Structure of (E)-6,7,8,9-tetradeoxy-1,2:3,4-di-O-isopropylidene-7-nitro-α-D-galacto-non-6-eno-1,5-pyranose

The compound (C15H23NO7) crystallizes in the orthorhombic space group P2(1)2(1)2(1) (a = 12.330(1) Angstrom, b = 20.460(2) Angstrom, c = 6.753(1) Angstrom, Z = 4, D-c = 1.284, and D-m = 1.29 Mgm(-3) (mixture of bromobenzene and ethanol) T = 293 K. R(F) = 0.043 for 1325 observed hkl). Torsion angles confirm the E configuration along the C6-C7 double bond. The pyranose ring adopts a twist-boat conformation and the two dioxolane rings adopt different conformations, envelope and twist. The dihedral angles between the pyranose and dioxolane-rings least-squares planes are 83.9(2)degrees and 101.1(2)degrees. The molecule has an intramolecular hydrogen bond between the C and O atoms of the pyranose and the dioxolane rings. The crystal cohesion is stabilized by van der Waals forces.