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 65| Part 3| March 2009| Pages o610-o611
doi:10.1107/S1600536809006357
ADDENDA AND ERRATA

A correction has been published for this article. To view the correction, click here.

(4S,5R,6R)-Methyl 4-hydr­­oxy-4,5-iso­propyl­­idene­dioxy-4,5,6,7-tetra­hydro-1,2,3-triazolo[1,5-a]pyridine-3-carboxyl­ate

Sarah F. Jenkinson,a* Jennifer R. Fenton,a K. Victoria Booth,a George W. J. Fleeta and David J. Watkinb

aDepartment of Organic Chemistry, Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, England, and bDepartment of Chemical Crystallography, Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, England
*Correspondence e-mail: sarah.jenkinson@chem.ox.ac.uk'

(Received 17 February 2009; accepted 20 February 2009; online 25 February 2009)

X-ray crystallography confirmed the structure of the title triazole, C11H15N3O5, formed from a single-step reaction of a sugar azide with a brominated ylid. The absolute configuration was determined by the use of D-ribose as the starting material. The six-membered ring is in a half-chair conformation. The crystal structure exists as chains of O—H⋯O hydrogen-bonded moleclues running parallel to the b axis.

Related literature

For imino sugars, see: Asano et al. (2000[Asano, N., Nash, R. J., Molyneux, R. J. & Fleet, G. W. J. (2000). Tetrahedron Asymmetry, 11, 1645-1680.]); Watson et al. (2001[Watson, A. A., Fleet, G. W. J., Asano, N., Molyneux, R. J. & Nash, R. J. (2001). Phytochemistry, 56, 265-295.]). For sugar tetra­zoles, see: Brandstetter et al. (1995[Brandstetter, T. W., Davis, B., Hyett, D., Smith, C., Hackett, L., Winchester, B. G. & Fleet, G. W. J. (1995). Tetrahedron Lett. 36, 7511-7514.]); Davis et al. (1995[Davis, B., Brandstetter, T. W., Smith, C., Hackett, L., Winchester, B. G. & Fleet, G. W. J. (1995). Tetrahedron Lett. 36, 7507-7510.]); Ermert et al. (1991[Ermert, P. & Vasella, A. (1991). Helv. Chim. Acta, 74, 2043-2053.]). For sugar triazoles, see: Caravano et al. (2007[Caravano, A., Baillieul, D., Ansiaux, C., Pan, W. D., Kovensky, J., Sinay, P. & Vincent, S. P. (2007). Tetrahedron, 63, 2070-2077.]); Krivopalov & Shkurko (2005[Krivopalov, V. P. & Shkurko, O. P. (2005). Usp. Khim. 74, 369-410.]); Krulle et al. (1997[Krulle, T. M., de la Fuente, C., Pickering, L., Aplin, R. A., Tsitsanou, K. E., Zographos, S. E., Oikonomakos, N. G., Nash, R. J., Griffiths, R. C. & Fleet, G. W. J. (1997). Tetrahedron Asymmetry, 8, 3807-3820.]); Marco-Contelles & Rodriguez-Fernandez (2001[Marco-Contelles, J. & Rodriguez-Fernandez, M. (2001). J. Org. Chem. 66, 3717-3725.], 2002[Marco-Contelles, J. & Rodriguez-Fernandez, M. (2002). Tetrahedron Lett. 41, 381-384.]); Oikonomakos (2002[Oikonomakos, N. G. (2002). Curr. Protein Peptide Sci. 3, 561-586.]); Tatsuta et al. (1996[Tatsuta, K., Ikeda, Y. & Miura, S. (1996). J. Antibiot. 49, 836-838.]). For related literature, see: Görbitz (1999[Görbitz, C. H. (1999). Acta Cryst. B55, 1090-1098.]); Larson (1970[Larson, A. C. (1970). Crystallographic Computing, edited by F. R. Ahmed, S. R. Hall & C. P. Huber, pp. 291-294. Copenhagen: Munksgaard.]).

[Scheme 1]

Experimental

Crystal data

  • C11H15N3O5

  • Mr = 269.26

  • Monoclinic, P 21

  • a = 8.0587 (3) Å

  • b = 7.3797 (3) Å

  • c = 10.9785 (5) Å

  • β = 96.2740 (18)°

  • V = 648.99 (5) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 0.11 mm−1

  • T = 150 K

  • 0.60 × 0.15 × 0.03 mm
Data collection

  • Nonius KappaCCD diffractometer

  • Absorption correction: multi-scan (DENZO/SCALEPACK; Otwinowski & Minor, 1997[Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307-326. New York: Academic Press.]) Tmin = 0.82, Tmax = 1.00 (expected range = 0.817–0.997)

  • 9525 measured reflections

  • 1595 independent reflections

  • 1219 reflections with I > 2σ(I)

  • Rint = 0.059
Refinement

  • R[F2 > 2σ(F2)] = 0.037

  • wR(F2) = 0.082

  • S = 0.96

  • 1595 reflections

  • 173 parameters

  • 1 restraint

  • H-atom parameters constrained

  • Δρmax = 0.30 e Å−3

  • Δρmin = −0.31 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A D⋯A D—H⋯A
O19—H191⋯O4i 0.84 1.96 2.782 (4) 163
Symmetry code: (i) x, y-1, z.

Data collection: COLLECT (Nonius, 2001[Nonius (2001). COLLECT. Nonius BV, Delft, The Netherlands.]).; cell refinement: DENZO/SCALEPACK (Otwinowski & Minor, 1997[Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307-326. New York: Academic Press.]); data reduction: DENZO/SCALEPACK; program(s) used to solve structure: SIR92 (Altomare et al., 1994[Altomare, A., Cascarano, G., Giacovazzo, C., Guagliardi, A., Burla, M. C., Polidori, G. & Camalli, M. (1994). J. Appl. Cryst. 27, 435.]); program(s) used to refine structure: CRYSTALS (Betteridge et al., 2003[Betteridge, P. W., Carruthers, J. R., Cooper, R. I., Prout, K. & Watkin, D. J. (2003). J. Appl. Cryst. 36, 1487.]); molecular graphics: CAMERON (Watkin et al., 1996[Watkin, D. J., Prout, C. K. & Pearce, L. J. (1996). CAMERON. Chemical Crystallography Laboratory, Oxford, England.]); software used to prepare material for publication: CRYSTALS.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809006357/lh2778sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809006357/lh2778Isup2.hkl

checkCIF report


Comment top

Sugars with the ring oxygen replaced by nitrogen comprise a large family of both natural products and synthetic analogues which inhibit sugar metabolizing enzymes (Asano et al., 2000; Watson et al., 2001), including compounds which incorporate a tetrazole (Ermert et al., 1991; Davis et al., 1995; Brandstetter et al., 1995) or triazole (Tatsuta et al., 1996; Marco-Contelles & Rodriguez-Fernandez, 2002; Caravano et al., 2007; Krivpalov & Shkurko, 2007) fused to the pyranose ring. Some sugar triazoles have potential as glycogen phosphorylase inhibitors (Oikonomakos, 2002). Usually the synthesis of pyranose triazoles requires many steps (Marco-Contelles & Rodriguez-Fernandez, 2001; Krulle et al., 1997).

A single step synthesis (see Fig. 1) has been developed in which an azidolactol 1 was reacted with Ph3P=CBrCOOMe; the open chain form 2 underwent a Wittig reaction to give 3 which was followed by an intramolecular 1,3-dipolar addition of the azide to the alkene to afford 4. Subsequent elimination of HBr gave the target compound 5. The structure of the product 5, including the relative configuration of the three chiral centers was confirmed by X-ray crystallographic analysis. The absolute configuration was determined by the use of D-ribose as the starting material for the preparation of azidolactol 1.

The crystal structure of 5 exisits as chains of O—H···O hydrogen bonded moleclues lying parallel to the b-axis. Only classical hydrogen bonding has been considered. The 6-membered ring exists in a half-chair conformation.

Related literature top

For imino sugars, see: Asano et al. (2000); Watson et al. (2001). For sugar tetrazoles, see: Brandstetter et al. (1995); Davis et al. (1995); Ermert et al. (1991). For sugar triazoles, see: Caravano et al. (2007); Krivopalov & Shkurko (2005); Krulle et al. (1997); Marco-Contelles & Rodriguez-Fernandez (2001, 2002); Oikonomakos (2002); Tatsuta et al. (1996).

For related literature, see: Görbitz (1999); Larson (1970).

Experimental top

The title compound was recrystallized by vapour diffusion from a mixture of ether and cyclohexane: m.p. 413–415 K; [α]D21 -140.7 (c, 1.01 in CHCl3).

Refinement top

In the absence of significant anomalous scattering, Friedel pairs were merged and the absolute configuration was assigned from the starting material.

The relatively large ratio of minimum to maximum corrections applied in the multiscan process (1:1.21) reflect changes in the illuminated volume of the crystal. Changes in illuminated volume were kept to a minimum, and were taken into account (Görbitz, 1999) by the multi-scan inter-frame scaling (DENZO/SCALEPACK, Otwinowski & Minor, 1997).

The H atoms were all located in a difference map, but those attached to carbon atoms were repositioned geometrically. The H atoms were initially refined with soft restraints on the bond lengths and angles to regularize their geometry (C—H in the range 0.93–0.98, O—H = 0.82 Å) and Uiso(H) (in the range 1.2–1.5 times Ueq of the parent atom), after which the positions were refined with riding constraints.

Computing details top

Data collection: COLLECT (Nonius, 2001).; cell refinement: DENZO/SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO/SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: CRYSTALS (Betteridge et al., 2003); molecular graphics: CAMERON (Watkin et al., 1996); software used to prepare material for publication: CRYSTALS (Betteridge et al., 2003).

Figures top
[Figure 1] Fig. 1. Synthetic Scheme.
[Figure 2] Fig. 2. The molecluar structure showing the crystallographic labelling scheme and displacement ellipsoids drawn at the 50% probability level. H atoms are shown as spheres of arbitary radius.
[Figure 3] Fig. 3. Part of the crystal structure of the title compound projected along the a-axis. Hydrogen bonds are indicated by dotted lines.
(4S,5R,6R)-Methyl 4-hydroxy-4,5-isopropylidenedioxy-4,5,6,7-tetrahydro-1,2,3- triazolo[1,5-a]pyridine-3-carboxylate top
Crystal data top
C11H15N3O5F(000) = 284
Mr = 269.26Dx = 1.378 Mg m−3
Monoclinic, P21Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ybCell parameters from 1565 reflections
a = 8.0587 (3) Åθ = 5–27°
b = 7.3797 (3) ŵ = 0.11 mm−1
c = 10.9785 (5) ÅT = 150 K
β = 96.2740 (18)°Plate, colourless
V = 648.99 (5) Å30.60 × 0.15 × 0.03 mm
Z = 2
Data collection top
Nonius KappaCCD
diffractometer		1219 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.059
ω scansθmax = 27.5°, θmin = 5.2°
Absorption correction: multi-scan
(DENZO/SCALEPACK; Otwinowski & Minor, 1997)		h = −10→10
Tmin = 0.82, Tmax = 1.00k = −9→9
9525 measured reflectionsl = −14→14
1595 independent reflections
Refinement top
Refinement on F2Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: fullH-atom parameters constrained
R[F2 > 2σ(F2)] = 0.037 Method = Modified Sheldrick w = 1/[σ2(F2) + (0.04P)2 + 0.06P],
where P = [max(Fo2,0) + 2Fc2]/3
wR(F2) = 0.082(Δ/σ)max = 0.000083
S = 0.97Δρmax = 0.30 e Å−3
1595 reflectionsΔρmin = −0.31 e Å−3
173 parametersExtinction correction: Larson (1970), Equation 22
1 restraintExtinction coefficient: 120 (30)
Primary atom site location: structure-invariant direct methods
Crystal data top
C11H15N3O5V = 648.99 (5) Å3
Mr = 269.26Z = 2
Monoclinic, P21Mo Kα radiation
a = 8.0587 (3) ŵ = 0.11 mm−1
b = 7.3797 (3) ÅT = 150 K
c = 10.9785 (5) Å0.60 × 0.15 × 0.03 mm
β = 96.2740 (18)°
Data collection top
Nonius KappaCCD
diffractometer		1595 independent reflections
Absorption correction: multi-scan
(DENZO/SCALEPACK; Otwinowski & Minor, 1997)		1219 reflections with I > 2σ(I)
Tmin = 0.82, Tmax = 1.00Rint = 0.059
9525 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0371 restraint
wR(F2) = 0.082H-atom parameters constrained
S = 0.97Δρmax = 0.30 e Å−3
1595 reflectionsΔρmin = −0.31 e Å−3
173 parameters
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.2044 (2)0.3385 (2)0.12370 (17)0.0348
C20.3680 (3)0.2921 (3)0.0939 (2)0.0259
C30.4700 (3)0.4559 (3)0.14365 (19)0.0263
O40.3535 (2)0.6018 (2)0.12971 (16)0.0369
C50.1853 (3)0.5296 (3)0.1071 (3)0.0371
C60.1173 (3)0.5757 (4)−0.0230 (3)0.0481
C70.0820 (4)0.5983 (5)0.2022 (3)0.0711
C80.5404 (3)0.4306 (3)0.27502 (19)0.0274
N90.5115 (2)0.2809 (3)0.33823 (15)0.0314
N100.5960 (3)0.2829 (4)0.45255 (16)0.0404
N110.6780 (2)0.4367 (3)0.46271 (17)0.0393
C120.6470 (3)0.5312 (3)0.35555 (19)0.0301
C130.7152 (3)0.7105 (4)0.3339 (2)0.0347
O140.6759 (2)0.7985 (3)0.24224 (16)0.0410
O150.8253 (2)0.7650 (3)0.42672 (17)0.0493
C160.8993 (4)0.9424 (5)0.4125 (3)0.0619
C170.4111 (3)0.1253 (4)0.2922 (2)0.0340
C180.4225 (3)0.1151 (3)0.1552 (2)0.0282
O190.3191 (2)−0.0250 (2)0.10143 (15)0.0345
H210.37160.28230.00300.0326*
H310.56280.48000.09230.0335*
H620.12130.7081−0.03060.0684*
H610.00130.5339−0.03900.0679*
H630.18730.5166−0.07910.0683*
H720.07600.72960.19460.1122*
H71−0.02940.54660.18980.1121*
H730.13670.56580.28260.1119*
H1630.99990.95060.47000.0913*
H1620.92840.95530.32940.0911*
H1610.81931.03530.43040.0913*
H1720.29300.14230.30740.0432*
H1710.45920.01510.33270.0435*
H1810.54170.09150.14250.0336*
H1910.3489−0.13270.11660.0521*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0270 (8)0.0198 (9)0.0582 (11)0.0004 (7)0.0067 (7)0.0020 (7)
C20.0241 (11)0.0212 (11)0.0325 (11)0.0008 (10)0.0032 (8)−0.0010 (11)
C30.0298 (11)0.0224 (12)0.0259 (11)0.0021 (10)−0.0007 (9)0.0011 (10)
O40.0340 (9)0.0205 (9)0.0524 (11)0.0020 (8)−0.0125 (7)−0.0004 (8)
C50.0267 (12)0.0178 (12)0.0658 (17)0.0013 (10)0.0007 (11)−0.0001 (12)
C60.0357 (13)0.0268 (14)0.0762 (19)−0.0026 (12)−0.0191 (13)0.0064 (14)
C70.075 (2)0.041 (2)0.105 (3)0.0097 (18)0.0425 (19)−0.0053 (19)
C80.0270 (11)0.0247 (12)0.0305 (11)0.0084 (11)0.0040 (9)−0.0028 (11)
N90.0372 (10)0.0314 (11)0.0256 (9)0.0035 (10)0.0040 (8)0.0024 (9)
N100.0491 (12)0.0475 (14)0.0241 (9)0.0073 (12)0.0023 (8)0.0009 (11)
N110.0427 (11)0.0465 (14)0.0279 (10)0.0110 (12)−0.0003 (8)−0.0067 (11)
C120.0294 (11)0.0315 (14)0.0283 (12)0.0091 (10)−0.0011 (9)−0.0061 (11)
C130.0262 (11)0.0346 (14)0.0413 (14)0.0068 (11)−0.0055 (10)−0.0129 (12)
O140.0382 (9)0.0298 (10)0.0524 (11)0.0004 (9)−0.0062 (8)−0.0029 (10)
O150.0406 (10)0.0451 (13)0.0576 (11)0.0030 (9)−0.0157 (8)−0.0195 (10)
C160.0454 (15)0.0440 (19)0.091 (2)−0.0055 (16)−0.0167 (14)−0.0262 (18)
C170.0404 (13)0.0262 (13)0.0366 (13)0.0005 (11)0.0099 (10)0.0045 (11)
C180.0313 (11)0.0196 (12)0.0335 (12)0.0020 (10)0.0030 (9)0.0005 (10)
O190.0413 (9)0.0137 (8)0.0481 (10)0.0003 (7)0.0036 (7)−0.0011 (7)
Geometric parameters (Å, º) top
O1—C21.434 (3)C8—C121.380 (3)
O1—C51.429 (3)N9—N101.361 (3)
C2—C31.529 (3)N9—C171.463 (3)
C2—C181.512 (3)N10—N111.312 (3)
C2—H211.004N11—C121.367 (3)
C3—O41.426 (3)C12—C131.462 (4)
C3—C81.503 (3)C13—O141.211 (3)
C3—H311.000C13—O151.338 (3)
O4—C51.452 (3)O15—C161.454 (4)
C5—C61.512 (4)C16—H1630.973
C5—C71.494 (4)C16—H1620.971
C6—H620.981C16—H1610.976
C6—H610.982C17—C181.519 (3)
C6—H630.982C17—H1720.992
C7—H720.973C17—H1710.986
C7—H710.971C18—O191.416 (3)
C7—H730.973C18—H1811.001
C8—N91.339 (3)O19—H1910.842
C2—O1—C5107.18 (19)C3—C8—C12133.8 (2)
O1—C2—C3101.66 (18)N9—C8—C12104.07 (19)
O1—C2—C18109.52 (18)C8—N9—N10111.8 (2)
C3—C2—C18113.92 (17)C8—N9—C17126.16 (18)
O1—C2—H21111.8N10—N9—C17122.0 (2)
C3—C2—H21109.8N9—N10—N11106.53 (19)
C18—C2—H21110.0N10—N11—C12108.96 (19)
C2—C3—O4103.68 (16)C8—C12—N11108.7 (2)
C2—C3—C8112.1 (2)C8—C12—C13127.0 (2)
O4—C3—C8111.83 (18)N11—C12—C13124.4 (2)
C2—C3—H31110.2C12—C13—O14123.5 (2)
O4—C3—H31109.2C12—C13—O15112.2 (2)
C8—C3—H31109.6O14—C13—O15124.3 (3)
C3—O4—C5109.44 (17)C13—O15—C16115.8 (2)
O4—C5—O1104.75 (19)O15—C16—H163108.0
O4—C5—C6108.3 (2)O15—C16—H162109.4
O1—C5—C6111.5 (2)H163—C16—H162109.5
O4—C5—C7109.7 (2)O15—C16—H161108.8
O1—C5—C7107.8 (2)H163—C16—H161110.4
C6—C5—C7114.3 (2)H162—C16—H161110.6
C5—C6—H62107.0N9—C17—C18106.86 (19)
C5—C6—H61109.7N9—C17—H172110.3
H62—C6—H61109.7C18—C17—H172109.6
C5—C6—H63108.6N9—C17—H171108.5
H62—C6—H63111.3C18—C17—H171110.0
H61—C6—H63110.4H172—C17—H171111.4
C5—C7—H72107.7C17—C18—C2110.60 (19)
C5—C7—H71110.2C17—C18—O19110.65 (19)
H72—C7—H71110.0C2—C18—O19108.43 (17)
C5—C7—H73108.6C17—C18—H181108.0
H72—C7—H73109.7C2—C18—H181108.9
H71—C7—H73110.5O19—C18—H181110.2
C3—C8—N9122.1 (2)C18—O19—H191117.7
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H31···O19i1.002.423.339 (4)152
C16—H161···N10ii0.982.593.567 (4)174
O19—H191···O4iii0.841.962.782 (4)163
Symmetry codes: (i) −x+1, y+1/2, −z; (ii) x, y+1, z; (iii) x, y−1, z.

Experimental details

Crystal data
Chemical formulaC11H15N3O5
Mr269.26
Crystal system, space groupMonoclinic, P21
Temperature (K)150
a, b, c (Å)8.0587 (3), 7.3797 (3), 10.9785 (5)
β (°) 96.2740 (18)
V (Å3)648.99 (5)
Z2
Radiation typeMo Kα
µ (mm−1)0.11
Crystal size (mm)0.60 × 0.15 × 0.03
Data collection
DiffractometerNonius KappaCCD
diffractometer
Absorption correctionMulti-scan
(DENZO/SCALEPACK; Otwinowski & Minor, 1997)
Tmin, Tmax0.82, 1.00
No. of measured, independent and
observed [I > 2σ(I)] reflections		9525, 1595, 1219
Rint0.059
(sin θ/λ)max (Å−1)0.650
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.037, 0.082, 0.97
No. of reflections1595
No. of parameters173
No. of restraints1
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å−3)0.30, −0.31

Computer programs: COLLECT (Nonius, 2001)., DENZO/SCALEPACK (Otwinowski & Minor, 1997), SIR92 (Altomare et al., 1994), CRYSTALS (Betteridge et al., 2003), CAMERON (Watkin et al., 1996).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O19—H191···O4i0.841.962.782 (4)163
Symmetry code: (i) x, y−1, z.
 

Acknowledgements

The authors wish to thank the Oxford University Crystallography Service for use of the instruments.

References

First citationAltomare, A., Cascarano, G., Giacovazzo, C., Guagliardi, A., Burla, M. C., Polidori, G. & Camalli, M. (1994). J. Appl. Cryst. 27, 435.  CrossRef Web of Science IUCr Journals Google Scholar
 First citationAsano, N., Nash, R. J., Molyneux, R. J. & Fleet, G. W. J. (2000). Tetrahedron Asymmetry, 11, 1645–1680.  Web of Science CrossRef CAS Google Scholar
 First citationBetteridge, P. W., Carruthers, J. R., Cooper, R. I., Prout, K. & Watkin, D. J. (2003). J. Appl. Cryst. 36, 1487.  Web of Science CrossRef IUCr Journals Google Scholar
 First citationBrandstetter, T. W., Davis, B., Hyett, D., Smith, C., Hackett, L., Winchester, B. G. & Fleet, G. W. J. (1995). Tetrahedron Lett. 36, 7511–7514.  CrossRef CAS Web of Science Google Scholar
 First citationCaravano, A., Baillieul, D., Ansiaux, C., Pan, W. D., Kovensky, J., Sinay, P. & Vincent, S. P. (2007). Tetrahedron, 63, 2070–2077.  Web of Science CrossRef CAS Google Scholar
 First citationDavis, B., Brandstetter, T. W., Smith, C., Hackett, L., Winchester, B. G. & Fleet, G. W. J. (1995). Tetrahedron Lett. 36, 7507–7510.  CrossRef CAS Web of Science Google Scholar
 First citationErmert, P. & Vasella, A. (1991). Helv. Chim. Acta, 74, 2043–2053.  CSD CrossRef CAS Web of Science Google Scholar
 First citationGörbitz, C. H. (1999). Acta Cryst. B55, 1090–1098.  Web of Science CSD CrossRef IUCr Journals Google Scholar
 First citationKrivopalov, V. P. & Shkurko, O. P. (2005). Usp. Khim. 74, 369–410.  CrossRef Google Scholar
 First citationKrulle, T. M., de la Fuente, C., Pickering, L., Aplin, R. A., Tsitsanou, K. E., Zographos, S. E., Oikonomakos, N. G., Nash, R. J., Griffiths, R. C. & Fleet, G. W. J. (1997). Tetrahedron Asymmetry, 8, 3807–3820.  CrossRef CAS Web of Science Google Scholar
 First citationLarson, A. C. (1970). Crystallographic Computing, edited by F. R. Ahmed, S. R. Hall & C. P. Huber, pp. 291–294. Copenhagen: Munksgaard.  Google Scholar
 First citationMarco-Contelles, J. & Rodriguez-Fernandez, M. (2001). J. Org. Chem. 66, 3717–3725.  Web of Science CrossRef PubMed CAS Google Scholar
 First citationMarco-Contelles, J. & Rodriguez-Fernandez, M. (2002). Tetrahedron Lett. 41, 381–384.  Web of Science CrossRef Google Scholar
 First citationNonius (2001). COLLECT. Nonius BV, Delft, The Netherlands.  Google Scholar
 First citationOikonomakos, N. G. (2002). Curr. Protein Peptide Sci. 3, 561–586.  Web of Science CrossRef CAS Google Scholar
 First citationOtwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307–326. New York: Academic Press.  Google Scholar
 First citationTatsuta, K., Ikeda, Y. & Miura, S. (1996). J. Antibiot. 49, 836–838.  CrossRef CAS PubMed Web of Science Google Scholar
 First citationWatkin, D. J., Prout, C. K. & Pearce, L. J. (1996). CAMERON. Chemical Crystallography Laboratory, Oxford, England.  Google Scholar
 First citationWatson, A. A., Fleet, G. W. J., Asano, N., Molyneux, R. J. & Nash, R. J. (2001). Phytochemistry, 56, 265–295.  Web of Science CrossRef PubMed CAS 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 65| Part 3| March 2009| Pages o610-o611
doi:10.1107/S1600536809006357
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