Studies on amino sugars. I. Synthesis of 5-amino-5-deoxyuronic acid and 5-amino-5-deoxysaccharic acid derivatives from D-glucuronolactone.

2-Amino-5-nitro­benzoic acid

In the title compound, C(7)H(6)N(2)O(4), an intra-molecular N-H⋯O hydrogen bond generates an S(6) ring. In the crystal, inversion dimers linked by pairs of O-H⋯O hydrogen bonds generate R(2) (2)(8) loops. Inter-molecular N-H⋯O and C-H⋯O hydrogen bonds then link the dimers, generating R(3) (3)(16)R(2) (1)(6) motifs. The whole mol-ecule is essentially planar, with the greatest deviation from the ...

2-Amino-5-fluoro­benzoic acid

In the title compound, C7H6FNO2, the mol-ecule is almost planar (r.m.s. deviation for the non-H atoms = 0.015 Å) and an intra-molecular N-H⋯O hydrogen bond closes an S(6) ring. In the crystal, inversion dimers linked by pairs of O-H⋯O hydrogen bonds generate R2(2)(8) loops. Weak N-H⋯F hydrogen bonds, short F⋯F contacts [2.763 (2) Å] and aromatic π-π stacking inter-actions [centroid-centroid sep...

Aminoglycoside antibiotics: synthesis of 5''-amino-5''-deoxyneomycin and 5''-amino-5''-deoxyparomomycin.

Cyclobutane serine amino acid derivatives as 5-hydroxyproline precursors

The synthesis of the 5-hydroxyproline derivatives 3a and 3b using cyclobutane serine analogs 1 and 2 as starting materials is reported. This process occurs with moderate cis/trans selectivity. A mechanism for this reaction is also proposed. Cyclobutane serine analog 1 was tested in tandem Michael and Wittig-like reactions, providing some evidence of the mechanism proposed.

5-Amino-2,4,6-triiodo­isophthalic acid monohydrate

The title compound, C(8)H(4)I(3)NO(4)·H(2)O, shows an extensive hydrogen-bond network; in the crystal structure, mol-ecules are linked by O-H⋯O, N-H⋯O and O-H⋯N hydrogen bonds involving all possible donors and also the water mol-ecule.