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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 61| Part 10| October 2005| Pages o3302-o3303
doi:10.1107/S1600536805028837

3,5-O-Iso­propyl­­idene-2-C-methyl-D-xylonolactone

CROSSMARK_Color_square_no_text.svg
David J. Watkin,a* Loren L. Parry,a David J. Hotchkiss,b Vanessa Eastwick-Fieldc and George W. J. Fleetb

aChemical Crystallography, Chemitry Research Laboratory, University of Oxford, Oxford, OX1 3TA, England, bDepartment of Organic Chemistry, Chemical Research Laboratory, Oxford University, Mansfield Road, Oxford OX1 3TA, England, and cCMS Chemicals, 9 Milton Park, Abingdon, Oxon, OX14 4RR, England
*Correspondence e-mail: david.watkin@chem.ox.ac.England

(Received 6 September 2005; accepted 12 September 2005; online 17 September 2005)

The ring size of both the lactone and the ketal protecting group in the title compound, C9H14O5, have been established by X-ray crystallographic analysis. The crystal structure consists of hydrogen-bonded spirals parallel to the b axis.

Comment

Almost all carbohydrate scaffolds contain linear carbon chains (Lichtenthaler & Peters, 2004[Lichtenthaler, F. W. & Peters, S. (2004). Compt. Rend. Chim. 7, 65-90.]). The two exceptions that do provide carbohydrates with branched carbon chains are (i) the Kiliani reaction on ketoses which provides efficient access to a set of 2-C-hydroxy­methylaldonolactones (Hotchkiss et al., 2004[Hotchkiss, D., Soengas, R., Simone, M. I., van Ameijde, J., Hunter, S., Cowley, A. R. & Fleet, G. W. J. (2004). Tetrahedron Lett. 45, 9461-9464.]; Soengas 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.]), and (ii) the treatment of sugars with base to give 2-C-methyl aldonic acids, also known as saccharinic acids (Bols, 1996[Bols, M. (1996). Carbohydrate Building Blocks. New York: John Wiley & Sons, Inc.]). However, the reaction of base with sugars is complex: glucose gives a mixture of more than 50 compounds on treatment with calcium hydroxide, of which branched sugars comprise a very small percentage (Yang & Montgomery, 1996[Yang, B. Y. & Montgomery, R. (1996). Carbohyd. Res. 280, 27-45.]). Better yields are obtained from ketoses; however, even the optimized conditions (several weeks under careful control in a laborious procedure) for treatment of D-fructose with calcium hydroxide afford 2-C-methyl-D-ribonolactone in only 11% yield (Whistler & BeMiller, 1963[Whistler, R. L. & BeMiller, J. N. (1963). Method Carbohyd. Chem. 2, 484-485.]). Very low yields of branched lactones have been isolated from similar treatment of L-sorbose (Ishizu et al., 1972[Ishizu, A., Yoshida, K. & Yamazaki, N. (1972). Carbohydr. Res. 23, 23-29.]). A further ketohexose, D-tagatose (1), has recently become available in quantity as a new food additive (Skytte, 2002[Skytte, U. P. (2002). Cereal Foods World, 47, 224-227.]); (1) has the potential for making 2-C-methyl-D-xylonolactone as a branch­ed-sugar building block under green environmentally friendly conditions. Treatment of D-tagatose with aqueous calcium hydroxide produces a very complex mixture of products. In order to identify the branched-chain sugar products, it was necessary to make authentic samples of easily crystallized derivatives.

[Scheme 1]

A crystalline acetonide was obtained from treatment of 2-C-methyl-D-xylonolactone with acetone in the presence of acid. The absolute stereochemistry of (2) is determined by using D-tagatose (1) as the starting material; however, there are ambiguities in the synthesis with regard to the relative stereochemistry at C-2 of the lactone, the ring size of the lactone and the ring size of the ketal. X-ray crystallographic analysis removed all the ambiguities and firmly established the structure of the acetonide as (2).

[Figure 1]
Figure 1
The title compound, with displacement ellipsoids drawn at the 50% probability level. H atoms are shown as spheres of arbitary radius.
[Figure 2]
Figure 2
Projection of the structure perpendicular to the b axis, showing the mol­ecules linked into hydrogen-bonded spirals parallel to b.

Experimental

The acetonide (2) was prepared as in the Comment section and crystallized from ethyl acetate:cyclo­hexane (m.p. 428–431 K) as long fibrous needles. [α]D23 +82.2 (c 0.67 in CHCl3).

Crystal data

  • C9H14O5

  • Mr = 202.21

  • Monoclinic, P 21

  • a = 8.3764 (3) Å

  • b = 5.9861 (2) Å

  • c = 10.4690 (4) Å

  • β = 110.0336 (12)°

  • V = 493.17 (3) Å3

  • Z = 2

  • Dx = 1.362 Mg m−3

  • Mo Kα radiation

  • Cell parameters from 1419 reflections

  • θ = 5–30°

  • μ = 0.11 mm−1

  • T = 150 K

  • Lath, colourless

  • 1.00 × 0.28 × 0.12 mm
Data collection

  • Nonius KappaCCD 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 = 0.81, Tmax = 0.99

  • 7941 measured reflections

  • 1549 independent reflections

  • 1549 reflections with I > −3.0σ(I)

  • Rint = 0.034

  • θmax = 30.0°

  • h = −11 → 11

  • k = −8 → 8

  • l = −14 → 14
Refinement

  • Refinement on F2

  • R[F2 > 2σ(F2)] = 0.044

  • wR(F2) = 0.074

  • S = 0.94

  • 1549 reflections

  • 127 parameters

  • H-atom parameters constrained

  • w = 1/[σ2(F2) + (0.04P)2 + 0.03P], where P = (max(Fo2,0) + 2Fc2)/3

  • (Δ/σ)max < 0.001

  • Δρmax = 0.28 e Å−3

  • Δρmin = −0.24 e Å−3

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

D—H⋯A D—H H⋯A D⋯A D—H⋯A
O14—H1⋯O6i 0.84 2.00 2.837 (2) 176
Symmetry code: (i) [-x+1, y-{\script{1\over 2}}, -z].

In the absence of significant anomalous scattering, Friedel pairs were merged, and the absolute configuration assigned from the known staring materials.

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 to regularize their geometry (C—H in the range 0.93–0.98 and O—H = 0.82 Å) and displacement param­eters [Uiso(H) in the range 1.2–1.5 times Ueq of the parent 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, 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

Crystal structure: contains datablocks 2, global. DOI: 10.1107/S1600536805028837/at6030sup1.cif

Structure factors: contains datablock 2. DOI: 10.1107/S1600536805028837/at60302sup2.hkl


Comment top

Almost all carbohydrate scaffolds contain linear carbon chains (Lichtenthaler & Peters, 2004). The two exceptions that do provide carbohydrates with branched carbon chains are (i) the Kiliani reaction on ketoses which provides efficient access to a set of 2-C-hydroxymethyl-aldonolactones (Hotchkiss et al., 2004; Soengas et al., 2005), and (ii) the treatment of sugars with base to give 2-C-methyl aldonic acids, also known as saccharinic acids (Bols, 1996). However the reaction of base with sugars is complex: glucose gives a mixture of more than 50 compounds on treatment with calcium hydroxide, of which branched sugars comprise a very small percentage (Yang & Montgomery, 1996). Better yields are obtained from ketoses; however, even the optimized conditions (several weeks under careful control in a laborious procedure) for treatment of D-fructose with calcium hydroxide afford 2-C-methyl-D-ribonolactone in only 11% yield (Whistler & BeMiller, 1963). Very low yields of branched lactones have been isolated from similar treatment of L-sorbose (Ishizu et al., 1972). A further ketohexose, D-tagatose (1), has recently become available in quantity as a new food additive (Skytte, 2002); (1) has the potential for making 2-C-methyl-D-xylonolactone as a branched-sugar building block under green environmentally friendly conditions. Treatment of D-tagatose with aqueous calcium hydroxide produces a very complex mixture of products. In order to identify the branched-chain sugar products, it was necessary to make authentic samples of easily crystallized derivatives.

A crystalline acetonide was obtained from treatment of 2-C-methyl-D-xylonolactone with acetone in the presence of acid. The absolute stereochemistry of (2) is determined by using D-tagatose (1) as the starting material; however, there are ambiguities in the synthesis with regard to the relative stereochemistry at C-2 of the lactone, the ring size of the lactone and the ring size of the ketal. X-ray crystallographic analysis removed all the ambiguities and firmly established the structure of the acetonide as (2).

Experimental top

The acetonide (2) was prepared as in the Comment section and crystallized from ethyl acetate:cyclohexane (m.p. 428–431 K) as long fibrous needles. [α]D23 +82.2 (c 0.67 in CHCl3)

Refinement top

In the absence of significant anomalous scattering, Friedel pairs were merged, and the absolute configuration assigned from the known staring materials.

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 to regularize their geometry (C—H in the range 0.93–0.98 and O—H = 0.82 Å) and displacement parameters [Uiso(H) in the range 1.2–1.5 times Ueq of the parent atom], after which they were refined with riding constraints.

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.

Figures top
[Figure 1] Fig. 1. The title compound, with displacement ellipsoids drawn at the 50% probability level. H atoms are shown as spheres of arbitary radius.
[Figure 2] Fig. 2. Projection of the structure perpendicular to the b axis, showing the molecules linked into hydrogen-bonded spirals parallel to b.
3,5-O-Isopropylidene-2-C-methyl-D-xylonolactone top
Crystal data top
C9H14O5F(000) = 216
Mr = 202.21Dx = 1.362 Mg m−3
Monoclinic, P21Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ybCell parameters from 1419 reflections
a = 8.3764 (3) Åθ = 5–30°
b = 5.9861 (2) ŵ = 0.11 mm−1
c = 10.4690 (4) ÅT = 150 K
β = 110.0336 (12)°Plate, colourless
V = 493.17 (3) Å31.00 × 0.28 × 0.12 mm
Z = 2
Data collection top
Nonius KappaCCD
diffractometer		1549 reflections with I > −3.0σ(I)
Graphite monochromatorRint = 0.034
ω scansθmax = 30.0°, θmin = 5.1°
Absorption correction: multi-scan
(DENZO/SCALEPACK; Otwinowski & Minor, 1997)		h = −11→11
Tmin = 0.81, Tmax = 0.99k = −8→8
7941 measured reflectionsl = −14→14
1549 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)] = 0.044H-atom parameters constrained
wR(F2) = 0.074 w = 1/[σ2(F2) + ( 0.04P)2 + 0.03P],
where P = (max(Fo2,0) + 2Fc2)/3
S = 0.94(Δ/σ)max = 0.000276
1549 reflectionsΔρmax = 0.28 e Å−3
127 parametersΔρmin = −0.24 e Å−3
1 restraint
Crystal data top
C9H14O5V = 493.17 (3) Å3
Mr = 202.21Z = 2
Monoclinic, P21Mo Kα radiation
a = 8.3764 (3) ŵ = 0.11 mm−1
b = 5.9861 (2) ÅT = 150 K
c = 10.4690 (4) Å1.00 × 0.28 × 0.12 mm
β = 110.0336 (12)°
Data collection top
Nonius KappaCCD
diffractometer		1549 independent reflections
Absorption correction: multi-scan
(DENZO/SCALEPACK; Otwinowski & Minor, 1997)		1549 reflections with I > −3.0σ(I)
Tmin = 0.81, Tmax = 0.99Rint = 0.034
7941 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0441 restraint
wR(F2) = 0.074H-atom parameters constrained
S = 0.94Δρmax = 0.28 e Å−3
1549 reflectionsΔρmin = −0.24 e Å−3
127 parameters
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
C150.3718 (2)0.6651 (3)0.12110 (16)0.0178
C20.25213 (19)0.5660 (3)0.18739 (15)0.0184
C30.1006 (2)0.7239 (3)0.13919 (17)0.0224
O40.17777 (14)0.94293 (19)0.13389 (12)0.0229
C50.3328 (2)0.9145 (3)0.12495 (15)0.0186
O60.41821 (15)1.0723 (2)0.11673 (12)0.0263
C7−0.0008 (2)0.7359 (3)0.23305 (18)0.0293
O80.10426 (16)0.7433 (2)0.37196 (12)0.0287
C90.2271 (2)0.5693 (3)0.41041 (17)0.0241
O100.33568 (13)0.5859 (2)0.33001 (10)0.0202
C110.1474 (3)0.3382 (3)0.3982 (2)0.0342
C120.3401 (3)0.6203 (4)0.55389 (17)0.0359
C130.55828 (19)0.6121 (3)0.18621 (16)0.0223
O140.30492 (14)0.6050 (2)−0.02003 (10)0.0248
H210.22100.40950.16080.0219*
H310.02570.68320.04540.0259*
H71−0.07340.60260.21710.0361*
H72−0.07030.87030.21350.0359*
H1110.23520.22730.42930.0549*
H1120.08020.30680.30290.0551*
H1130.07430.33310.45480.0544*
H1210.43350.50660.58250.0553*
H1220.27160.60880.61380.0542*
H1230.38850.76810.55870.0549*
H1310.62080.69640.13940.0328*
H1320.57560.45290.17700.0330*
H1330.59670.65570.28030.0330*
H10.38750.5895−0.04720.0382*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C150.0187 (8)0.0185 (7)0.0161 (8)−0.0012 (6)0.0057 (6)−0.0027 (6)
C20.0198 (7)0.0176 (7)0.0175 (7)−0.0014 (6)0.0061 (6)−0.0023 (6)
C30.0171 (8)0.0232 (8)0.0247 (8)−0.0016 (7)0.0042 (6)0.0007 (6)
O40.0227 (6)0.0202 (6)0.0271 (6)0.0043 (5)0.0101 (5)0.0042 (5)
C50.0214 (8)0.0218 (8)0.0136 (7)0.0006 (6)0.0072 (6)0.0004 (6)
O60.0342 (7)0.0210 (6)0.0286 (6)−0.0032 (6)0.0172 (5)0.0009 (5)
C70.0202 (8)0.0336 (10)0.0359 (10)0.0032 (8)0.0117 (7)0.0050 (8)
O80.0310 (7)0.0287 (7)0.0327 (7)0.0044 (5)0.0190 (6)0.0012 (6)
C90.0281 (8)0.0247 (8)0.0255 (8)−0.0008 (7)0.0168 (7)0.0023 (7)
O100.0204 (5)0.0240 (6)0.0170 (5)0.0005 (5)0.0073 (4)0.0024 (5)
C110.0439 (12)0.0287 (10)0.0374 (11)−0.0060 (9)0.0234 (9)0.0037 (8)
C120.0444 (11)0.0417 (11)0.0241 (9)−0.0041 (9)0.0149 (8)0.0001 (8)
C130.0198 (7)0.0230 (8)0.0248 (8)−0.0003 (7)0.0087 (6)−0.0008 (7)
O140.0260 (6)0.0315 (7)0.0179 (5)−0.0026 (5)0.0088 (4)−0.0058 (5)
Geometric parameters (Å, º) top
C15—C21.522 (2)O8—C91.422 (2)
C15—C51.532 (2)C9—O101.4391 (19)
C15—C131.508 (2)C9—C111.522 (3)
C15—O141.4350 (18)C9—C121.507 (2)
C2—C31.523 (2)C11—H1110.961
C2—O101.4204 (18)C11—H1120.981
C2—H210.987C11—H1130.988
C3—O41.471 (2)C12—H1211.002
C3—C71.504 (2)C12—H1220.987
C3—H310.997C12—H1230.967
O4—C51.3447 (19)C13—H1310.972
C5—O61.206 (2)C13—H1320.974
C7—O81.419 (2)C13—H1330.961
C7—H710.982O14—H10.838
C7—H720.973
C2—C15—C5100.84 (13)C7—O8—C9113.68 (13)
C2—C15—C13117.01 (13)O8—C9—O10108.96 (13)
C5—C15—C13112.97 (14)O8—C9—C11112.85 (14)
C2—C15—O14106.60 (12)O10—C9—C11111.11 (15)
C5—C15—O14105.06 (13)O8—C9—C12106.30 (15)
C13—C15—O14113.04 (13)O10—C9—C12105.17 (14)
C15—C2—C3102.22 (13)C11—C9—C12112.06 (16)
C15—C2—O10106.39 (12)C9—O10—C2115.24 (12)
C3—C2—O10110.53 (13)C9—C11—H111109.7
C15—C2—H21113.2C9—C11—H112110.0
C3—C2—H21112.7H111—C11—H112108.6
O10—C2—H21111.3C9—C11—H113108.8
C2—C3—O4103.79 (12)H111—C11—H113109.5
C2—C3—C7113.95 (15)H112—C11—H113110.2
O4—C3—C7109.62 (15)C9—C12—H121108.7
C2—C3—H31110.3C9—C12—H122108.4
O4—C3—H31108.5H121—C12—H122109.1
C7—C3—H31110.4C9—C12—H123110.2
C3—O4—C5109.70 (12)H121—C12—H123109.6
C15—C5—O4110.20 (14)H122—C12—H123110.8
C15—C5—O6128.67 (15)C15—C13—H131108.5
O4—C5—O6121.08 (15)C15—C13—H132109.1
C3—C7—O8112.36 (14)H131—C13—H132109.5
C3—C7—H71107.8C15—C13—H133109.7
O8—C7—H71109.3H131—C13—H133109.0
C3—C7—H72109.5H132—C13—H133110.9
O8—C7—H72107.8C15—O14—H1107.5
H71—C7—H72110.1
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O14—H1···O6i0.842.002.837 (2)176
Symmetry code: (i) −x+1, y−1/2, −z.

Experimental details

Crystal data
Chemical formulaC9H14O5
Mr202.21
Crystal system, space groupMonoclinic, P21
Temperature (K)150
a, b, c (Å)8.3764 (3), 5.9861 (2), 10.4690 (4)
β (°) 110.0336 (12)
V (Å3)493.17 (3)
Z2
Radiation typeMo Kα
µ (mm−1)0.11
Crystal size (mm)1.00 × 0.28 × 0.12
Data collection
DiffractometerNonius KappaCCD
diffractometer
Absorption correctionMulti-scan
(DENZO/SCALEPACK; Otwinowski & Minor, 1997)
Tmin, Tmax0.81, 0.99
No. of measured, independent and
observed [I > −3.0σ(I)] reflections		7941, 1549, 1549
Rint0.034
(sin θ/λ)max (Å−1)0.703
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.044, 0.074, 0.94
No. of reflections1549
No. of parameters127
No. of restraints1
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å−3)0.28, −0.24

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

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O14—H1···O6i0.8382.0002.837 (2)176.4
Symmetry code: (i) −x+1, y−1/2, −z.
 

Acknowledgements

Financial support from the EPSRC (to DH) is gratefully acknowledged.

References

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ISSN: 2056-9890
Volume 61| Part 10| October 2005| Pages o3302-o3303
doi:10.1107/S1600536805028837
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