Sialic acid derivatives having active carbonyl group.

摘要

A sialic acid derivative having an active carbonyl group represented by the formula [I]: <CHEM> (wherein R<1> represents hydrogen or acetyl group; R<2> represents hydrogen, a metal or a lower alkyl group; R<3> represents hydrogen, hydroxyl group, or a residue removed hydrogen from an alcohol portion of an active ester; Ac represents acetyl group; and n is 1 to 20, respectively). This sialic acid derivative [I] can be utilized as a starting material for various complex having a sialic acid in the molecule since it has an active carbonyl group in the molecule so that it shows high reactivity.