; (vii) x, y−1, z; (viii) x−1, y, z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2A—H2A···O4^ii	0.95	1.81	2.709 (4)	156

Symmetry code: (ii) −x+2, −y+1, −z+1.