{(3aR,5S,6R,6aR)-5-[(R)-1,2-Di-hydroxy-eth-yl]-2,2-di-methyl-tetra-hydro-furo[2,3-d][1,3]dioxol-6-yl}methyl methane-sulfonate.

In the title compound, C11H20O8S, the furan-ose ring has a pseudorotation phase angle equal to 31.3° and assumes a (3) T 4 conformation, with deviations of 0.297 (4) and -0.152 (4) Šfor the corresponding C atoms. The dioxolane ring adopts an envelope conformation. One of the O atoms is at the flap and deviates from the least-squares plane formed by the other four ring atoms by 0.405 (2) Å. The dihedral angle between the planar fragments of the rings is 63.53 (8)°. In the crystal, mol-ecules are associated into sheets perpendiculer to the b axis by means of O-H⋯O hydrogen bonds. A few weak C-H⋯O inter-actions are also observed.

Synthesis and X-ray studies of novel 3-C-nitromethyl-hexofuranoses.

A practical method for the synthesis of three novel 3-C-nitromethyl-hexofuranoses is reported. The Henry reaction on a 1,2:5,6-di-O-isopropylidene-α-d-gulofuranose-derived ketone provided a 3-C-branched gulo-isomer as the sole reaction product. The dehydration-rehydration of the latter yielded an isopropylidene-protected 3-C-nitromethyl-galactofuranose. The reaction sequence can be also used for the synthesis of a 3-deoxy-3-C-nitromethyl-hexofuranose derivative with a gulo-configuration. Two of the newly obtained carbohydrate derivatives were characterized by X-ray crystallography.