Synthesis of oligomers derived from amide-linked neuraminic acid analogues

N-Fluoren-9-ylmethoxycarbonyl-protected sugar amino acids derived from alpha-O-methoxy- and 2,3-dehydroneuraminic acids have been prepared. Incorporation of these monomer units into solid-phase synthesis led to the efficient synthesis of two series of oligomers varying from one to eight units in length. The (1-->5)-linked amides of 2,3-dehydroneuraminic acid were further subjected to hydrogenation giving a third series of oligomers with a beta-hydrido substituent at the anomeric carbon.