2-N-Benzyl-2,6-dide­oxy-2,6-imino-3,4-O-isopropyl­idene-3-C-methyl-D-allono­nitrile

X-ray crystallography firmly established the relative stereochemistry of the title compound, C₁₇H₂₂N₂O₃. The absolute configuration was determined by use of 2-C-methyl-D-ribonolactone as the starting material. The compound exists as O—H...N hydrogen-bonded chains of mol­ecules running parallel to the a-axis.

N-Benzyl-3,5-dide­oxy-3,5-imino-1,2-O-isopropyl­idene-β-L-lyxofuran­ose

X-ray crystallography confirmed the formation, structure and relative stereochemistry of the title compound, C₁₅H₁₉NO₃, which contains a sterically congested four-membered azetidine ring system. The absolute configuration was determined by the use of L-arabinose as the starting material.

N-(2-Carb­oxy­eth­yl)-2,5-dide­oxy-2,5-imino-D-mannonic acid [(3R,4R,5R)-1-(2-carb­oxy­eth­yl)-3,4-dihy­droxy-5-hy­droxy­methyl-L-proline]

The absolute stereochemistry of the title compound, C₉H₁₅NO₇, was determined from the use of D-glucuronolactone as the starting material. The compound crystallizes as the zwitterion. The five-membered ring adopts an envelope conformation with the –CH₂OH-substituted C atom forming the flap. An intramolecular N—H...O hydrogen-bond occurs. In the crystal, the compound exists as a three-dimensional O—H...O intermolecular hydrogen-bonded network with each mol­ecule acting as a donor and acceptor for four hydrogen bonds.