N-Benzyl-6-de­oxy-3,6-imino­methyl­ene-1,2,3,5-O-tetra­acetyl-α-d-1(S)-epiallo­furan­ose

Qiurong Zhang; Chunli Wu; Pengyun Li; Weiyan Cheng; Hongmin Liu

doi:10.1107/S1600536811019702

. 2011 May 28;67(Pt 6):o1545. doi: 10.1107/S1600536811019702

N-Benzyl-6-deoxy-3,6-iminomethylene-1,2,3,5-O-tetraacetyl-α-d-1(S)-epiallofuranose

Qiurong Zhang ^a, Chunli Wu ^a, Pengyun Li ^a, Weiyan Cheng ^a, Hongmin Liu ^a,^*

PMCID: PMC3120565 PMID: 21754904

Abstract

The molecule of the title compound, C₂₂H₂₇NO₉, an azasugar derivative, consists of one benzene ring and two fused rings, which have the cis arrangement at the ring junctions, and gives a V-shaped geometry. The interplanar angle between the five- and six-membered rings is 65.69 (11)°. The crystal structure is stablized by weak intermolecular C—H⋯O hydrogen bonds.

Related literature

For the one-pot reaction used to obtain the title compound, see: Saito et al. (2002 ▶); Deshpandea et al. (2004 ▶). For the activity of azasugars, see: Compain et al. (2001 ▶, 2003 ▶). For their powerful inhibitory aptitude towards carbohydrate-processing enzymes, see: Guaragna et al. (2009 ▶).

Experimental

Crystal data

C₂₂H₂₇NO₉
M _r = 449.45
Monoclinic,
a = 8.1768 (16) Å
b = 9.0613 (18) Å
c = 15.591 (3) Å
β = 94.56 (3)°
V = 1151.5 (4) Å³
Z = 2
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 291 K
0.20 × 0.18 × 0.16 mm

Data collection

Rigaku R-AXIS-IV diffractometer
Absorption correction: multi-scan (SADABS: Sheldrick, 1996 ▶) T _min = 0.980, T _max = 0.984
4341 measured reflections
2503 independent reflections
2173 reflections with I > 2σ(I)
R _int = 0.033

Refinement

R[F ² > 2σ(F ²)] = 0.043
wR(F ²) = 0.107
S = 1.09
2503 reflections
290 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.15 e Å⁻³
Δρ_min = −0.13 e Å⁻³

Data collection: R-AXIS II Software (Rigaku, 1997 ▶); cell refinement: R-AXIS II Software; data reduction: R-AXIS II Software; 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: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811019702/zk2010sup1.cif

e-67-o1545-sup1.cif^{(23.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811019702/zk2010Isup2.hkl

e-67-o1545-Isup2.hkl^{(122.9KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C15—H15C⋯O6ⁱ	0.96	2.33	3.161 (5)	144

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Symmetry code: (i) Inline graphic .

Acknowledgments

We gratefully acknowledge the financial support of the National Natural Science Foundation of China (20572103).

supplementary crystallographic information

Comment

Owing to their powerful inhibitory aptitude towards carbohydrate processing enzymes, azasugars undoubtedly represent one of the most attractive classes of carbohydrate mimetics (Guaragna et al., 2009). As a contribution to the azasugars chemistry, we report here the crystal structure of the title compound, which was obtained under one-pot reaction (Sachin et al., 2004 and Saito et al., 2002) of N-benzyl-6-deoxy- 3,6-imino-methylene-1,2-O-isopropylidene-α-D-allofuranose.

In the crystal structure of the title compound (I) (Fig. 1), there are two fused rings (tetrahydrofuran ring and piperidine ring) having the cis arrangement at the ring junctions, giving a V-shaped molecule. The interplanar angle between the five and six membered rings is 65.69 (11)°. The torsion angles O1—C1—C2—C3, O1—C1—C2—O2 and C4—O4—C1—O1 around the carbon of hemiacetal group(C1) are 109.0 (2), -136.5 (2) and -137.1 (2)° respectively, which can confirm the hemiacetal group is β configuration. The molecules are linked into a framework by means of weak C—H···O hydrogen bonds (Table 1), one of whcih occurs between CH₃ of C5-acetoxy moiety and O atoms of carbonyl of C1-acetoxy moiety, and three of which occur among CH and CH₂groups of five and six membered rings and O atoms of carbonyl of three acetoxy moieties (Fig. 2).

Experimental

N-benzyl-6-deoxy-3,6-imino-methylene- 1,2-O-isopropylidene-α-D-allofuranose (2.0 g, 6.2 mmol) was dissolved in 85% acetic acid (10 ml). A solution of 15% hydrochoric acid was added to this mixture. The resulting mixture was stirred for about 6 h at ambient temperature. After the material was consumed, the reaction mixture was evaporated under reduced pressure to dryness to yield yellow solid, which was directly used without purification. Acetic anhydride (5 ml) was added to the yellow solid in dry pyridine (5 ml). The mixture was stirred for about 5 h at ambient temperature. The reaction mixture was adjusted to neutral with saturated NaHCO₃ under ice bath and filtered. The filtrate was extracted with EtOAc, dried (Na₂SO₄), and evaporated to obtained colorless oily. The oily was recrystallized from methanol to give the title compound as a white crystal. Crystals suitable for X-ray analysis were in two weeks by slow evaporation of methanol solution of the title compound at room temperature. ¹H NMR (400 MHz, CDCl₃) σ: 7.25–7.33 (5 H, m), 6.03 (1 H, s), 5.32 (1 H, s), 5.21 (1 H, m), 4.40 (1 H, d, J = 3.2 Hz), 3.62 (2 H, dd), 3.34 (1 H, d, J= 13.6 Hz), 2.81 (1 H, m), 2.54 (1 H, d, J = 13.6 Hz), 2.42 (1 H, m), 2.09 (3 H, s), 2.09(3 H, s), 2.08 (3 H, s), 2.07 (3 H, s), 2.04 (3 H, s); ¹³C NMR (100 MHz, CDCl₃) σ: 170.2, 169.3, 168.9, 168.6, 137.0, 128.7, 128.3, 127.4, 99.3, 80.2, 77.4, 76.5, 68.1, 61.4, 51.4, 49.9, 21.1, 21.1, 21.0, 20.5.