organic compounds
3,4-O-Isopropylidene-2-C-methyl-D-galactonolactone
aDepartment of Organic Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, England, and bDepartment of Chemical Crystallography, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, England
*Correspondence e-mail: sarah.jenkinson@chem.ox.ac.uk
X-ray crystallography unequivocally confirmed the stereochemistry of the 2-C-methyl group in the title molecule, C10H16O6, in which the 1,5-lactone ring exists in a boat conformation. The use of D-galactose in the synthesis determined the absolute stereochemistry. The crystal exists as O—H⋯O hydrogen-bonded layers in the ab plane, with each molecule acting as a donor and acceptor for two hydrogen bonds.
Related literature
For related literature on branched sugars, see: Booth et al. (2008, 2009); da Cruz et al. (2008); Hotchkiss et al. (2006, 2007); Jenkinson et al. (2007); Jones et al. (2007, 2008); Rao et al. (2008). For the conformations of related 1,5-lactones, see: Baird et al. (1987); Booth et al. (2007a,b); Bruce et al. (1990); Punzo et al. (2005, 2006).
Experimental
Crystal data
|
Refinement
|
Data collection: COLLECT (Nonius, 2001); cell DENZO/SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO/SCALEPACK; 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.
Supporting information
https://doi.org/10.1107/S1600536810001613/lh2976sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810001613/lh2976Isup2.hkl
The title compound was recrystallized by vapour diffusion from a mixture of ethyl acetate and cyclohexane: m.p. 423–429 K; [α]D25 +102.7 (c, 0.995 in MeOH).
In the absence of significant
Friedel pairs were merged and the was assigned from the starting material.One outlying reflection was omitted for the
as it was thought to be partially occluded by the beam stop.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.
2-C-Methyl branched sugars constitute a class of rare sugars with chemotherapeutic potential (Rao et al., 2008; Jones et al., 2008; Booth et al., 2008) as well as being chirons for the enantiospecfic synthesis of complex targets (Hotchkiss et al., 2006; Hotchkiss et al., 2007; da Cruz et al., 2008; Booth et al., 2009) including 2'-C-methyl
(Jenkinson et al., 2007). In a project to investigate the physical and biological properties of 2-C-methyl-D-galactose 4, D-galactose 1 [the use of which determines the absolute stereochemistry of the product] was converted by a number of steps to the 2 (Fig. 1) (Jones et al., 2007). The reaction of 2 with sodium cyanide in water gave a chain extension to afford a single isolated crystalline product 3 (Fig. 2). 3,4-O-Isopropylidene-1,5-lactones, such as 3, invariably crystallize in a boat conformation (Baird et al., 1987; Bruce et al., 1990; Punzo et al., 2005); the may be rationalized by the formation of the galactono-lactone 3 with less steric congestion (Punzo et al., 2006; Booth et al., 2007a; Booth et al., 2007b) than in the epimeric talono-lactone. The structure of 3 is confirmed by the X-ray crystallographic analysis reported in this paper. The lactone 3 is an intermediate for the unambiguous synthesis of 2-C-methyl-D-galactose 4.The 6-membered lactone ring adopts a boat conformation with the hydroxy group rather than the methyl group in the flagpole position (Fig. 2). The title compound exists as O—H···O hydrogen bonded layers of molecules in the ab-plane (Fig. 3, Fig. 4). Each molecule acts as a donor and acceptor for 2 hydrogen bonds. Only classical hydrogen bonds have been considered.
For related literature on branched sugars, see: Booth et al. (2008, 2009); da Cruz et al. (2008); Hotchkiss et al. (2006, 2007); Jenkinson et al. (2007); Jones et al. (2007, 2008); Rao et al. (2008). For the conformations of related 1,5-lactones, see: Baird et al. (1987); Booth et al. (2007a,b); Bruce et al. (1990); Punzo et al. (2005, 2006).
Data collection: COLLECT (Nonius, 2001); cell
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).C10H16O6 | F(000) = 248 |
Mr = 232.23 | Dx = 1.400 Mg m−3 |
Monoclinic, P21 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2yb | Cell parameters from 1236 reflections |
a = 6.0553 (2) Å | θ = 5–27° |
b = 11.3612 (4) Å | µ = 0.12 mm−1 |
c = 8.2946 (3) Å | T = 150 K |
β = 105.0854 (14)° | Plate, colourless |
V = 550.97 (3) Å3 | 0.50 × 0.40 × 0.10 mm |
Z = 2 |
Nonius KappaCCD diffractometer | 1229 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.028 |
ω scans | θmax = 27.5°, θmin = 5.2° |
Absorption correction: multi-scan (DENZO/SCALEPACK; Otwinowski & Minor, 1997) | h = −7→7 |
Tmin = 0.91, Tmax = 0.99 | k = −14→14 |
5558 measured reflections | l = −10→10 |
1314 independent reflections |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.029 | H-atom parameters constrained |
wR(F2) = 0.068 | Method = Modified Sheldrick w = 1/[σ2(F2) + (0.03P)2 + 0.19P], where P = [max(Fo2,0) + 2Fc2]/3 |
S = 0.98 | (Δ/σ)max = 0.000170 |
1313 reflections | Δρmax = 0.22 e Å−3 |
145 parameters | Δρmin = −0.18 e Å−3 |
1 restraint |
C10H16O6 | V = 550.97 (3) Å3 |
Mr = 232.23 | Z = 2 |
Monoclinic, P21 | Mo Kα radiation |
a = 6.0553 (2) Å | µ = 0.12 mm−1 |
b = 11.3612 (4) Å | T = 150 K |
c = 8.2946 (3) Å | 0.50 × 0.40 × 0.10 mm |
β = 105.0854 (14)° |
Nonius KappaCCD diffractometer | 1314 independent reflections |
Absorption correction: multi-scan (DENZO/SCALEPACK; Otwinowski & Minor, 1997) | 1229 reflections with I > 2σ(I) |
Tmin = 0.91, Tmax = 0.99 | Rint = 0.028 |
5558 measured reflections |
R[F2 > 2σ(F2)] = 0.029 | 1 restraint |
wR(F2) = 0.068 | H-atom parameters constrained |
S = 0.98 | Δρmax = 0.22 e Å−3 |
1313 reflections | Δρmin = −0.18 e Å−3 |
145 parameters |
x | y | z | Uiso*/Ueq | ||
O1 | 0.1833 (2) | 0.44365 (15) | 0.34373 (17) | 0.0239 | |
C2 | 0.2057 (3) | 0.50024 (18) | 0.1948 (2) | 0.0213 | |
C3 | 0.3440 (3) | 0.61260 (18) | 0.2310 (2) | 0.0182 | |
O4 | 0.5789 (2) | 0.57762 (14) | 0.31079 (16) | 0.0207 | |
C5 | 0.7424 (3) | 0.65953 (18) | 0.3392 (2) | 0.0190 | |
O6 | 0.9366 (2) | 0.63080 (16) | 0.41067 (17) | 0.0258 | |
C7 | 0.6739 (3) | 0.78590 (18) | 0.2822 (2) | 0.0185 | |
O8 | 0.5348 (2) | 0.82928 (15) | 0.38453 (17) | 0.0224 | |
C9 | 0.8833 (3) | 0.86206 (19) | 0.2930 (3) | 0.0236 | |
C10 | 0.5160 (3) | 0.78355 (18) | 0.1047 (2) | 0.0193 | |
C11 | 0.3342 (3) | 0.68457 (18) | 0.0755 (2) | 0.0190 | |
O12 | 0.3897 (2) | 0.61111 (14) | −0.04874 (16) | 0.0232 | |
C13 | 0.5062 (3) | 0.6857 (2) | −0.1390 (2) | 0.0225 | |
O14 | 0.6490 (2) | 0.75665 (14) | −0.00941 (15) | 0.0220 | |
C15 | 0.3374 (4) | 0.7604 (2) | −0.2640 (2) | 0.0300 | |
C16 | 0.6590 (4) | 0.6125 (2) | −0.2164 (3) | 0.0307 | |
H21 | 0.0514 | 0.5221 | 0.1280 | 0.0253* | |
H22 | 0.2831 | 0.4457 | 0.1327 | 0.0254* | |
H31 | 0.2876 | 0.6635 | 0.3096 | 0.0192* | |
H91 | 0.8339 | 0.9420 | 0.2601 | 0.0333* | |
H93 | 0.9791 | 0.8665 | 0.4043 | 0.0339* | |
H92 | 0.9711 | 0.8323 | 0.2182 | 0.0336* | |
H101 | 0.4445 | 0.8626 | 0.0784 | 0.0218* | |
H111 | 0.1751 | 0.7172 | 0.0354 | 0.0205* | |
H152 | 0.4259 | 0.8092 | −0.3237 | 0.0421* | |
H151 | 0.2464 | 0.8116 | −0.2113 | 0.0424* | |
H153 | 0.2412 | 0.7087 | −0.3440 | 0.0423* | |
H161 | 0.7445 | 0.6676 | −0.2693 | 0.0459* | |
H163 | 0.7596 | 0.5680 | −0.1332 | 0.0464* | |
H162 | 0.5654 | 0.5645 | −0.3003 | 0.0462* | |
H81 | 0.6206 | 0.8478 | 0.4729 | 0.0319* | |
H11 | 0.0902 | 0.4790 | 0.3908 | 0.0358* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0268 (7) | 0.0221 (7) | 0.0249 (7) | 0.0017 (6) | 0.0104 (6) | 0.0072 (6) |
C2 | 0.0241 (9) | 0.0199 (9) | 0.0194 (9) | −0.0019 (8) | 0.0050 (7) | 0.0033 (7) |
C3 | 0.0163 (8) | 0.0196 (9) | 0.0185 (8) | 0.0022 (7) | 0.0043 (7) | 0.0024 (7) |
O4 | 0.0184 (6) | 0.0193 (6) | 0.0232 (7) | 0.0023 (5) | 0.0035 (5) | 0.0035 (5) |
C5 | 0.0203 (9) | 0.0226 (10) | 0.0148 (8) | 0.0012 (7) | 0.0063 (7) | −0.0010 (7) |
O6 | 0.0196 (6) | 0.0291 (7) | 0.0272 (7) | 0.0038 (6) | 0.0031 (5) | 0.0015 (6) |
C7 | 0.0194 (8) | 0.0196 (9) | 0.0170 (8) | 0.0014 (7) | 0.0057 (7) | −0.0032 (7) |
O8 | 0.0222 (6) | 0.0250 (7) | 0.0207 (6) | 0.0006 (6) | 0.0068 (5) | −0.0069 (5) |
C9 | 0.0227 (9) | 0.0232 (10) | 0.0249 (10) | −0.0026 (8) | 0.0063 (8) | −0.0035 (8) |
C10 | 0.0235 (9) | 0.0176 (9) | 0.0171 (8) | 0.0001 (8) | 0.0058 (7) | 0.0002 (7) |
C11 | 0.0214 (9) | 0.0181 (9) | 0.0176 (8) | −0.0007 (7) | 0.0051 (7) | −0.0003 (7) |
O12 | 0.0324 (7) | 0.0206 (7) | 0.0185 (6) | −0.0065 (6) | 0.0100 (6) | −0.0021 (5) |
C13 | 0.0308 (10) | 0.0228 (9) | 0.0144 (8) | −0.0088 (8) | 0.0070 (7) | −0.0017 (7) |
O14 | 0.0252 (7) | 0.0249 (7) | 0.0173 (6) | −0.0066 (6) | 0.0082 (5) | −0.0036 (5) |
C15 | 0.0354 (11) | 0.0336 (12) | 0.0187 (9) | −0.0047 (9) | 0.0028 (8) | 0.0035 (8) |
C16 | 0.0400 (11) | 0.0315 (11) | 0.0239 (10) | −0.0037 (9) | 0.0140 (9) | −0.0059 (9) |
O1—C2 | 1.430 (2) | C9—H92 | 0.976 |
O1—H11 | 0.864 | C10—C11 | 1.548 (3) |
C2—C3 | 1.513 (3) | C10—O14 | 1.426 (2) |
C2—H21 | 0.985 | C10—H101 | 0.996 |
C2—H22 | 0.997 | C11—O12 | 1.432 (2) |
C3—O4 | 1.459 (2) | C11—H111 | 1.005 |
C3—C11 | 1.516 (3) | O12—C13 | 1.432 (2) |
C3—H31 | 0.995 | C13—O14 | 1.439 (2) |
O4—C5 | 1.334 (2) | C13—C15 | 1.513 (3) |
C5—O6 | 1.216 (2) | C13—C16 | 1.506 (3) |
C5—C7 | 1.534 (3) | C15—H152 | 0.990 |
C7—O8 | 1.430 (2) | C15—H151 | 0.979 |
C7—C9 | 1.519 (3) | C15—H153 | 0.961 |
C7—C10 | 1.533 (3) | C16—H161 | 0.985 |
O8—H81 | 0.808 | C16—H163 | 0.940 |
C9—H91 | 0.973 | C16—H162 | 0.947 |
C9—H93 | 0.956 | ||
C2—O1—H11 | 113.6 | C7—C10—O14 | 108.81 (14) |
O1—C2—C3 | 112.29 (15) | C11—C10—O14 | 103.99 (14) |
O1—C2—H21 | 108.0 | C7—C10—H101 | 108.8 |
C3—C2—H21 | 107.1 | C11—C10—H101 | 111.7 |
O1—C2—H22 | 109.3 | O14—C10—H101 | 109.7 |
C3—C2—H22 | 108.4 | C10—C11—C3 | 112.96 (15) |
H21—C2—H22 | 111.8 | C10—C11—O12 | 104.22 (14) |
C2—C3—O4 | 106.51 (15) | C3—C11—O12 | 109.48 (15) |
C2—C3—C11 | 112.89 (15) | C10—C11—H111 | 111.4 |
O4—C3—C11 | 110.51 (14) | C3—C11—H111 | 107.6 |
C2—C3—H31 | 110.7 | O12—C11—H111 | 111.2 |
O4—C3—H31 | 108.7 | C11—O12—C13 | 105.74 (14) |
C11—C3—H31 | 107.5 | O12—C13—O14 | 102.88 (13) |
C3—O4—C5 | 118.76 (15) | O12—C13—C15 | 110.69 (16) |
O4—C5—O6 | 118.55 (17) | O14—C13—C15 | 111.39 (17) |
O4—C5—C7 | 118.00 (15) | O12—C13—C16 | 109.71 (17) |
O6—C5—C7 | 123.44 (17) | O14—C13—C16 | 108.15 (17) |
C5—C7—O8 | 107.07 (14) | C15—C13—C16 | 113.47 (16) |
C5—C7—C9 | 111.12 (15) | C13—O14—C10 | 106.42 (14) |
O8—C7—C9 | 112.38 (15) | C13—C15—H152 | 107.5 |
C5—C7—C10 | 109.30 (14) | C13—C15—H151 | 112.7 |
O8—C7—C10 | 105.05 (14) | H152—C15—H151 | 109.4 |
C9—C7—C10 | 111.64 (15) | C13—C15—H153 | 108.1 |
C7—O8—H81 | 106.8 | H152—C15—H153 | 107.9 |
C7—C9—H91 | 108.9 | H151—C15—H153 | 111.2 |
C7—C9—H93 | 112.0 | C13—C16—H161 | 106.9 |
H91—C9—H93 | 106.6 | C13—C16—H163 | 109.6 |
C7—C9—H92 | 110.5 | H161—C16—H163 | 110.7 |
H91—C9—H92 | 108.9 | C13—C16—H162 | 108.3 |
H93—C9—H92 | 109.8 | H161—C16—H162 | 108.8 |
C7—C10—C11 | 113.78 (14) | H163—C16—H162 | 112.3 |
D—H···A | D—H | H···A | D···A | D—H···A |
C2—H22···O14i | 1.00 | 2.46 | 3.391 (3) | 155 |
C3—H31···O6ii | 1.00 | 2.51 | 3.204 (3) | 127 |
C15—H153···O6iii | 0.96 | 2.52 | 3.454 (3) | 163 |
O8—H81···O1iv | 0.81 | 1.99 | 2.771 (3) | 162 |
O1—H11···O6ii | 0.86 | 1.99 | 2.737 (3) | 145 |
Symmetry codes: (i) −x+1, y−1/2, −z; (ii) x−1, y, z; (iii) x−1, y, z−1; (iv) −x+1, y+1/2, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C10H16O6 |
Mr | 232.23 |
Crystal system, space group | Monoclinic, P21 |
Temperature (K) | 150 |
a, b, c (Å) | 6.0553 (2), 11.3612 (4), 8.2946 (3) |
β (°) | 105.0854 (14) |
V (Å3) | 550.97 (3) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.12 |
Crystal size (mm) | 0.50 × 0.40 × 0.10 |
Data collection | |
Diffractometer | Nonius KappaCCD |
Absorption correction | Multi-scan (DENZO/SCALEPACK; Otwinowski & Minor, 1997) |
Tmin, Tmax | 0.91, 0.99 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5558, 1314, 1229 |
Rint | 0.028 |
(sin θ/λ)max (Å−1) | 0.650 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.029, 0.068, 0.98 |
No. of reflections | 1313 |
No. of parameters | 145 |
No. of restraints | 1 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.22, −0.18 |
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).
D—H···A | D—H | H···A | D···A | D—H···A |
O8—H81···O1i | 0.81 | 1.99 | 2.771 (3) | 162 |
O1—H11···O6ii | 0.86 | 1.99 | 2.737 (3) | 145 |
Symmetry codes: (i) −x+1, y+1/2, −z+1; (ii) x−1, y, z. |
Acknowledgements
We would like to thank the Chemical Crystallography department and ALT at Oxford University for use of the difractometers.
References
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2-C-Methyl branched sugars constitute a class of rare sugars with chemotherapeutic potential (Rao et al., 2008; Jones et al., 2008; Booth et al., 2008) as well as being chirons for the enantiospecfic synthesis of complex targets (Hotchkiss et al., 2006; Hotchkiss et al., 2007; da Cruz et al., 2008; Booth et al., 2009) including 2'-C-methyl nucleosides (Jenkinson et al., 2007). In a project to investigate the physical and biological properties of 2-C-methyl-D-galactose 4, D-galactose 1 [the use of which determines the absolute stereochemistry of the product] was converted by a number of steps to the lactols 2 (Fig. 1) (Jones et al., 2007). The reaction of 2 with sodium cyanide in water gave a chain extension to afford a single isolated crystalline product 3 (Fig. 2). 3,4-O-Isopropylidene-1,5-lactones, such as 3, invariably crystallize in a boat conformation (Baird et al., 1987; Bruce et al., 1990; Punzo et al., 2005); the diastereoselectivity may be rationalized by the formation of the galactono-lactone 3 with less steric congestion (Punzo et al., 2006; Booth et al., 2007a; Booth et al., 2007b) than in the epimeric talono-lactone. The structure of 3 is confirmed by the X-ray crystallographic analysis reported in this paper. The lactone 3 is an intermediate for the unambiguous synthesis of 2-C-methyl-D-galactose 4.
The 6-membered lactone ring adopts a boat conformation with the hydroxy group rather than the methyl group in the flagpole position (Fig. 2). The title compound exists as O—H···O hydrogen bonded layers of molecules in the ab-plane (Fig. 3, Fig. 4). Each molecule acts as a donor and acceptor for 2 hydrogen bonds. Only classical hydrogen bonds have been considered.