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

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1,2:3,4-Di-O-iso­propyl­­idene-β-D-psico­furan­ose

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aDepartment of Chemical Crystallography, Chemical Research Laboratory, Oxford University, Mansfield Road, Oxford OX1 3TA, England, bDepartment of Organic Chemistry, Chemical Research Laboratory, Oxford University, Mansfield Road, Oxford OX1 3TA, England, cRare Sugar Research Centre, Kagawa University, Mikicho, Kagawa 761-0795 Japan, and dGlycobiology Institute, Department of Biochemistry, Oxford University, South Parks Road, Oxford OX1 3QU, England
*Correspondence e-mail: david.watkin@chem.ox.ac.uk

(Received 5 August 2005; accepted 10 August 2005; online 17 August 2005)

The crystal structure of the title diacetone psicose, C12H20O6, establishes the stereochemistry of the anomeric spiro­acetal 1,2:3,4-di-O-isopropyl­idene-β-D-psicofuran­ose. The structure consists of columns of mol­ecules linked by hydrogen bonds into chains [O⋯O 2.962 (2) Å] lying parallel to the a axis.

Comment

Izumoring, a combination of enzymic epimerizations of ketohexoses combined with microbial oxidation–reduction procedures, can provide access to any hexose in substantial quantity via environmentally friendly procedures (Granstrom et al., 2004[Granstrom, T. B., Takata, G., Tokuda, M. & Izumori, K. (2004). J. Biosci. Bioeng. 97, 89-94.]; Izumori, 2002[Izumori, K. (2002). Naturwissenschaften, 89, 120-124.]). The rare sugar D-psicose, (1), is now available for the first time in multi-kilogram quantities from the equilibration of D-fructose by D-tagatose 3-epimerase (Takeshita et al., 2000[Takeshita, K., Suga, A., Takada, G. & Izumori, K. (2000). J. Biosci. Bioeng. 90, 453-455.]; Itoh & Izumori, 1996[Itoh, H. & Izumori, K. (1996). J. Ferment. Bioeng. 81, 351-353.]; Itoh et al., 1995[Itoh, H., Sato, I. & Izumori, K. (1995). J. Ferment. Bioeng. 80, 101-103.]). Although the main purpose of large-scale production of rare sugars such as D-psicose is for their use in food technology (Sun et al., 2004[Sun, Y., Hayakawa, S. & Izumori, K. (2004). J. Agric. Food. Chem. 52, 1293-1299.], 2005[Sun, Y., Hayakawa, S., Puangmanee, S. & Izumori, K. (2005). Food Chem. In the press (doi 10.1016/j.foodchem. 2005.01.033).]), such studies will significantly increase the number of sugar chirons (Lichtenthaler & Peters, 2004[Lichtenthaler, F. W. & Peters, S. (2004). C. R. Chim. 7, 65-90.]; Soengas, Izumori et al., 2005[Soengas, R., Izumori, K., Simone, M. I., Watkin, D. J., Skytte, U. P., Soetaert, W. & Fleet, G. W. J. (2005). Tetrahedron Lett. 46, 5755-5759.]).

[Scheme 1]

Crystalline diacetonides of carbohydrates are among the most common chiral building blocks in organic synthesis (Bols, 1996[Bols, M. (1996). Carbohydrate Building Blocks. New York: John Wiley & Sons, Inc.]). The first report of the reaction of psicose with acetone was the formation of a furan­ose diacetonide from L-psicose (Steiger & Reichstein, 1935[Steiger, M. & Reichstein, T. (1935). Helv. Chim. Acta, 18, 790-799.]); the reaction of D-psicose, (1), with acetone gave an enantiomeric diacetonide, (2) (Steiger & Reichstein, 1936[Steiger, M. & Reichstein, T. (1936). Helv. Chim. Acta, 19, 184-189.]), with no indication of the chemistry at the anomeric position. All other syntheses of the furan­ose diacetonide, (2), have been multi-step procedures starting from a pyran­ose diacetonide of fructose. The original procedure for the preparation of (2) from D-fructose (James et al., 1967[James, K. J., Tatchell, A. R. & Ray, P. R. (1967). J. Chem. Soc. C, pp. 2681-2686.]) has been significantly improved (James et al., 1967[James, K. J., Tatchell, A. R. & Ray, P. R. (1967). J. Chem. Soc. C, pp. 2681-2686.]; Cree & Perlin, 1968[Cree, G. M. & Perlin, A. S. (1968). Can. J. Biochem. 46, 765-770.]; Tipson et al., 1971[Tipson, S., Brady, R. & West, B. (1971). Carbohydr. Res. 16, 383-393.]). The diacetonide, (2), has been used as a starting material for the synthesis of nucleosides (Prisbe et al., 1976[Prisbe, E. J., Smejkal, J., Verdehyden, J. P. H. & Moffat, J. G. (1976). J. Org. Chem. 41, 1836-1846.]) and imino sugars (Joseph et al., 2002[Joseph, C. C., Regeling, H., Zwanenburg, B. & Chittenden, G. J. F. (2002). Carbohydr. Res. 337, 1083-1087.]). There is no report in any of the numerous previous papers of any attempt to determine the anomeric configuration of the spiro-acetal functionality in (2). In recent studies, it was found that treatment of psicose (1) with acetone in the presence of acid afforded the easily crystallized diacetone psicose, (2) (Soengas, Wormald et al., 2005[Soengas, R., Wormald, M. R., Dwek, R. A., Izumori, K., Watkin, D. J., Skytte, U. P. & Fleet, G. W. J. (2005). In preparation.]), in good yield. The present report of the crystal structure of (2) unequivocally establishes the anomeric configuration of the diacetonide, (3), as the β-form (Fig. 1[link]).

The structure of (2) consists of columns of mol­ecules linked by hydrogen bonds into chains [O⋯O = 2.962 (2) Å] lying parallel to the a axis (Fig. 2[link]). Contacts between the chains are determined largely by the methyl groups.

[Figure 1]
Figure 1
The mol­ecule of the title compound, with displacement ellipsoids drawn at the 50% probability level. H atoms are shown as spheres of arbitary radii.
[Figure 2]
Figure 2
A projection along the c axis of the crystal structure of the title compound, showing chains of mol­ecules lying parallel to the a axis. Hydrogen bonds are shown as dotted lines.

Experimental

The title material, (2) (Soengas, Wormald et al., 2005[Soengas, R., Wormald, M. R., Dwek, R. A., Izumori, K., Watkin, D. J., Skytte, U. P. & Fleet, G. W. J. (2005). In preparation.]), was crystallized from 333–353 K petroleum ether.

Crystal data
  • C12H20O6

  • Mr = 260.29

  • Orthorhombic, C 2221

  • a = 7.5915 (2) Å

  • b = 20.1407 (6) Å

  • c = 17.5607 (6) Å

  • V = 2685.00 (14) Å3

  • Z = 8

  • Dx = 1.288 Mg m−3

  • Mo Kα radiation

  • Cell parameters from 1674 reflections

  • θ = 5–27°

  • μ = 0.10 mm−1

  • T = 190 K

  • Prism, colourless

  • 0.45 × 0.15 × 0.15 mm

Data collection
  • Nonius KappaCCD area-detector diffractometer

  • ω scans

  • 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 = 0.86, Tmax = 0.98

  • 9365 measured reflections

  • 1721 independent reflections

  • 1721 reflections with I > 3σ(I)

  • Rint = 0.030

  • θmax = 27.5°

  • h = −9 → 9

  • k = −25 → 25

  • l = −22 → 22

Refinement
  • Refinement on F2

  • R[F2 > 2σ(F2)] = 0.041

  • wR(F2) = 0.078

  • S = 0.94

  • 1721 reflections

  • 163 parameters

  • H-atom parameters constrained

  • w = 1/[σ2(F2) + (0.04P)2 + 0.76P] where P = (max(Fo2,0) + 2Fc2)/3

  • (Δ/σ)max < 0.001

  • Δρmax = 0.18 e Å−3

  • Δρmin = −0.17 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)[link]

D—H⋯A D—H H⋯A DA D—H⋯A
O7—H1⋯O8i 0.84 2.19 2.962 (2) 152
Symmetry code: (i) [x+{\script{1\over 2}}, -y+{\script{3\over 2}}, -z+1].

Because the data were collected with molybdenum radiation, there were no measurable anomalous differences, as a consequence of which it was admissible to merge Friedel pairs of reflections. The H atoms were all located in a difference map, but those attached to C atoms were repositioned geometrically. The H atoms were initially refined with soft restraints on the bond lengths and angles in order to regularize their geometry [C—H distances in the range 0.93–98 Å and O—H = 0.82 Å, and Uiso(H) in the range 1.2–1.5Ueq of the adjacent atom], after which they were refined with riding constraints.

Data collection: COLLECT. (Nonius, 1997-2001[Nonius (1997-2001). 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, C. 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, University of Oxford, England.]); software used to prepare material for publication: CRYSTALS.

Supporting information


Computing details top

Data collection: COLLECT. (Nonius, 1997-2001).; cell refinement: DENZO/SCALEPACK; 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.

1,2:3,4-Di-O-isopropylidene-β-D-psicofuranose top
Crystal data top
C12H20O6F(000) = 1120
Mr = 260.29Dx = 1.288 Mg m3
Orthorhombic, C2221Mo Kα radiation, λ = 0.71073 Å
Hall symbol: C 2c 2Cell parameters from 1674 reflections
a = 7.5915 (2) Åθ = 5–27°
b = 20.1407 (6) ŵ = 0.10 mm1
c = 17.5607 (6) ÅT = 190 K
V = 2685.00 (14) Å3Prism, colourless
Z = 80.45 × 0.15 × 0.15 mm
Data collection top
Nonius KappaCCD area-detector
diffractometer
1721 reflections with I > 3σ(I)
Graphite monochromatorRint = 0.030
ω scansθmax = 27.5°, θmin = 5.3°
Absorption correction: multi-scan
(DENZO/SCALEPACK; Otwinowski & Minor, 1997)
h = 99
Tmin = 0.86, Tmax = 0.98k = 2525
9365 measured reflectionsl = 2222
1721 independent reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.041H-atom parameters constrained
wR(F2) = 0.078 w = 1/[σ2(F2) + (0.04P)2 + 0.76P]
where P = (max(Fo2,0) + 2Fc2)/3
S = 0.94(Δ/σ)max = 0.000268
1721 reflectionsΔρmax = 0.18 e Å3
163 parametersΔρmin = 0.17 e Å3
0 restraints
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
C10.9879 (2)0.86900 (8)0.45535 (9)0.0289
C20.8171 (2)0.89925 (9)0.48595 (11)0.0326
C30.6934 (2)0.84018 (8)0.49965 (10)0.0306
C40.7929 (2)0.78036 (8)0.47003 (10)0.0275
O50.97603 (15)0.79999 (5)0.47083 (6)0.0275
C60.7334 (2)0.75971 (9)0.39077 (10)0.0337
O70.8303 (2)0.70508 (7)0.36253 (8)0.0469
O80.68145 (18)0.83598 (6)0.58096 (7)0.0376
C90.7244 (3)0.89956 (10)0.61173 (12)0.0420
O100.84906 (18)0.92652 (7)0.55968 (8)0.0444
C110.5620 (3)0.94323 (12)0.61528 (16)0.0624
C120.8129 (5)0.88883 (13)0.68779 (13)0.0715
O131.00256 (16)0.88126 (6)0.37606 (7)0.0345
C141.1874 (2)0.88150 (11)0.35570 (11)0.0394
O151.28119 (17)0.88358 (7)0.42634 (8)0.0435
C161.1595 (2)0.89624 (9)0.48621 (11)0.0339
C171.2359 (3)0.81797 (12)0.31560 (12)0.0549
C181.2212 (3)0.94316 (13)0.30907 (15)0.0683
H210.76940.93280.45020.0469*
H310.57610.84680.47640.0423*
H410.78000.74210.50530.0377*
H610.60700.74650.39410.0480*
H620.74790.79870.35690.0483*
H1110.59820.98670.63470.1113*
H1120.51470.94730.56450.1113*
H1130.47660.92170.64850.1119*
H1210.84090.93250.70880.1258*
H1220.73260.86570.72120.1269*
H1230.91850.86210.67960.1264*
H1611.14890.94420.49440.0481*
H1621.19840.87200.53330.0472*
H1711.36060.82080.30270.0983*
H1721.16770.81520.26790.0984*
H1731.20980.78030.34890.0988*
H1811.34470.94620.29850.1209*
H1821.15720.93980.26210.1211*
H1831.18450.98190.33800.1212*
H10.93520.70800.37750.0833*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0298 (8)0.0252 (8)0.0317 (9)0.0004 (7)0.0024 (7)0.0033 (7)
C20.0307 (9)0.0282 (9)0.0390 (10)0.0043 (8)0.0006 (8)0.0047 (8)
C30.0288 (8)0.0322 (9)0.0307 (8)0.0018 (8)0.0027 (8)0.0006 (7)
C40.0269 (8)0.0287 (8)0.0270 (8)0.0032 (7)0.0016 (7)0.0003 (7)
O50.0266 (6)0.0228 (5)0.0331 (6)0.0004 (5)0.0027 (5)0.0015 (5)
C60.0309 (9)0.0389 (10)0.0314 (9)0.0032 (8)0.0027 (7)0.0031 (8)
O70.0438 (8)0.0537 (8)0.0432 (8)0.0008 (7)0.0022 (7)0.0204 (6)
O80.0509 (8)0.0301 (6)0.0317 (6)0.0030 (6)0.0066 (6)0.0054 (5)
C90.0460 (11)0.0347 (10)0.0453 (11)0.0019 (9)0.0049 (9)0.0112 (9)
O100.0441 (8)0.0368 (7)0.0524 (8)0.0069 (6)0.0084 (7)0.0168 (6)
C110.0559 (14)0.0432 (12)0.0881 (19)0.0039 (11)0.0269 (13)0.0142 (12)
C120.099 (2)0.0689 (15)0.0468 (13)0.0017 (18)0.0115 (15)0.0215 (12)
O130.0267 (6)0.0445 (7)0.0323 (6)0.0030 (7)0.0031 (5)0.0103 (5)
C140.0252 (9)0.0569 (12)0.0360 (10)0.0085 (9)0.0049 (8)0.0145 (9)
O150.0268 (6)0.0635 (9)0.0400 (7)0.0028 (6)0.0055 (6)0.0040 (7)
C160.0345 (9)0.0272 (9)0.0399 (11)0.0008 (8)0.0039 (8)0.0005 (8)
C170.0400 (11)0.0813 (16)0.0433 (12)0.0001 (12)0.0055 (9)0.0016 (11)
C180.0451 (13)0.0847 (18)0.0752 (17)0.0270 (13)0.0131 (12)0.0452 (15)
Geometric parameters (Å, º) top
C1—C21.530 (2)C9—C121.511 (3)
C1—O51.419 (2)C11—H1110.980
C1—O131.418 (2)C11—H1120.965
C1—C161.514 (2)C11—H1130.973
C2—C31.535 (2)C12—H1210.977
C2—O101.427 (2)C12—H1220.966
C2—H210.991C12—H1230.977
C3—C41.514 (2)O13—C141.448 (2)
C3—O81.433 (2)C14—O151.431 (2)
C3—H310.989C14—C171.506 (3)
C4—O51.446 (2)C14—C181.510 (3)
C4—C61.521 (2)O15—C161.423 (2)
C4—H410.993C16—H1610.979
C6—O71.413 (2)C16—H1621.005
C6—H610.997C17—H1710.975
C6—H620.992C17—H1720.986
O7—H10.841C17—H1730.978
O8—C91.428 (2)C18—H1810.958
C9—O101.424 (2)C18—H1820.960
C9—C111.516 (3)C18—H1830.973
C2—C1—O5105.60 (14)C2—O10—C9108.83 (14)
C2—C1—O13110.00 (14)C9—C11—H111107.8
O5—C1—O13111.31 (13)C9—C11—H112108.3
C2—C1—C16117.33 (13)H111—C11—H112110.5
O5—C1—C16109.94 (15)C9—C11—H113108.0
O13—C1—C16102.76 (14)H111—C11—H113112.1
C1—C2—C3105.37 (14)H112—C11—H113110.1
C1—C2—O10109.14 (15)C9—C12—H121107.6
C3—C2—O10105.08 (14)C9—C12—H122109.0
C1—C2—H21111.1H121—C12—H122109.9
C3—C2—H21113.8C9—C12—H123108.3
O10—C2—H21111.9H121—C12—H123111.9
C2—C3—C4104.93 (14)H122—C12—H123110.0
C2—C3—O8103.91 (14)C1—O13—C14108.60 (14)
C4—C3—O8109.08 (14)O13—C14—O15105.56 (15)
C2—C3—H31112.4O13—C14—C17110.45 (17)
C4—C3—H31114.6O15—C14—C17107.98 (17)
O8—C3—H31111.2O13—C14—C18107.55 (17)
C3—C4—O5105.01 (13)O15—C14—C18111.19 (18)
C3—C4—C6112.58 (15)C17—C14—C18113.81 (19)
O5—C4—C6111.65 (14)C14—O15—C16108.83 (13)
C3—C4—H41110.7C1—C16—O15103.25 (14)
O5—C4—H41107.5C1—C16—H161109.8
C6—C4—H41109.2O15—C16—H161109.8
C4—O5—C1109.09 (13)C1—C16—H162111.8
C4—C6—O7112.30 (15)O15—C16—H162109.3
C4—C6—H61107.7H161—C16—H162112.5
O7—C6—H61108.3C14—C17—H171107.2
C4—C6—H62107.4C14—C17—H172108.5
O7—C6—H62110.4H171—C17—H172108.4
H61—C6—H62110.6C14—C17—H173109.3
C6—O7—H1109.2H171—C17—H173112.4
C3—O8—C9108.05 (14)H172—C17—H173111.0
O8—C9—O10104.52 (15)C14—C18—H181108.9
O8—C9—C11110.51 (17)C14—C18—H182108.8
O10—C9—C11110.24 (17)H181—C18—H182109.5
O8—C9—C12107.93 (17)C14—C18—H183109.2
O10—C9—C12109.1 (2)H181—C18—H183109.2
C11—C9—C12114.1 (2)H182—C18—H183111.1
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O7—H1···O8i0.842.192.962 (2)152
Symmetry code: (i) x+1/2, y+3/2, z+1.
 

Acknowledgements

Financial support provided by the Xunta de Galicia (RS) is gratefully acknowledged.

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 citationBetteridge, P. W., Carruthers, J. R., Cooper, R. I., Prout, C. K. & Watkin, D. J. (2003). J. Appl. Cryst. 36, 1487.  Web of Science CrossRef IUCr Journals Google Scholar
First citationBols, M. (1996). Carbohydrate Building Blocks. New York: John Wiley & Sons, Inc.  Google Scholar
First citationCree, G. M. & Perlin, A. S. (1968). Can. J. Biochem. 46, 765–770.  CrossRef CAS PubMed Web of Science Google Scholar
First citationGranstrom, T. B., Takata, G., Tokuda, M. & Izumori, K. (2004). J. Biosci. Bioeng. 97, 89–94.  Web of Science CrossRef PubMed Google Scholar
First citationItoh, H. & Izumori, K. (1996). J. Ferment. Bioeng. 81, 351–353.  CrossRef CAS Web of Science Google Scholar
First citationItoh, H., Sato, I. & Izumori, K. (1995). J. Ferment. Bioeng. 80, 101–103.  CrossRef CAS Web of Science Google Scholar
First citationIzumori, K. (2002). Naturwissenschaften, 89, 120-124.  Web of Science CrossRef PubMed CAS Google Scholar
First citationJames, K. J., Tatchell, A. R. & Ray, P. R. (1967). J. Chem. Soc. C, pp. 2681–2686.  Google Scholar
First citationJoseph, C. C., Regeling, H., Zwanenburg, B. & Chittenden, G. J. F. (2002). Carbohydr. Res. 337, 1083–1087.  Web of Science CrossRef PubMed CAS Google Scholar
First citationLichtenthaler, F. W. & Peters, S. (2004). C. R. Chim. 7, 65–90.  Web of Science CrossRef CAS Google Scholar
First citationNonius (1997-2001). COLLECT. Nonius BV, Delft, The Netherlands.  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 citationPrisbe, E. J., Smejkal, J., Verdehyden, J. P. H. & Moffat, J. G. (1976). J. Org. Chem. 41, 1836–1846.  CrossRef PubMed CAS Web of Science Google Scholar
First citationSoengas, R., Izumori, K., Simone, M. I., Watkin, D. J., Skytte, U. P., Soetaert, W. & Fleet, G. W. J. (2005). Tetrahedron Lett. 46, 5755–5759.  Web of Science CrossRef CAS Google Scholar
First citationSoengas, R., Wormald, M. R., Dwek, R. A., Izumori, K., Watkin, D. J., Skytte, U. P. & Fleet, G. W. J. (2005). In preparation.  Google Scholar
First citationSteiger, M. & Reichstein, T. (1935). Helv. Chim. Acta, 18, 790–799.  CrossRef CAS Google Scholar
First citationSteiger, M. & Reichstein, T. (1936). Helv. Chim. Acta, 19, 184–189.  CrossRef CAS Google Scholar
First citationSun, Y., Hayakawa, S. & Izumori, K. (2004). J. Agric. Food. Chem. 52, 1293–1299.  Web of Science CrossRef PubMed CAS Google Scholar
First citationSun, Y., Hayakawa, S., Puangmanee, S. & Izumori, K. (2005). Food Chem. In the press (doi 10.1016/j.foodchem. 2005.01.033).  Google Scholar
First citationTakeshita, K., Suga, A., Takada, G. & Izumori, K. (2000). J. Biosci. Bioeng. 90, 453–455.  Web of Science CrossRef PubMed CAS Google Scholar
First citationTipson, S., Brady, R. & West, B. (1971). Carbohydr. Res. 16, 383–393.  CrossRef CAS Web of Science Google Scholar
First citationWatkin, D. J., Prout, C. K. & Pearce, L. J. (1996). CAMERON. Chemical Crystallography Laboratory, University of Oxford, England.  Google Scholar

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