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The crystal structure determination of the title compound, C13H15IO4, has allowed the relative stereochemistry between the tetrasubstituted C atoms on the tetra­hydro­furan moiety to be confirmed. The title compound is a precursor of the ionophoric antibiotic Aplasmomycin. The compound is involved in both intra- and intermolecular hydrogen bonding, the latter link the mol­ecules into chains running along the b axis.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536800018614/na6012sup1.cif
Contains datablocks 2, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536800018614/na60122sup2.hkl
Contains datablock 2

CCDC reference: 155889

Key indicators

  • Single-crystal X-ray study
  • T = 293 K
  • Mean [sigma](C-C) = 0.007 Å
  • R factor = 0.027
  • wR factor = 0.063
  • Data-to-parameter ratio = 13.3

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry

General Notes

REFLT_03 From the CIF: _diffrn_reflns_theta_max 25.03 From the CIF: _reflns_number_total 2233 Count of symmetry unique reflns 1446 Completeness (_total/calc) 154.43% TEST3: Check Friedels for noncentro structure Estimate of Friedel pairs measured 787 Fraction of Friedel pairs measured 0.544 Are heavy atom types Z>Si present yes 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.

Comment top

The title compound, (2), was synthesized as part of an ongoing synthetic project towards the synthesis of the C2-symmetric boron-containing antibiotic Aplasmomycin (Scheme 1; Knight et al., 2000). Aplasmomycin and its congeners are metabolites of Streptomyces griseus and are a unique family of boron-containing ionophoric antibiotics which show activity against Gram-positive bacteria. To date, two total and two formal syntheses of Aplasmomycin have been reported (Corey et al., 1982; White et al., 1986; Nakata et al., 1986; Matsuda et al., 1990).

Tetrahydrofuran (1) differentially appended at the 2-, 4- and 5-positions is a crucial component of Aplasmomycin. The precursor to (1) in our prospective synthesis of the natural product required tetrahydrofuran (2). 3-Iodotetrahydrofuran, (2) was readily synthesized in three steps using commercially available hexa-2,4-dien-1-ol as the starting material. Esterification of this with benzoyl chloride yielded quantitatively the ester (2) (Scheme 2), reaction of which under Sharpless asymmetric dihydroxylation conditions (273 K, aqueous t-BuOH; 1:1, 0.004 eqn K2OsO4, 0.01 eqn DHQD-PHAL, 3 eqn K3Fe(CN)6, 3 eqn K2CO3, 1 eqn MeSO2NH2) yielded diol (4) (55%). Finally, treatment of diol (4) under anhydrous conditions with 2 eqn of iodine monobromide (263 K) gave (2) via a 5-endo-trig iodocyclization (Knight et al., 1999, 2000). Subsequent deiodination (Bu3SnH, AlBN) and Mitsunobu mediated alcohol inversion (DIAD, PPh3, p-nitrobenzoic acid) yielded precursor the tetrahydrofuran (1) (Scheme 2).

To our knowledge, this is the first reported crystal structure determination of a 2,3,4,5-tetrasubstituted furan appended with a hydroxymethyl group (esterified), an I atom, a hydroxyl and a methyl group. The X-ray determination was necessary to confirm the stereochemistry as NMR coupling constant data was ambiguous and NOE data only was considered insufficient upon which to base the subsequent synthetic plans.

The title molecule is involved in both intra- and intermolecular hydrogen bonding. An interaction between the hydroxyl H atom of O4 and the O atom of the tetrahydrofuran links the molecules into chains running along the b axis. The large deviation from linearity of this bond [132 (5)°] is a direct result of an additional competitive interaction between the same hydrogen and I1.

The tetrahydrofuran ring is puckered in an envelope form with C11 deviating by -0.640 (6) Å from the plane of the remaining four atoms. The conformation around the sp3 atoms C8 and C9 is almost perfectly staggered [O3—C9—C8—O2 = 173.2 (4)°] such that O3 and O2 adopt a trans configuration.

There are four chiral centres in the molecule all within the tetrahydrofuran ring; C9 = R, C10 = S, C11 = S and C12 = R.

Experimental top

To a 50 ml flame-dried round-bottomed flask equipped with a stirrer-bead and a suba-seal was added 500 mg (2.11 mmol) of (4). Diol (4) was dissolved in 25 ml of dry acetonitrile (Perrin & Armarego, 1988; acetonitrile refluxed and distilled from calcium hydride under argon, according to the procedure stated in the reference). To the cold (263 K) stirred solution, under argon, was added solid iodine monobromide in one portion (873 mg, 4.22 mmol, 2 equivalents). The resulting solution was stirred at 263 K in the dark under argon (flask wrapped in aluminium foil). After 16 h, TLC analysis indicated that all of the starting material had been consummed (eluent; ether: petrol, 1:1). The crude reaction mixture was stripped of the acetonitrile in vacuo (bath temperature no higher than 308 K) and replaced with 50 ml of dichloromethane. The dichloromethane solution was washed with water (3 x 50 ml), then with 2.5 M aqueous sodium thiosulfate (2 x 75 ml) and finally with saturated brine solution (50 ml) before being dried (MgSO4), filtered and the solvent removed in vacuo. The crude product was purified via flash column chromatography (silica gel) using 1:1 pentane/ether as eluent. The title compound was obtained as a white solid (595 mg, 78%). Suitable crystals were grown by dissolving the purified product in a small amount of pure solvent and then allowing the solvent to evaporate slowly.

Computing details top

Data collection: DENZO (Otwinoski & Minor, 1997) and COLLECT (Hooft, 1998); cell refinement: DENZO and COLLECT; data reduction: DENZO (Otwinoski & Minor, 1997), COLLECT (Hooft, 1998) and maXus (Mackay et al., 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: CAMERON (Watkin et al., 1993); software used to prepare material for publication: WinGX (Farrugia, 1998).

Figures top
[Figure 1]
Fig. 1. View of (I) (50% probability displacement ellipsoids)

Fig. 2. Packing diagram of (I) showing the hydrogen-bonded chains viewed looking down the a axis.
(2R,3S,4S,5R)-4-Hydroxy-3-iodo-5-methyltetrahydro-2-furylmethyl benzoate top
Crystal data top
C13H15IO4Dx = 1.774 Mg m3
Mr = 362.15Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, P212121Cell parameters from 4354 reflections
a = 4.797 (1) Åθ = 3.1–25.0°
b = 11.886 (2) ŵ = 2.37 mm1
c = 23.775 (5) ÅT = 293 K
V = 1355.6 (5) Å3Block, colourless
Z = 40.5 × 0.3 × 0.3 mm
F(000) = 712
Data collection top
Nonius Kappa CCD area-detector
diffractometer
2233 independent reflections
Radiation source: Nonius FR591 roating anode2051 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.025
Detector resolution: 9.091 pixels per mm pixels mm-1θmax = 25.0°, θmin = 3.1°
Φ and ω scans to fill Ewald sphereh = 44
Absorption correction: empirical (using intensity measurements)
(SORTAV; Blessing, 1997)
k = 1413
Tmin = 0.352, Tmax = 0.492l = 2828
4354 measured reflections
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.027H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.063 w = 1/[σ2(Fo2) + (0.0282P)2 + 0.4539P]
where P = (Fo2 + 2Fc2)/3
S = 1.05(Δ/σ)max = 0.001
2233 reflectionsΔρmax = 0.72 e Å3
168 parametersΔρmin = 0.55 e Å3
0 restraintsAbsolute structure: Flack (1983), 888 Friedel pairs
Primary atom site location: structure-invariant direct methodsAbsolute structure parameter: 0.03 (3)
Crystal data top
C13H15IO4V = 1355.6 (5) Å3
Mr = 362.15Z = 4
Orthorhombic, P212121Mo Kα radiation
a = 4.797 (1) ŵ = 2.37 mm1
b = 11.886 (2) ÅT = 293 K
c = 23.775 (5) Å0.5 × 0.3 × 0.3 mm
Data collection top
Nonius Kappa CCD area-detector
diffractometer
2233 independent reflections
Absorption correction: empirical (using intensity measurements)
(SORTAV; Blessing, 1997)
2051 reflections with I > 2σ(I)
Tmin = 0.352, Tmax = 0.492Rint = 0.025
4354 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.027H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.063Δρmax = 0.72 e Å3
S = 1.05Δρmin = 0.55 e Å3
2233 reflectionsAbsolute structure: Flack (1983), 888 Friedel pairs
168 parametersAbsolute structure parameter: 0.03 (3)
0 restraints
Special details top

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 (Å2) top
xyzUiso*/Ueq
I10.40247 (7)0.20383 (3)0.852844 (15)0.05541 (12)
O10.5551 (11)0.6736 (3)0.89771 (18)0.0775 (14)
O20.4991 (7)0.4940 (2)0.87391 (14)0.0472 (9)
O30.0307 (6)0.4609 (3)0.75426 (13)0.0404 (7)
O40.0168 (7)0.2208 (3)0.74347 (16)0.0477 (9)
C10.8711 (11)0.4210 (4)0.95431 (19)0.0453 (11)
C21.0587 (12)0.3875 (4)0.9944 (2)0.0572 (13)
C31.1650 (12)0.4635 (5)1.0328 (2)0.0594 (15)
C41.0786 (14)0.5744 (5)1.0309 (2)0.0669 (17)
C50.8964 (12)0.6080 (4)0.9903 (2)0.0569 (13)
C60.7911 (11)0.5330 (4)0.95095 (19)0.0416 (11)
C70.6028 (11)0.5756 (4)0.90635 (19)0.0442 (10)
C80.3295 (11)0.5290 (4)0.8267 (2)0.0484 (13)
C90.1718 (9)0.4273 (3)0.80525 (18)0.0347 (10)
C120.1404 (10)0.3961 (4)0.70741 (18)0.0363 (10)
C100.3589 (10)0.3286 (3)0.78875 (19)0.0350 (9)
C110.2269 (9)0.2845 (3)0.73469 (18)0.0354 (9)
C130.0690 (11)0.3878 (4)0.66103 (18)0.0465 (11)
H10.79740.36870.92930.054*
H21.11510.31270.99580.069*
H31.29360.44031.05960.071*
H41.14460.62581.05720.08*
H50.84130.6830.98890.068*
H8A0.44670.55940.79710.058*
H8B0.19950.5870.83840.058*
H90.03520.40290.83340.042*
H100.54440.35810.77970.042*
H110.36240.24380.71150.042*
H120.30750.43380.6930.044*
H13A0.23060.34820.67430.07*
H13B0.0110.34780.62990.07*
H13C0.12180.4620.64920.07*
H040.010 (11)0.169 (4)0.763 (2)0.044 (16)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
I10.0693 (2)0.03275 (13)0.0641 (2)0.00100 (16)0.01865 (18)0.00937 (15)
O10.117 (4)0.0328 (17)0.083 (3)0.001 (2)0.051 (3)0.0026 (17)
O20.061 (2)0.0270 (14)0.0539 (19)0.0014 (13)0.0227 (15)0.0016 (13)
O30.0412 (19)0.0332 (15)0.0468 (17)0.0098 (13)0.0074 (14)0.0061 (13)
O40.048 (2)0.0351 (18)0.060 (2)0.0117 (14)0.0146 (16)0.0041 (16)
C10.053 (3)0.037 (2)0.046 (3)0.001 (2)0.004 (2)0.0019 (19)
C20.067 (4)0.048 (3)0.057 (3)0.001 (3)0.012 (3)0.008 (2)
C30.058 (4)0.071 (4)0.049 (3)0.010 (3)0.014 (2)0.017 (3)
C40.086 (5)0.054 (3)0.060 (3)0.012 (3)0.031 (4)0.002 (3)
C50.071 (4)0.038 (2)0.062 (3)0.005 (3)0.019 (3)0.006 (2)
C60.048 (3)0.039 (2)0.038 (2)0.003 (2)0.001 (2)0.0042 (19)
C70.051 (3)0.033 (2)0.048 (2)0.000 (2)0.009 (2)0.0000 (18)
C80.060 (4)0.027 (2)0.057 (3)0.004 (2)0.019 (2)0.0029 (19)
C90.038 (3)0.0286 (19)0.037 (2)0.0003 (17)0.0046 (17)0.0003 (17)
C100.029 (3)0.0263 (18)0.050 (2)0.0020 (16)0.0050 (19)0.0010 (16)
C110.033 (2)0.028 (2)0.045 (2)0.0030 (19)0.0024 (18)0.0029 (19)
C120.029 (3)0.037 (2)0.042 (2)0.0019 (19)0.0074 (19)0.0040 (18)
C130.052 (3)0.048 (2)0.039 (2)0.010 (2)0.007 (2)0.0006 (19)
Geometric parameters (Å, º) top
I1—C102.137 (4)C5—C61.388 (6)
O2—C81.447 (5)C7—O11.205 (5)
O3—C91.445 (5)C7—O21.335 (5)
O3—C121.453 (5)C7—C61.482 (7)
O4—C111.408 (5)C9—C81.514 (6)
C1—C21.371 (7)C9—C101.528 (6)
C1—C61.387 (6)C10—C111.526 (6)
C2—C31.381 (7)C12—C131.495 (6)
C3—C41.382 (8)C12—C111.534 (6)
C5—C41.362 (7)
O1—C7—O2122.2 (4)C2—C1—C6120.1 (5)
O1—C7—C6124.6 (4)C2—C3—C4119.5 (5)
O2—C7—C6113.1 (4)C4—C5—C6121.5 (5)
O2—C8—C9108.2 (3)C5—C6—C7119.0 (4)
O3—C9—C8107.2 (3)C5—C4—C3119.7 (5)
O3—C9—C10105.8 (3)C7—O2—C8116.7 (3)
O3—C12—C13110.9 (4)C8—C9—C10114.0 (4)
O3—C12—C11103.4 (3)C9—O3—C12109.1 (3)
O4—C11—C10113.9 (4)C9—C10—I1114.0 (3)
O4—C11—C12107.6 (3)C10—C11—C1299.8 (3)
C1—C6—C5118.5 (5)C11—C10—C9103.7 (3)
C1—C6—C7122.5 (4)C11—C10—I1113.7 (3)
C1—C2—C3120.8 (5)C13—C12—C11115.9 (4)
O3—C9—C8—O2173.2 (4)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O4—H04···O3i0.78 (5)2.51 (5)3.090 (4)132 (5)
O4—H04···I10.78 (5)2.88 (5)3.294 (3)115 (4)
Symmetry code: (i) x, y1/2, z+3/2.

Experimental details

Crystal data
Chemical formulaC13H15IO4
Mr362.15
Crystal system, space groupOrthorhombic, P212121
Temperature (K)293
a, b, c (Å)4.797 (1), 11.886 (2), 23.775 (5)
V3)1355.6 (5)
Z4
Radiation typeMo Kα
µ (mm1)2.37
Crystal size (mm)0.5 × 0.3 × 0.3
Data collection
DiffractometerNonius Kappa CCD area-detector
diffractometer
Absorption correctionEmpirical (using intensity measurements)
(SORTAV; Blessing, 1997)
Tmin, Tmax0.352, 0.492
No. of measured, independent and
observed [I > 2σ(I)] reflections
4354, 2233, 2051
Rint0.025
(sin θ/λ)max1)0.595
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.027, 0.063, 1.05
No. of reflections2233
No. of parameters168
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.72, 0.55
Absolute structureFlack (1983), 888 Friedel pairs
Absolute structure parameter0.03 (3)

Computer programs: DENZO (Otwinoski & Minor, 1997) and COLLECT (Hooft, 1998), DENZO and COLLECT, DENZO (Otwinoski & Minor, 1997), COLLECT (Hooft, 1998) and maXus (Mackay et al., 1998), SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), CAMERON (Watkin et al., 1993), WinGX (Farrugia, 1998).

Selected geometric parameters (Å, º) top
I1—C102.137 (4)C5—C61.388 (6)
O2—C81.447 (5)C7—O11.205 (5)
O3—C91.445 (5)C7—O21.335 (5)
O3—C121.453 (5)C7—C61.482 (7)
O4—C111.408 (5)C9—C81.514 (6)
C1—C21.371 (7)C9—C101.528 (6)
C1—C61.387 (6)C10—C111.526 (6)
C2—C31.381 (7)C12—C131.495 (6)
C3—C41.382 (8)C12—C111.534 (6)
C5—C41.362 (7)
O1—C7—O2122.2 (4)C2—C1—C6120.1 (5)
O1—C7—C6124.6 (4)C2—C3—C4119.5 (5)
O2—C7—C6113.1 (4)C4—C5—C6121.5 (5)
O2—C8—C9108.2 (3)C5—C6—C7119.0 (4)
O3—C9—C8107.2 (3)C5—C4—C3119.7 (5)
O3—C9—C10105.8 (3)C7—O2—C8116.7 (3)
O3—C12—C13110.9 (4)C8—C9—C10114.0 (4)
O3—C12—C11103.4 (3)C9—O3—C12109.1 (3)
O4—C11—C10113.9 (4)C9—C10—I1114.0 (3)
O4—C11—C12107.6 (3)C10—C11—C1299.8 (3)
C1—C6—C5118.5 (5)C11—C10—C9103.7 (3)
C1—C6—C7122.5 (4)C11—C10—I1113.7 (3)
C1—C2—C3120.8 (5)C13—C12—C11115.9 (4)
O3—C9—C8—O2173.2 (4)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O4—H04···O3i0.78 (5)2.51 (5)3.090 (4)132 (5)
O4—H04···I10.78 (5)2.88 (5)3.294 (3)115 (4)
Symmetry code: (i) x, y1/2, z+3/2.
 

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