Dimethyl 3t,4t-dicarboxy­tetra­hydro­furan-2r,5c-dicarboxyl­ate

Esterification of tetra­hydro­furan-2r,3t,4t,5c-tetra­carboxylic acid gave selectively the title compound, C₁₀H₁₂O₉, in which the two more acidic carboxylic acid groups, in positions 2 and 5, have been esterified. The five-membered ring is in a twist conformation. Hydrogen bonding results in double chains, or ribbons, running along the c axis.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.039
• wR factor = 0.100
• Data-to-parameter ratio = 12.1

checkCIF/PLATON results

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Alert level C
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low .......       0.98

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

   0 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
   1 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: KappaCCD Server Software (Nonius, 1997); cell refinement: HKL-2000 (Otwinowski & Minor, 1997); data reduction: HKL-2000; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1999); software used to prepare material for publication: SHELXTL.

Dimethyl 3 t,4 t-dicarboxytetrahydrofuran-2r,5c-dicarboxylate

Crystal data

C10H12O9	F(000) = 576
Mr = 276.20	Dx = 1.608 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 7691 reflections
a = 5.5117 (4) Å	θ = 3.0–25.7°
b = 25.419 (3) Å	µ = 0.15 mm^−1
c = 8.1970 (7) Å	T = 100 K
β = 96.634 (6)°	Platelet, colourless
V = 1140.73 (19) Å^3	0.26 × 0.22 × 0.17 mm
Z = 4

Data collection

Nonius KappaCCD diffractometer	1700 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.033
Graphite monochromator	θmax = 25.7°, θmin = 3.0°
φ scans	h = 0→6
7691 measured reflections	k = 0→30
2112 independent reflections	l = −9→9

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)] = 0.039	H-atom parameters constrained
wR(F^2) = 0.100	w = 1/[σ^2(Fo^2) + (0.0165P)^2 + 0.7399P] where P = (Fo^2 + 2Fc^2)/3
S = 1.04	(Δ/σ)max < 0.001
2112 reflections	Δρmax = 0.19 e Å^−3
175 parameters	Δρmin = −0.27 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.015 (3)

Special details

Experimental. Crystal-to-detector distance 30 mm.

The ¹H NMR spectra were recorded with a Bruker DPX 200 instrument and referenced internally using the residual protonated solvent resonances relative to tetramethylsilane (δ = 0 p.p.m.).

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. Structure solved by direct methods and subsequent Fourier-difference synthesis. All non-hydrogen atoms were refined with anisotropic displacement parameters. The H atoms bound to O atoms were found on a Fourier-difference map and all the other ones were introduced at calculated positions. All H atoms were treated as riding atoms with an isotropic displacement parameter equal to 1.2 (OH, CH) or 1.5 (CH₃) times that of the parent atom. 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	0.3529 (2)	0.65970 (5)	0.64749 (16)	0.0248 (3)
O2	0.0454 (3)	0.66304 (6)	0.36142 (17)	0.0303 (4)
O3	−0.2079 (3)	0.71846 (6)	0.47425 (17)	0.0293 (3)
O4	0.2147 (3)	0.54022 (6)	0.4495 (2)	0.0453 (5)
O5	0.5479 (2)	0.59103 (6)	0.44315 (17)	0.0290 (3)
O7	0.2138 (2)	0.53501 (6)	0.92353 (18)	0.0312 (4)
O6	−0.1904 (2)	0.54079 (5)	0.85423 (17)	0.0277 (3)
H6	−0.2114	0.5129	0.9292	0.033*
O8	−0.0659 (3)	0.64074 (6)	1.04181 (18)	0.0378 (4)
H8	−0.0283	0.6509	1.1485	0.045*
O9	0.2176 (3)	0.69924 (6)	0.98835 (18)	0.0355 (4)
C1	0.1246 (3)	0.68552 (8)	0.6484 (2)	0.0231 (4)
H1	0.1503	0.7213	0.6917	0.028*
C2	0.3148 (4)	0.60390 (7)	0.6646 (2)	0.0245 (4)
H2	0.4336	0.5904	0.7528	0.029*
C3	0.0560 (3)	0.59640 (7)	0.7139 (2)	0.0224 (4)
H3	−0.0514	0.5864	0.6151	0.027*
C4	−0.0164 (3)	0.65307 (7)	0.7631 (2)	0.0226 (4)
H4	−0.1926	0.6585	0.7365	0.027*
C5	−0.0140 (4)	0.68757 (7)	0.4773 (2)	0.0246 (4)
C6	−0.3753 (4)	0.72008 (9)	0.3231 (3)	0.0350 (5)
H6A	−0.2870	0.7294	0.2331	0.052*
H6B	−0.5002	0.7458	0.3336	0.052*
H6C	−0.4489	0.6861	0.3032	0.052*
C7	0.3475 (4)	0.57477 (8)	0.5061 (2)	0.0278 (5)
C8	0.5976 (4)	0.56460 (9)	0.2924 (3)	0.0385 (5)
H8A	0.5590	0.5279	0.2992	0.058*
H8B	0.7672	0.5685	0.2784	0.058*
H8C	0.4992	0.5800	0.2003	0.058*
C9	0.0358 (4)	0.55437 (7)	0.8417 (2)	0.0246 (4)
C10	0.0630 (4)	0.66716 (8)	0.9420 (2)	0.0260 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0246 (7)	0.0219 (7)	0.0278 (7)	−0.0006 (5)	0.0029 (6)	0.0017 (6)
O2	0.0327 (8)	0.0354 (8)	0.0227 (8)	0.0049 (6)	0.0030 (6)	−0.0016 (6)
O3	0.0297 (7)	0.0328 (8)	0.0243 (7)	0.0063 (6)	−0.0015 (6)	0.0009 (6)
O4	0.0433 (9)	0.0415 (10)	0.0545 (11)	−0.0149 (8)	0.0203 (8)	−0.0206 (8)
O5	0.0273 (7)	0.0332 (8)	0.0270 (7)	−0.0025 (6)	0.0062 (6)	−0.0030 (6)
O7	0.0270 (7)	0.0333 (8)	0.0330 (8)	0.0015 (6)	0.0015 (6)	0.0102 (6)
O6	0.0239 (7)	0.0287 (8)	0.0305 (8)	−0.0027 (6)	0.0023 (6)	0.0064 (6)
O8	0.0509 (10)	0.0420 (9)	0.0213 (7)	−0.0136 (7)	0.0070 (7)	−0.0028 (6)
O9	0.0397 (9)	0.0392 (9)	0.0270 (8)	−0.0091 (7)	0.0016 (7)	−0.0027 (6)
C1	0.0239 (9)	0.0234 (10)	0.0219 (10)	0.0015 (8)	0.0018 (8)	0.0004 (7)
C2	0.0258 (10)	0.0217 (9)	0.0257 (10)	0.0007 (8)	0.0011 (8)	0.0021 (8)
C3	0.0241 (10)	0.0225 (10)	0.0206 (9)	0.0002 (7)	0.0025 (8)	0.0016 (7)
C4	0.0222 (9)	0.0244 (10)	0.0210 (10)	0.0002 (8)	0.0013 (8)	0.0009 (8)
C5	0.0262 (10)	0.0241 (10)	0.0238 (10)	−0.0015 (8)	0.0039 (8)	0.0029 (8)
C6	0.0317 (11)	0.0423 (13)	0.0293 (11)	0.0040 (10)	−0.0035 (10)	0.0051 (9)
C7	0.0272 (10)	0.0277 (10)	0.0288 (11)	0.0016 (8)	0.0044 (9)	0.0018 (8)
C8	0.0406 (13)	0.0437 (13)	0.0333 (12)	−0.0032 (10)	0.0125 (10)	−0.0071 (10)
C9	0.0261 (10)	0.0229 (10)	0.0251 (10)	0.0010 (8)	0.0042 (9)	−0.0007 (8)
C10	0.0295 (10)	0.0250 (10)	0.0235 (10)	0.0024 (8)	0.0029 (8)	0.0014 (8)

Geometric parameters (Å, º)

O1—C1	1.420 (2)	C1—H1	0.9800
O1—C2	1.443 (2)	C2—C7	1.524 (3)
O2—C5	1.212 (2)	C2—C3	1.539 (3)
O3—C5	1.324 (2)	C2—H2	0.9800
O3—C6	1.457 (2)	C3—C9	1.509 (3)
O4—C7	1.202 (3)	C3—C4	1.560 (3)
O5—C7	1.337 (2)	C3—H3	0.9800
O5—C8	1.460 (3)	C4—C10	1.523 (3)
O7—C9	1.225 (2)	C4—H4	0.9800
O6—C9	1.309 (2)	C6—H6A	0.9600
O6—H6	0.9540	C6—H6B	0.9600
O8—C10	1.326 (2)	C6—H6C	0.9600
O8—H8	0.9128	C8—H8A	0.9600
O9—C10	1.209 (2)	C8—H8B	0.9600
C1—C5	1.518 (3)	C8—H8C	0.9600
C1—C4	1.529 (3)
C1—O1—C2	108.33 (14)	C1—C4—H4	110.4
C5—O3—C6	117.59 (16)	C3—C4—H4	110.4
C7—O5—C8	115.38 (16)	O2—C5—O3	125.49 (18)
C9—O6—H6	115.7	O2—C5—C1	123.60 (18)
C10—O8—H8	111.7	O3—C5—C1	110.90 (16)
O1—C1—C5	111.28 (15)	O3—C6—H6A	109.5
O1—C1—C4	105.52 (14)	O3—C6—H6B	109.5
C5—C1—C4	110.45 (15)	H6A—C6—H6B	109.5
O1—C1—H1	109.8	O3—C6—H6C	109.5
C5—C1—H1	109.8	H6A—C6—H6C	109.5
C4—C1—H1	109.8	H6B—C6—H6C	109.5
O1—C2—C7	111.21 (16)	O4—C7—O5	124.75 (19)
O1—C2—C3	107.30 (15)	O4—C7—C2	123.88 (19)
C7—C2—C3	111.63 (16)	O5—C7—C2	111.30 (17)
O1—C2—H2	108.9	O5—C8—H8A	109.5
C7—C2—H2	108.9	O5—C8—H8B	109.5
C3—C2—H2	108.9	H8A—C8—H8B	109.5
C9—C3—C2	114.51 (16)	O5—C8—H8C	109.5
C9—C3—C4	115.64 (16)	H8A—C8—H8C	109.5
C2—C3—C4	103.06 (15)	H8B—C8—H8C	109.5
C9—C3—H3	107.7	O7—C9—O6	124.09 (18)
C2—C3—H3	107.7	O7—C9—C3	123.07 (18)
C4—C3—H3	107.7	O6—C9—C3	112.83 (16)
C10—C4—C1	110.82 (16)	O9—C10—O8	123.77 (18)
C10—C4—C3	114.34 (15)	O9—C10—C4	125.09 (18)
C1—C4—C3	100.12 (15)	O8—C10—C4	111.11 (16)
C10—C4—H4	110.4
O1—C1—C4—C3	−39.85 (17)	O1—C1—C5—O2	11.0 (3)
O1—C2—C3—C4	−13.31 (19)	C4—C1—C5—O2	−105.9 (2)
C1—O1—C2—C3	−12.0 (2)	O1—C1—C5—O3	−170.41 (15)
C2—O1—C1—C4	33.32 (18)	C4—C1—C5—O3	72.7 (2)
C2—C3—C4—C1	31.15 (18)	C8—O5—C7—O4	1.6 (3)
C2—O1—C1—C5	−86.50 (18)	C8—O5—C7—C2	178.87 (17)
C1—O1—C2—C7	110.33 (17)	O1—C2—C7—O4	−137.2 (2)
O1—C2—C3—C9	−139.76 (16)	C3—C2—C7—O4	−17.4 (3)
C7—C2—C3—C9	98.2 (2)	O1—C2—C7—O5	45.5 (2)
C7—C2—C3—C4	−135.39 (16)	C3—C2—C7—O5	165.28 (15)
O1—C1—C4—C10	81.20 (18)	C2—C3—C9—O7	13.8 (3)
C5—C1—C4—C10	−158.43 (16)	C4—C3—C9—O7	−105.8 (2)
C5—C1—C4—C3	80.52 (18)	C2—C3—C9—O6	−165.65 (16)
C9—C3—C4—C10	38.4 (2)	C4—C3—C9—O6	74.7 (2)
C2—C3—C4—C10	−87.34 (19)	C1—C4—C10—O9	−0.6 (3)
C9—C3—C4—C1	156.87 (16)	C3—C4—C10—O9	111.7 (2)
C6—O3—C5—O2	5.2 (3)	C1—C4—C10—O8	177.37 (16)
C6—O3—C5—C1	−173.42 (16)	C3—C4—C10—O8	−70.4 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O6—H6···O7^i	0.95	1.72	2.6649 (19)	173
O8—H8···O2^ii	0.91	1.77	2.681 (2)	174

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