1,2,3,3′,4′,6′-Hexaacetyl-4,6-O-benzyl­idenesucrose

Marco A Brito-Arias; Miguel Soto-Ortega; Efrén V García-Báez

doi:10.1107/S1600536811002546

. 2011 Jan 26;67(Pt 2):o486. doi: 10.1107/S1600536811002546

1,2,3,3′,4′,6′-Hexaacetyl-4,6-O-benzylidenesucrose

Marco A Brito-Arias ^a,^*, Miguel Soto-Ortega ^a, Efrén V García-Báez ^a

PMCID: PMC3051458 PMID: 21523142

Abstract

In the title compound, C₃₁H₃₈O₁₇, the 1,3-dioxane and pyranoside rings both show ⁴ C ₁ chair conformations while for the d-fructofuranoside moiety an envelop 3E conformation is observed. The phenyl ring is oriented almost perpendicular to the 1,3-dioxane ring [dihedral angle = 79.3 (2)°], and the acetate groups are equatorial for the pyranoside ring and axial for the furanoside ring. The analysis of potential hydrogen bonds shows both intra- and intermolecular C—H⋯O contacts to be present.

Related literature

For sucrose and sucralose, see: Robyt (1998 ▶); Fairclough et al. (1995 ▶). For sucrose derivatives as potential pharmaceutically active substances, see: El Sayed & El Nemr (2005 ▶); Furneaux et al. (1993 ▶). For details of O-glycosidic bonds, see: Brito-Arias et al. (2007 ▶). For conformational analysis of five and six-membered rings, see: Cremer & Pople (1975 ▶); Evans & Boeyens (1989 ▶).

Experimental

Crystal data

C₃₁H₃₈O₁₇
M _r = 682.61
Orthorhombic,
a = 8.2018 (2) Å
b = 18.6416 (3) Å
c = 22.0994 (5) Å
V = 3378.88 (12) Å³
Z = 4
Mo Kα radiation
μ = 0.11 mm⁻¹
T = 293 K
0.40 × 0.30 × 0.20 mm

Data collection

Oxford Diffraction CrysAlis CCD diffractometer
10881 measured reflections
5582 independent reflections
4757 reflections with I > 2σ(I)
R _int = 0.019

Refinement

R[F ² > 2σ(F ²)] = 0.036
wR(F ²) = 0.091
S = 1.03
5582 reflections
440 parameters
H-atom parameters constrained
Δρ_max = 0.25 e Å⁻³
Δρ_min = −0.15 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2003 ▶); cell refinement: CrysAlis CCD; data reduction: CrysAlis RED (Oxford Diffraction, 2003 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶) and Mercury (Macrae et al., 2006 ▶); software used to prepare material for publication: SHELXL97, PLATON (Spek, 2009 ▶) and WinGX2003 (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811002546/su2240sup1.cif

e-67-0o486-sup1.cif^{(36.6KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811002546/su2240Isup2.hkl

e-67-0o486-Isup2.hkl^{(267.8KB, 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
C1—H1⋯O10	0.98	2.49	3.108 (3)	121
C1—H1⋯O15ⁱ	0.98	2.56	3.399 (3)	143
C15—H15⋯O17	0.98	2.49	3.309 (3)	141
C25—H25A⋯O12ⁱⁱ	0.96	2.51	3.343 (3)	145
C29—H29C⋯O12ⁱⁱⁱ	0.96	2.56	3.412 (4)	148
C31—H31C⋯O14^iv	0.96	2.56	3.504 (4)	168

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) .

Acknowledgments

MBA is grateful to COFFA and SIP IPN for financial support. The authors thank Professor Hugo Jimenez, ENCB-IPN, for the generous allocation of diffractometer time.

supplementary crystallographic information

Comment

Sucrose is an abundant and low cost sugar mainly used as natural edulcorant (Robyt, 1998), and when substituted by chlorine at certain positions as the artificial edulcorant sucralose (Fairclough et al., 1995). Despite this important usefulness sucrose has not been exploited sufficiently as synton for preparing modified derivatives containing isosteric substituents which could eventually lead us to pharmaceutical active substances (El Sayed & El Nemr, 2005; Furneaux et al. 1993). As a part of a strategy directed toward the preparation of modified sucrose derivatives we have prepared the title compound, a protected sucrose derivative which contains a benzylidene group at the 4 and 6 position of the glucopyranoside moiety and is fully acetylated at the remaining hydroxyl positions. This intermediate will allow us to functionalize the hydroxyl position at the pyranoside ring after deprotection of the benzylidene protecting group under mild conditions.

The title compound (Fig.1), shows two ⁴C₁ chair conformations belonging to the pyranoside and the 1,3-dioxane rings with puckering parameters (Cremer & Pople, 1975) Q = 0.572 (2) Å, θ = 7.7 (2)°, φ = 304.4 (15)° and Q = 0.577 (2) Å, θ = 0.0 (2)°, φ = 46 (7)°; both values being in agreement with a chair conformation. Also the angular disposition for the endocyclic bond C1—O5—C5 of 111.83 (15)° is in agreement with ⁴C₁ conformations having the substituents positioned at equatorial positions. The phenyl group is oriented almost perpendicular to the 1,3-dioxane and the acetate groups attached to the pyranoside ring are in equatorial positions. The α-anomeric C1—O1 bond value of 1.412 (2)Å is more enlongated than the reference value of 1.385 (4)Å for O-glycosidic bonds (Brito-Arias et al., 2007). For the furanoside ring the torsion angle values are 2.2 (2)° for C15—C14—O11—C17 revealing these elements to be almost in the plane and -28.9 (2)° for C14—C15—C16—C17 indicating an envelop exo E for C16, in agreement with a syn-periplanar conformation (Evans & Boeyens, 1989).

The analysis of potential hydrogen bonds shows different intramolecular and intermolecular C—H···O contacts are present (Table 1). The molecular packing is shown in Fig. 2, and some of the intramolecular O···C(acetyl) contacts, in the range 3.488 to 2.865 Å, are indicated in Fig. 3.

Experimental

The title compound was prepared by following a two step sequence starting from D-sucrose, which was treated with benzaldehyde dimethylacetal in dimethylformamide, followed by peracetylation under acetic anhydride-pyridine conditions. After purification by column chromatography the title compound was obtained as a white crystalline solid. ¹H NMR data are available in the archived CIF.