rac-(R)-2-[(2R,5R)-5-Methyl­tetra­hydro­furan-2-yl]propanoic acid

In the crystal structure of the title compound, C₈H₁₄O₃, the 2,5-tetra­hydro­furan ring junction is cis. The relative configuration of position 2 in the propanoic acid group was found to be the same as that in positions 2 and 5 in the tetra­hydro­furan ring. In the crystal structure, symmetry-related mol­ecules are linked by O—H...O hydrogen bonds to form centrosymmetric dimers.

Key indicators

• Single-crystal X-ray study
• T = 173 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.060
• wR factor = 0.186
• Data-to-parameter ratio = 22.4

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   0.117
PLAT020_ALERT_3_C The value of Rint is greater than 0.10 .........       0.12

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   2 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
   2 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: X-AREA (Stoe, 2005); cell refinement: X-AREA; data reduction: X-RED32 (Stoe, 2005); 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: SHELXL97.

rac-(R)-2-[(2R,5R)-5-Methyltetrahydrofuran-2-yl]propanoic acid

Crystal data

C8H14O3	F(000) = 344
Mr = 158.19	Dx = 1.226 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 5311 reflections
a = 8.7400 (17) Å	θ = 1.7–29.1°
b = 11.870 (3) Å	µ = 0.09 mm^−1
c = 9.2749 (16) Å	T = 173 K
β = 117.022 (13)°	Rod, colourless
V = 857.2 (3) Å^3	0.50 × 0.23 × 0.22 mm
Z = 4

Data collection

Stoe IPDS-2 diffractometer	1392 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.117
Graphite monochromator	θmax = 29.3°, θmin = 2.7°
Detector resolution: 0.81Å pixels mm^-1	h = −11→11
φ and ω scans	k = −16→16
10718 measured reflections	l = −11→12
2312 independent 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)] = 0.061	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.186	H-atom parameters constrained
S = 1.03	w = 1/[σ^2(Fo^2) + (0.1002P)^2] where P = (Fo^2 + 2Fc^2)/3
2312 reflections	(Δ/σ)max < 0.001
103 parameters	Δρmax = 0.21 e Å^−3
0 restraints	Δρmin = −0.28 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
O1	0.49353 (18)	0.40255 (10)	0.22475 (18)	0.0534 (4)
O2	0.86955 (19)	0.50750 (12)	0.29862 (18)	0.0557 (4)
O3	0.8165 (2)	0.55718 (13)	0.50323 (17)	0.0582 (4)
H3	0.9165	0.5321	0.5573	0.087*
C1	0.4611 (3)	0.51734 (15)	0.2490 (2)	0.0478 (4)
H1A	0.4681	0.5260	0.3591	0.057*
C2	0.2787 (3)	0.53823 (16)	0.1217 (2)	0.0523 (5)
H2A	0.2758	0.5637	0.0188	0.063*
H2B	0.2218	0.5954	0.1585	0.063*
C3	0.1936 (3)	0.42376 (18)	0.1019 (3)	0.0600 (5)
H3A	0.1321	0.4026	−0.0139	0.072*
H3B	0.1106	0.4246	0.1472	0.072*
C4	0.3399 (3)	0.34142 (16)	0.1950 (2)	0.0526 (5)
H4A	0.3413	0.3232	0.3008	0.063*
C5	0.3373 (4)	0.23442 (19)	0.1095 (3)	0.0694 (6)
H5C	0.2325	0.1923	0.0873	0.104*
H5B	0.4379	0.1889	0.1779	0.104*
H5A	0.3399	0.2518	0.0074	0.104*
C6	0.5969 (3)	0.58995 (14)	0.2363 (2)	0.0478 (5)
H6A	0.5835	0.5843	0.1236	0.057*
C7	0.5779 (3)	0.71407 (16)	0.2724 (3)	0.0591 (6)
H7C	0.6721	0.7580	0.2709	0.089*
H7B	0.5818	0.7201	0.3794	0.089*
H7A	0.4679	0.7432	0.1901	0.089*
C8	0.7733 (3)	0.54813 (14)	0.3524 (2)	0.0452 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0495 (8)	0.0365 (6)	0.0691 (9)	0.0027 (5)	0.0224 (7)	0.0056 (5)
O2	0.0567 (8)	0.0556 (8)	0.0535 (8)	0.0047 (6)	0.0239 (7)	−0.0013 (6)
O3	0.0588 (9)	0.0601 (8)	0.0475 (8)	0.0086 (7)	0.0170 (7)	−0.0042 (6)
C1	0.0544 (11)	0.0393 (9)	0.0456 (10)	0.0037 (7)	0.0191 (8)	0.0014 (7)
C2	0.0514 (11)	0.0449 (9)	0.0529 (11)	0.0054 (8)	0.0169 (9)	−0.0026 (8)
C3	0.0527 (12)	0.0571 (12)	0.0628 (13)	0.0010 (9)	0.0197 (10)	0.0068 (9)
C4	0.0558 (11)	0.0465 (10)	0.0544 (11)	−0.0034 (8)	0.0241 (9)	0.0031 (8)
C5	0.0802 (16)	0.0499 (11)	0.0840 (17)	−0.0113 (11)	0.0425 (13)	−0.0046 (11)
C6	0.0572 (11)	0.0375 (8)	0.0444 (10)	0.0032 (8)	0.0192 (8)	0.0013 (7)
C7	0.0708 (14)	0.0397 (9)	0.0615 (12)	0.0054 (9)	0.0253 (11)	0.0013 (8)
C8	0.0541 (11)	0.0330 (7)	0.0451 (10)	−0.0048 (7)	0.0195 (8)	−0.0028 (6)

Geometric parameters (Å, º)

O1—C1	1.430 (2)	C3—H3B	0.9900
O1—C4	1.438 (2)	C4—C5	1.492 (3)
O2—C8	1.253 (2)	C4—H4A	1.0000
O3—C8	1.277 (2)	C5—H5C	0.9800
O3—H3	0.8400	C5—H5B	0.9800
C1—C6	1.514 (3)	C5—H5A	0.9800
C1—C2	1.512 (3)	C6—C8	1.508 (3)
C1—H1A	1.0000	C6—C7	1.536 (3)
C2—C3	1.520 (3)	C6—H6A	1.0000
C2—H2A	0.9900	C7—H7C	0.9800
C2—H2B	0.9900	C7—H7B	0.9800
C3—C4	1.528 (3)	C7—H7A	0.9800
C3—H3A	0.9900
C1—O1—C4	106.04 (15)	C5—C4—H4A	109.1
C8—O3—H3	109.5	C3—C4—H4A	109.1
O1—C1—C6	108.16 (16)	C4—C5—H5C	109.5
O1—C1—C2	104.31 (15)	C4—C5—H5B	109.5
C6—C1—C2	115.54 (16)	H5C—C5—H5B	109.5
O1—C1—H1A	109.5	C4—C5—H5A	109.5
C6—C1—H1A	109.5	H5C—C5—H5A	109.5
C2—C1—H1A	109.5	H5B—C5—H5A	109.5
C1—C2—C3	103.44 (16)	C8—C6—C1	109.90 (15)
C1—C2—H2A	111.1	C8—C6—C7	109.65 (16)
C3—C2—H2A	111.1	C1—C6—C7	111.29 (17)
C1—C2—H2B	111.1	C8—C6—H6A	108.6
C3—C2—H2B	111.1	C1—C6—H6A	108.6
H2A—C2—H2B	109.0	C7—C6—H6A	108.6
C2—C3—C4	105.39 (17)	C6—C7—H7C	109.5
C2—C3—H3A	110.7	C6—C7—H7B	109.5
C4—C3—H3A	110.7	H7C—C7—H7B	109.5
C2—C3—H3B	110.7	C6—C7—H7A	109.5
C4—C3—H3B	110.7	H7C—C7—H7A	109.5
H3A—C3—H3B	108.8	H7B—C7—H7A	109.5
O1—C4—C5	108.59 (18)	O2—C8—O3	123.42 (18)
O1—C4—C3	104.75 (15)	O2—C8—C6	119.73 (17)
C5—C4—C3	115.95 (19)	O3—C8—C6	116.84 (18)
O1—C4—H4A	109.1
C4—O1—C1—C6	−165.11 (15)	O1—C1—C6—C8	−54.51 (19)
C4—O1—C1—C2	−41.6 (2)	C2—C1—C6—C8	−170.94 (16)
O1—C1—C2—C3	31.1 (2)	O1—C1—C6—C7	−176.17 (16)
C6—C1—C2—C3	149.68 (17)	C2—C1—C6—C7	67.4 (2)
C1—C2—C3—C4	−10.2 (2)	C1—C6—C8—O2	114.20 (19)
C1—O1—C4—C5	158.99 (17)	C7—C6—C8—O2	−123.16 (19)
C1—O1—C4—C3	34.5 (2)	C1—C6—C8—O3	−66.1 (2)
C2—C3—C4—O1	−13.9 (2)	C7—C6—C8—O3	56.5 (2)
C2—C3—C4—C5	−133.6 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3···O2^i	0.84	1.80	2.630 (2)	170

Symmetry code: (i) −x+2, −y+1, −z+1.