2-Amino-2-deoxysugars are naturally occurring molecules which play a key role in a number of biological
and physiological events, such as molecular and immuno-recognition, as well as cell adhesion and differentiation.
However, the chemical synthesis of these amino sugars, and particularly of oligosaccharides incorporating them,
is still very challenging.
A simple one-pot azidochlorination for the preparation of nitrogen-containing Koenigs-Knorr glycosyl donors
proceeds upon reaction of protected glycals with sodium azide, ferric chloride, and hydrogen peroxide.
Different mono- and disaccharide galactals and glucals are converted in a highly α-selective manner to the
2-azido glycosyl chlorides. Starting from disaccharide galactals, building blocks for the synthesis of the T-antigen,
a tumor-associated carbohydrate antigen, are obtained in a straightforward manner. The simplicity of the reaction
conditions allows for an efficient and scalable α-selective synthesis of 2-azido substituted glycosyl chlorides.
C. Plattner, M. Höfener, N. Sewald, Org. Lett. 2011, 13, 545–547.