摘要:
A simultaneous stereoselective 2-O-deacetylation and 4-amination reaction of peracetylated Neu5Ac 1 has been established with cyclic secondary amines, such as 1-N-Boc-piperazine. Four C-2-symmetric and two asymmetric sialic acid dimers with (4 -> 4)-piperazine derivatives linked were synthesized. They may serve as precursors of unnatural polysialic acids. (c) 2008 Elsevier Ltd. All rights reserved.