Efficient Synthesis of 4-Amido-<i>N</i><sup>5</sup>-acetyl-4-deoxyneuraminic Acid and Its Application to the C-4 Modification of Sialic Acids
作者:Zheng-Xi Gao、Meng Wang、Shaozhong Wang、Zhu-Jun Yao
DOI:10.1021/ol901511x
日期:2009.8.20
A straightforward synthesis of 4-amido-N5-acetyl-4-deoxyneuraminic acid, a key precursor to various 4-amidoneuraminic acid analogues, has been achieved using a highly regioselective and diastereoselective [3 + 2]-cycloaddition of d-mannose-derived nitrone with methyl acrylate. Advantages of this newly developed synthesis include the use of economically available materials and reagents, the ease of
gave a mixture of 3,4:5,6-di- O -isopropylidene- aldehydo - d -glucose dibenzyl acetal (1) and 2,3:5,6-di- O -isopropylidene- aldehydo - d -glucose dibenzyl acetal in good yield. The conversion of 1 into 2-amino-2-deoxy- d -mannose derivatives was accomplished, stepwise, via the nucleophilic displacement reaction of the trifluoromethanesulfonic ester of 1 with sodium azide.