(1R*,5S*,6S*,7R*)-6,7-Di­hydroxy-6-hydroxy­methyl-2-oxabi­cyclo­[3.2.0]­heptan-3-one

The crystal structure analysis of the title compound, C₇H₁₀O₅, shows that a four-five lactonization instead of a four-six self condensation took place during the reaction sequence. The structure is stabilized by strong hydrogen-bonding interactions that serve to form a layer structure. The absolute configuration was assigned based on the chemical synthesis from a starting material of known chirality.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.030
• wR factor = 0.072
• Data-to-parameter ratio = 8.7

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level C:



STRVAL_01
         From the CIF: _refine_ls_abs_structure_Flack  -10.000
         From the CIF: _refine_ls_abs_structure_Flack_su   10.000
           Alert C Flack parameter is too small

General Notes



REFLT_03
         From the CIF: _diffrn_reflns_theta_max           28.30
         From the CIF: _reflns_number_total               1107
         Count of symmetry unique reflns         1105
         Completeness (_total/calc)            100.18%
         TEST3: Check Friedels for noncentro structure
         Estimate of Friedel pairs measured         2
         Fraction of Friedel pairs measured     0.002
         Are heavy atom types Z>Si present           no
          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.


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 1 Alert Level C = Please check

---

Computing details

Data collection: SMART-NT (Bruker, 1998); cell refinement: SAINT-Plus (Bruker, 1999); data reduction: SAINT-Plus and XPREP (Bruker, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg & Berndt, 2000); software used to prepare material for publication: SHELXL97.

(1R*,5S*,6S*,7R*)-6,7-Dihydroxy-6-hydroxymethyl-2-oxabicyclo[3.2.0]heptan-3-one

Crystal data

C7H10O5	F(000) = 368
Mr = 174.15	Dx = 1.543 Mg m^−3
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 698 reflections
a = 6.5888 (9) Å	θ = 3.8–26.9°
b = 7.4342 (10) Å	µ = 0.13 mm^−1
c = 15.303 (2) Å	T = 293 K
V = 749.59 (17) Å^3	Cuboid, colorless
Z = 4	0.46 × 0.26 × 0.18 mm

Data collection

SMART CCD 1K area-detector diffractometer	897 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.038
Graphite monochromator	θmax = 28.3°, θmin = 2.7°
ω scans	h = −8→8
5322 measured reflections	k = −8→9
1107 independent reflections	l = −18→20

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)] = 0.030	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.072	w = 1/[σ^2(Fo^2) + (0.0441P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.00	(Δ/σ)max < 0.001
1107 reflections	Δρmax = 0.15 e Å^−3
127 parameters	Δρmin = −0.16 e Å^−3
0 restraints	Absolute structure: Flack (1983), 744 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −10 (10)

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
O5	−0.114852 (2)	0.2488 (2)	0.86512 (9)	0.0403 (4)
O1	0.2810 (2)	0.37971 (17)	0.84311 (9)	0.0370 (4)
O2	0.3558 (2)	0.01718 (19)	0.71149 (8)	0.0332 (3)
O3	0.3195 (2)	−0.20206 (16)	0.86719 (9)	0.0370 (4)
O4	0.0636 (3)	−0.33747 (19)	0.93400 (11)	0.0529 (5)
C1	0.2408 (3)	0.1914 (2)	0.84292 (11)	0.0254 (4)
C5	0.1534 (3)	−0.0307 (3)	0.97439 (12)	0.0339 (4)
H5A	0.1886	−0.0460	1.0355	0.041*
H5B	0.0173	0.0185	0.9705	0.041*
C7	0.0270 (3)	0.1583 (3)	0.81039 (12)	0.0288 (4)
H7A	0.0139	0.2017	0.7509	0.035*
H7B	−0.0012	0.0302	0.8106	0.035*
C2	0.4075 (3)	0.0876 (2)	0.79413 (12)	0.0263 (4)
C4	0.3054 (3)	0.0914 (2)	0.92869 (12)	0.0301 (4)
C3	0.4357 (3)	−0.0373 (2)	0.87276 (13)	0.0309 (4)
C6	0.1678 (3)	−0.2052 (3)	0.92644 (12)	0.0338 (4)
H21	0.518 (4)	0.161 (3)	0.7918 (14)	0.041*
H31	0.571 (3)	−0.070 (3)	0.8904 (14)	0.041*
H41	0.382 (3)	0.161 (3)	0.9698 (15)	0.041*
H02	0.461 (4)	−0.014 (3)	0.6925 (15)	0.041*
H05	−0.169 (4)	0.339 (3)	0.8313 (14)	0.041*
H01	0.207 (4)	0.429 (3)	0.8692 (15)	0.041*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O5	0.0326 (7)	0.0473 (8)	0.0410 (7)	0.0118 (7)	0.0053 (6)	0.0020 (7)
O1	0.0380 (8)	0.0200 (7)	0.0530 (10)	−0.0014 (5)	0.0132 (7)	−0.0043 (6)
O2	0.0296 (7)	0.0371 (8)	0.0328 (7)	−0.0002 (6)	0.0044 (6)	−0.0087 (6)
O3	0.0465 (8)	0.0236 (7)	0.0407 (7)	0.0021 (6)	0.0143 (6)	0.0000 (6)
O4	0.0695 (11)	0.0344 (8)	0.0549 (10)	−0.0126 (8)	0.0225 (9)	−0.0022 (7)
C1	0.0281 (9)	0.0198 (9)	0.0284 (9)	−0.0029 (7)	0.0035 (7)	−0.0001 (7)
C5	0.0433 (11)	0.0319 (10)	0.0266 (8)	0.0031 (9)	0.0060 (8)	0.0007 (8)
C7	0.0296 (10)	0.0289 (10)	0.0281 (9)	0.0038 (8)	−0.0018 (7)	−0.0010 (8)
C2	0.0221 (9)	0.0235 (9)	0.0333 (10)	−0.0025 (7)	0.0020 (7)	−0.0023 (8)
C4	0.0333 (10)	0.0301 (10)	0.0268 (9)	−0.0023 (8)	−0.0052 (8)	−0.0043 (8)
C3	0.0261 (9)	0.0289 (10)	0.0378 (10)	0.0040 (8)	0.0001 (8)	0.0029 (9)
C6	0.0421 (11)	0.0288 (10)	0.0306 (10)	0.0026 (9)	0.0056 (8)	0.0049 (8)

Geometric parameters (Å, º)

O5—C7	1.424 (2)	C5—C6	1.493 (3)
O5—H05	0.92 (2)	C5—C4	1.521 (3)
O1—C1	1.425 (2)	C5—H5A	0.9700
O1—H01	0.73 (2)	C5—H5B	0.9700
O2—C2	1.411 (2)	C7—H7A	0.9700
O2—H02	0.79 (3)	C7—H7B	0.9700
O3—C6	1.350 (2)	C2—C3	1.531 (3)
O3—C3	1.447 (2)	C2—H21	0.91 (2)
O4—C6	1.205 (2)	C4—C3	1.544 (3)
C1—C7	1.514 (3)	C4—H41	0.96 (2)
C1—C2	1.536 (2)	C3—H31	0.97 (2)
C1—C4	1.568 (2)
C7—O5—H05	105.7 (14)	O2—C2—C3	120.59 (16)
C1—O1—H01	111.9 (17)	O2—C2—C1	116.71 (15)
C2—O2—H02	103.0 (17)	C3—C2—C1	90.56 (14)
C6—O3—C3	111.52 (15)	O2—C2—H21	112.4 (14)
O1—C1—C7	109.49 (15)	C3—C2—H21	107.4 (13)
O1—C1—C2	111.21 (15)	C1—C2—H21	106.7 (14)
C7—C1—C2	115.06 (14)	C5—C4—C3	104.55 (14)
O1—C1—C4	114.46 (15)	C5—C4—C1	119.27 (16)
C7—C1—C4	116.79 (15)	C3—C4—C1	88.91 (14)
C2—C1—C4	88.52 (13)	C5—C4—H41	111.5 (13)
C6—C5—C4	104.50 (15)	C3—C4—H41	113.9 (12)
C6—C5—H5A	110.9	C1—C4—H41	116.0 (12)
C4—C5—H5A	110.9	O3—C3—C2	113.75 (16)
C6—C5—H5B	110.9	O3—C3—C4	105.24 (14)
C4—C5—H5B	110.9	C2—C3—C4	89.55 (13)
H5A—C5—H5B	108.9	O3—C3—H31	107.0 (12)
O5—C7—C1	109.87 (14)	C2—C3—H31	119.1 (13)
O5—C7—H7A	109.7	C4—C3—H31	121.1 (13)
C1—C7—H7A	109.7	O4—C6—O3	120.02 (17)
O5—C7—H7B	109.7	O4—C6—C5	128.73 (17)
C1—C7—H7B	109.7	O3—C6—C5	111.24 (17)
H7A—C7—H7B	108.2