Issue contents
Download PDF of article
Download CIF
3D view
Navigation
Highlighting
Dictionary of Crystallography reference
IUPAC Gold Book reference
more ...
Download citation
FormatBIBTeX
EndNote
RefMan
Refer
Medline
CIF
SGML
Plain Text
share
Previous article
Next article
Previous article
Issue contents
Download PDF of article
Download CIF
3D view
Navigation
Highlighting
Dictionary of Crystallography reference
IUPAC Gold Book reference
more ...
Download citation
FormatBIBTeX
EndNote
RefMan
Refer
Medline
CIF
SGML
Plain Text
share
Next article

organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 69| Part 5| May 2013| Page o772
https://doi.org/10.1107/S1600536813010313

[(2S,3aR,6aR)-5-Oxohexa­hydro­furo[3,2-b]furan-2-yl]methyl acetate

María González,a Andrea Martínez,a Marcos L. Rivadullaa and Maria J. Matosb*

aDepartamento Quimica Organica, Facultade de Quimica, Universidade de Vigo, E-36310 Vigo, Spain, and bDepartamento Quimica Organica, Facultade de Farmacia, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
*Correspondence e-mail: mariacmatos@gmail.com

(Received 12 April 2013; accepted 15 April 2013; online 20 April 2013)

The title compound, C9H12O5, is a bicyclic lactone, presenting a 2,6-dioxabi­cyclo­[3.3.0]octan-3-one skeleton, which was obtained through an intra­molecular lactonization. The bicyclic lactone presents a cis ring-junction and a 1,5-trans-substituted tetra­hydro­furan. Both five-membered rings are in twisted envelope conformations with one of the fused C atoms as the flap. The dihedral angle between the mean planes of the bicyclic lactone residue, defined by the di­hydro­furan-2(3H)-one and the tetra­hydro­furan rings, is 69.5 (2)°. The atoms of the ester chain are coplanar [maximum deviation = 0.013 (2) Å]. The absolute structure was not determined.

Related literature

For the stereoselective synthesis, applications and structures of related 2,6-dioxabi­cyclo­[3.3.0]octan-3-ones, see: Agrawal et al. (2006[Agrawal, D., Sriramurthy, V. & Yadav, V. K. (2006). Tetrahedron Lett. 47, 7615-7618.]); Banda & Chakravarthy (2006[Banda, G. & Chakravarthy, I. E. (2006). Tetrahedron Asymmetry, 17, 1684-1687.]); Paddon-Jones et al. (2001[Paddon-Jones, G. C., McErlean, C. S. P., Hayes, P., Moore, C. J., Konig, W. A. & Kitching, W. (2001). J. Org. Chem. 66, 7487-7495.]). For the biological activity of target compounds, see: Hayes et al. (2003[Hayes, P. Y., Fletcher, M. T., Crow, S., McGrath, M. J., Tu, Y. Q., Zhang, H., Hungerford, N. L., McErlean, C. S. P., Stok, J. E., Moore, C. J., DeVoss, J. J. & Kitching, W. (2003). Quirality, 15, S116-S127.]). For the synthesis of chiral tetra­hydro­furans using L-malic acid, see: Álvarez et al. (2010[Álvarez, C., Pérez, M., Zúñiga, A., Gómez, G. & Fall, Y. (2010). Synthesis, 22, 3883-3890.]). For pseudorotation parameters, see: Rao et al. (1981[Rao, S. T., Westhof, E. & Sundaralingam, M. (1981). Acta Cryst. A37, 421-425.]).

[Scheme 1]

Experimental

Crystal data

  • C9H12O5

  • Mr = 200.19

  • Monoclinic, P 21

  • a = 10.015 (5) Å

  • b = 4.647 (3) Å

  • c = 10.904 (5) Å

  • β = 109.755 (7)°

  • V = 477.6 (4) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 0.12 mm−1

  • T = 293 K

  • 0.49 × 0.11 × 0.10 mm
Data collection

  • Bruker APEXII CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]) Tmin = 0.602, Tmax = 0.745

  • 2551 measured reflections

  • 1530 independent reflections

  • 1313 reflections with I > 2σ(I)

  • Rint = 0.028
Refinement

  • R[F2 > 2σ(F2)] = 0.044

  • wR(F2) = 0.097

  • S = 1.07

  • 1530 reflections

  • 128 parameters

  • 1 restraint

  • H-atom parameters constrained

  • Δρmax = 0.14 e Å−3

  • Δρmin = −0.16 e Å−3

Data collection: APEX2 (Bruker, 2007[Bruker (2007). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2007[Bruker (2007). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]).

Supporting information

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S1600536813010313/go2086sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536813010313/go2086Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S1600536813010313/go2086Isup3.cml

checkCIF report


Comment top

The 2,6-dioxabicyclo[3.3.0]octan-3-one skeleton is present in a number of natural products possessing diverse biological activities (Agrawal et al., 2006; Banda et al., 2006; Paddon-Jones et al., 2001). We have described a new methodology for the synthesis of chiral tetrahydrofurans using L-malic acid (Álvarez et al., 2010) as starting material. Using this strategy, a formal synthesis of (7S)-Hagen's gland lactones was achieved by an intramolecular lactonization protocol. These bicyclic lactones can be considered as potential bio-control agents for fruit-fly populations in different countries (Hayes et al., 2003). Analyzing the crystallographic data, it is observed that both five-membered rings are in twisted envelope conformations Fig.1. The pseudorotation parameters P and τ(M), (Rao et al., 1981), for the 5-membered ring containing O2 are P = 334.4 (4)°, τ(M) = 24.3 (2)°, for reference bond C5–C4, the closest pucker descriptor for this is an Envelope on C(5). The pseudorotation parameters P and τ(M) for the 5-membered ring containing O6 are P = 345.0 (4)°, τ(M) = 26.1 (2)°, for the reference bond C1–C8, the closest pucker descriptor for this is an Envelope on C1. The dihedral angle between the main planes of the bicyclic lactone residue is 69.52°. The dihedral angle between the tetrahydrofuran plane and the plane of the ester residue (defined as the C1'-O2'-C3'-C4' atoms) is 55.94°. The C1'-O2'-C3'-C4' atoms of the lateral chain are co-planar.

Related literature top

For the stereoselective synthesis, applications and structures of related 2,6-dioxabicyclo[3.3.0]octan-3-ones, see: Agrawal et al. (2006); Banda & Chakravarthy (2006); Paddon-Jones et al. (2001). For the biological activity of target compounds, see: Hayes et al. (2003). For the synthesis of chiral tetrahydrofurans using L-malic acid, see: Álvarez et al. (2010). For pseudorotation parameters, see: Rao et al. (1981).

Experimental top

To a solution of (1R, 5R,7S)-7-hydroxymethyl-2,6-dioxabicyclo[3.3.0]octan-3-one (0.158 mmol) in pyridine (226 mL) was added Ac2O (149 mL) and the mixture was stirred at r.t. for 2 h. MeOH (3 mL) as added and the stirring continued for 20 min. The solvent was evaporated and EtOAc (5 mL) was added. The organic layer was washed with aq Cu2SO4 (3 x 5 mL), dried and the solvent was removed by rotary evaporation affording the title compound. It was then recrystallized using EtOAc. [mp: 87.1 – 89.9 °C; IR (NaCl, neat): 2917, 2849, 1771, 1740, 1462, 1370 cm-1; 1H-NMR (CDCl3): δ: 5.14 (t, 1H, J=3.7 Hz), 4.86 (s, 1H), 4.40 (d, 1H, J=5.5 Hz), 4.27 (d, 1H, J=11.9 Hz), 4.06 (dd, 1H, J=6.0 Hz, J=11.8 Hz), 2.76 (m, 2H), 2.44 (dd, 2H, J=5.3 Hz, J=13.9 Hz), 2.11 (s, 3H); 13C-NMR (CDCl3): δ: 175.53 (C=O), 170.85 (C=O), 84.34 (CH), 78.56 (CH), 76.41 (CH), 65.28 (CH2), 36.62 (CH2), 34.99 (CH2), 20.85 (CH3); HRMS: calcd for C9H12NaO5: 223.0577; found: 223.0575].

Refinement top

In all compounds H atoms were treated as riding atoms with C—H(primary), 0.97Å, C—H(secondary), 0.98Å with Uiso = 1.2Ueq(C)and C—H(methyl), 0.96Å. The positions of the methyl hydrogens was checked on a difference map. Since only C,H and O atoms were present in the molecule the quoted Flack parameter is meaningless and hence the absolute structure could not be determined.

Structure description top

The 2,6-dioxabicyclo[3.3.0]octan-3-one skeleton is present in a number of natural products possessing diverse biological activities (Agrawal et al., 2006; Banda et al., 2006; Paddon-Jones et al., 2001). We have described a new methodology for the synthesis of chiral tetrahydrofurans using L-malic acid (Álvarez et al., 2010) as starting material. Using this strategy, a formal synthesis of (7S)-Hagen's gland lactones was achieved by an intramolecular lactonization protocol. These bicyclic lactones can be considered as potential bio-control agents for fruit-fly populations in different countries (Hayes et al., 2003). Analyzing the crystallographic data, it is observed that both five-membered rings are in twisted envelope conformations Fig.1. The pseudorotation parameters P and τ(M), (Rao et al., 1981), for the 5-membered ring containing O2 are P = 334.4 (4)°, τ(M) = 24.3 (2)°, for reference bond C5–C4, the closest pucker descriptor for this is an Envelope on C(5). The pseudorotation parameters P and τ(M) for the 5-membered ring containing O6 are P = 345.0 (4)°, τ(M) = 26.1 (2)°, for the reference bond C1–C8, the closest pucker descriptor for this is an Envelope on C1. The dihedral angle between the main planes of the bicyclic lactone residue is 69.52°. The dihedral angle between the tetrahydrofuran plane and the plane of the ester residue (defined as the C1'-O2'-C3'-C4' atoms) is 55.94°. The C1'-O2'-C3'-C4' atoms of the lateral chain are co-planar.

For the stereoselective synthesis, applications and structures of related 2,6-dioxabicyclo[3.3.0]octan-3-ones, see: Agrawal et al. (2006); Banda & Chakravarthy (2006); Paddon-Jones et al. (2001). For the biological activity of target compounds, see: Hayes et al. (2003). For the synthesis of chiral tetrahydrofurans using L-malic acid, see: Álvarez et al. (2010). For pseudorotation parameters, see: Rao et al. (1981).

Computing details top

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.
[(2S,3aR,6aR)-5-Oxohexahydrofuro[3,2-b]furan-2-yl]methyl acetate top
Crystal data top
C9H12O5Dx = 1.392 Mg m−3
Mr = 200.19Melting point: 360.15(4) K
Monoclinic, P21Mo Kα radiation, λ = 0.71073 Å
a = 10.015 (5) ÅCell parameters from 1040 reflections
b = 4.647 (3) Åθ = 2.4–24.1°
c = 10.904 (5) ŵ = 0.12 mm−1
β = 109.755 (7)°T = 293 K
V = 477.6 (4) Å3Needle, colourless
Z = 20.49 × 0.11 × 0.10 mm
F(000) = 212
Data collection top
Bruker APEXII CCD
diffractometer		1530 independent reflections
Radiation source: fine-focus sealed tube1313 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.028
φ and ω scansθmax = 25.1°, θmin = 2.0°
Absorption correction: multi-scan
(SADABS; Sheldrick, 2008)		h = −11→11
Tmin = 0.602, Tmax = 0.745k = −5→5
2551 measured reflectionsl = −13→12
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.044Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.097H-atom parameters constrained
S = 1.07 w = 1/[σ2(Fo2) + (0.0377P)2 + 0.1292P]
where P = (Fo2 + 2Fc2)/3
1530 reflections(Δ/σ)max < 0.001
128 parametersΔρmax = 0.14 e Å−3
1 restraintΔρmin = −0.16 e Å−3
Crystal data top
C9H12O5V = 477.6 (4) Å3
Mr = 200.19Z = 2
Monoclinic, P21Mo Kα radiation
a = 10.015 (5) ŵ = 0.12 mm−1
b = 4.647 (3) ÅT = 293 K
c = 10.904 (5) Å0.49 × 0.11 × 0.10 mm
β = 109.755 (7)°
Data collection top
Bruker APEXII CCD
diffractometer		1530 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 2008)		1313 reflections with I > 2σ(I)
Tmin = 0.602, Tmax = 0.745Rint = 0.028
2551 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0441 restraint
wR(F2) = 0.097H-atom parameters constrained
S = 1.07Δρmax = 0.14 e Å−3
1530 reflectionsΔρmin = −0.16 e Å−3
128 parameters
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
C10.3092 (3)0.6053 (7)0.9619 (3)0.0455 (7)
H10.36480.42730.98250.055*
O20.38327 (19)0.8441 (5)1.04241 (19)0.0546 (6)
C30.3280 (3)0.9021 (7)1.1363 (3)0.0518 (8)
O30.3786 (3)1.0867 (6)1.2155 (2)0.0788 (7)
C40.2033 (3)0.7134 (8)1.1221 (2)0.0522 (8)
H4A0.12330.82521.12650.063*
H4B0.22630.56741.18960.063*
O60.07106 (19)0.7479 (6)0.89421 (18)0.0656 (7)
C50.1713 (3)0.5796 (7)0.9901 (3)0.0459 (7)
H50.14070.37900.98870.055*
C70.1203 (3)0.8206 (7)0.7894 (3)0.0452 (7)
H70.13091.02990.78650.054*
C80.2656 (3)0.6782 (8)0.8200 (3)0.0530 (8)
H8A0.25890.50600.76790.064*
H8B0.33290.80950.80340.064*
C1'0.0167 (3)0.7196 (8)0.6629 (3)0.0487 (7)
H1A0.05500.74890.59320.058*
H1B−0.00250.51610.66770.058*
O2'−0.1124 (2)0.8846 (5)0.63829 (18)0.0533 (5)
C3'−0.2165 (3)0.8315 (7)0.5261 (3)0.0504 (7)
O3'−0.2036 (3)0.6670 (6)0.4477 (2)0.0807 (8)
C4'−0.3452 (3)1.0036 (8)0.5127 (3)0.0659 (10)
H4E−0.38930.93310.57250.099*
H4D−0.41040.98760.42520.099*
H4C−0.31921.20170.53180.099*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0348 (13)0.0492 (18)0.0516 (16)0.0035 (14)0.0136 (12)0.0035 (14)
O20.0410 (10)0.0622 (14)0.0599 (12)−0.0120 (11)0.0162 (9)−0.0041 (11)
C30.0467 (17)0.057 (2)0.0405 (16)0.0046 (16)0.0004 (13)0.0065 (15)
O30.0824 (16)0.0760 (18)0.0616 (14)−0.0014 (15)0.0029 (12)−0.0152 (14)
C40.0471 (16)0.067 (2)0.0430 (15)0.0067 (15)0.0164 (12)0.0106 (14)
O60.0410 (11)0.116 (2)0.0426 (11)0.0232 (12)0.0172 (9)0.0155 (12)
C50.0432 (15)0.0489 (17)0.0472 (15)−0.0005 (14)0.0173 (12)0.0039 (14)
C70.0463 (15)0.0496 (19)0.0414 (14)−0.0019 (14)0.0173 (12)−0.0020 (14)
C80.0455 (16)0.067 (2)0.0514 (17)0.0022 (15)0.0227 (13)−0.0015 (15)
C1'0.0545 (17)0.0462 (16)0.0460 (15)0.0030 (15)0.0179 (13)−0.0009 (14)
O2'0.0481 (11)0.0631 (14)0.0418 (11)0.0103 (11)0.0062 (9)−0.0075 (10)
C3'0.0558 (17)0.0529 (19)0.0402 (16)−0.0051 (15)0.0131 (14)0.0017 (15)
O3'0.0845 (17)0.088 (2)0.0559 (13)0.0072 (14)0.0055 (12)−0.0251 (15)
C4'0.0491 (18)0.084 (3)0.054 (2)0.0063 (16)0.0039 (15)0.0061 (17)
Geometric parameters (Å, º) top
C1—O21.453 (3)C7—C81.530 (4)
C1—C81.498 (4)C7—H70.9800
C1—C51.518 (4)C8—H8A0.9700
C1—H10.9800C8—H8B0.9700
O2—C31.345 (4)C1'—O2'1.448 (3)
C3—O31.201 (4)C1'—H1A0.9700
C3—C41.490 (4)C1'—H1B0.9700
C4—C51.500 (4)O2'—C3'1.335 (3)
C4—H4A0.9700C3'—O3'1.186 (4)
C4—H4B0.9700C3'—C4'1.481 (4)
O6—C51.415 (3)C4'—H4E0.9600
O6—C71.430 (3)C4'—H4D0.9600
C5—H50.9800C4'—H4C0.9600
C7—C1'1.494 (4)
O2—C1—C8111.3 (2)O6—C7—H7109.3
O2—C1—C5104.6 (2)C1'—C7—H7109.3
C8—C1—C5105.0 (2)C8—C7—H7109.3
O2—C1—H1111.8C1—C8—C7104.3 (2)
C8—C1—H1111.8C1—C8—H8A110.9
C5—C1—H1111.8C7—C8—H8A110.9
C3—O2—C1110.8 (2)C1—C8—H8B110.9
O3—C3—O2120.5 (3)C7—C8—H8B110.9
O3—C3—C4129.1 (3)H8A—C8—H8B108.9
O2—C3—C4110.4 (3)O2'—C1'—C7107.6 (2)
C3—C4—C5104.1 (2)O2'—C1'—H1A110.2
C3—C4—H4A110.9C7—C1'—H1A110.2
C5—C4—H4A110.9O2'—C1'—H1B110.2
C3—C4—H4B110.9C7—C1'—H1B110.2
C5—C4—H4B110.9H1A—C1'—H1B108.5
H4A—C4—H4B109.0C3'—O2'—C1'116.4 (2)
C5—O6—C7111.7 (2)O3'—C3'—O2'122.5 (3)
O6—C5—C4110.4 (3)O3'—C3'—C4'125.4 (3)
O6—C5—C1105.9 (2)O2'—C3'—C4'112.0 (3)
C4—C5—C1104.3 (2)C3'—C4'—H4E109.5
O6—C5—H5111.9C3'—C4'—H4D109.5
C4—C5—H5111.9H4E—C4'—H4D109.5
C1—C5—H5111.9C3'—C4'—H4C109.5
O6—C7—C1'110.1 (2)H4E—C4'—H4C109.5
O6—C7—C8106.5 (2)H4D—C4'—H4C109.5
C1'—C7—C8112.2 (2)
C8—C1—O2—C3130.1 (2)C8—C1—C5—C4−141.0 (3)
C5—C1—O2—C317.2 (3)C5—O6—C7—C1'123.3 (3)
C1—O2—C3—O3177.4 (3)C5—O6—C7—C81.4 (4)
C1—O2—C3—C4−3.3 (3)O2—C1—C8—C7−87.8 (3)
O3—C3—C4—C5167.1 (3)C5—C1—C8—C724.8 (3)
O2—C3—C4—C5−12.1 (3)O6—C7—C8—C1−16.7 (3)
C7—O6—C5—C4126.7 (3)C1'—C7—C8—C1−137.3 (3)
C7—O6—C5—C114.4 (3)O6—C7—C1'—O2'66.4 (3)
C3—C4—C5—O6−91.7 (3)C8—C7—C1'—O2'−175.2 (2)
C3—C4—C5—C121.6 (3)C7—C1'—O2'—C3'177.6 (2)
O2—C1—C5—O692.8 (3)C1'—O2'—C3'—O3'−2.9 (4)
C8—C1—C5—O6−24.5 (3)C1'—O2'—C3'—C4'178.0 (3)
O2—C1—C5—C4−23.7 (3)

Experimental details

Crystal data
Chemical formulaC9H12O5
Mr200.19
Crystal system, space groupMonoclinic, P21
Temperature (K)293
a, b, c (Å)10.015 (5), 4.647 (3), 10.904 (5)
β (°) 109.755 (7)
V (Å3)477.6 (4)
Z2
Radiation typeMo Kα
µ (mm−1)0.12
Crystal size (mm)0.49 × 0.11 × 0.10
Data collection
DiffractometerBruker APEXII CCD
Absorption correctionMulti-scan
(SADABS; Sheldrick, 2008)
Tmin, Tmax0.602, 0.745
No. of measured, independent and
observed [I > 2σ(I)] reflections		2551, 1530, 1313
Rint0.028
(sin θ/λ)max (Å−1)0.596
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.044, 0.097, 1.07
No. of reflections1530
No. of parameters128
No. of restraints1
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å−3)0.14, −0.16

Computer programs: APEX2 (Bruker, 2007), SAINT (Bruker, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008), PLATON (Spek, 2009).

 

Acknowledgements

This work was supported financially by the Xunta de Galicia (No. EXPTE. CN 2012/184). The work of the MS and X-ray divisions of the research support service of the University of Vigo (CACTI) is also gratefully acknowledged. MG thanks the University of Vigo for a PhD fellowship.

References

First citationAgrawal, D., Sriramurthy, V. & Yadav, V. K. (2006). Tetrahedron Lett. 47, 7615–7618.  Web of Science CrossRef CAS Google Scholar
 First citationÁlvarez, C., Pérez, M., Zúñiga, A., Gómez, G. & Fall, Y. (2010). Synthesis, 22, 3883–3890.  Google Scholar
 First citationBanda, G. & Chakravarthy, I. E. (2006). Tetrahedron Asymmetry, 17, 1684–1687.  Web of Science CrossRef CAS Google Scholar
 First citationBruker (2007). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
 First citationHayes, P. Y., Fletcher, M. T., Crow, S., McGrath, M. J., Tu, Y. Q., Zhang, H., Hungerford, N. L., McErlean, C. S. P., Stok, J. E., Moore, C. J., DeVoss, J. J. & Kitching, W. (2003). Quirality, 15, S116–S127.  CAS Google Scholar
 First citationPaddon-Jones, G. C., McErlean, C. S. P., Hayes, P., Moore, C. J., Konig, W. A. & Kitching, W. (2001). J. Org. Chem. 66, 7487–7495.  Web of Science PubMed CAS Google Scholar
 First citationRao, S. T., Westhof, E. & Sundaralingam, M. (1981). Acta Cryst. A37, 421–425.  CrossRef CAS IUCr Journals Web of Science Google Scholar
 First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
 First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 69| Part 5| May 2013| Page o772
https://doi.org/10.1107/S1600536813010313
Follow Acta Cryst. E
Sign up for e-alerts
E-alerts
Follow Acta Cryst. on Twitter
Twitter
Follow us on facebook
Facebook
Sign up for RSS feeds
RSS