Sulfoaminoglucitols: synthesis of 2-amino-2,3 (and 2,6)-dideoxy-d-glucitol-3 (and 6)-sulfonic acids and X-ray crystal structure of the monohydrate of the 6-sulfo derivative

2-Amino-2,3-dideoxy-d-glucitol-3-sulfonic acid (3) and 2-amino-2,6-dideoxy-d-glucitol-6-sulfonic acid (4) were prepared by reduction of 2-amino-2,3 (and 2,6)-dideoxy-d-glucopyranose-3 (and 6)-sulfonic acids with sodium borohydride. The crystal structure of 4 monohydrate (C6H15NO7S · H2O) is orthorhombic, space group P212121 with unit cell dimensions a = 8.289(2), b = 24.548(5), and c = 5.149(2) Å. A planar zig-zag conformation is observed in which N-2 and O-4 atoms are aligned 1,3-parallel, stabilized by an intramolecular hydrogen bond (N-H … O–4). The sulfo and the amino group form a zwitterion and two conformations are found for the ammonium group.