Synthesis and biological evaluation of sulfur isosters of the potent influenza virus sialidase inhibitors 4-amino-4-deoxy- and 4-deoxy-4-guanidino-Neu5Ac2en

Abstract

The synthesis of the thioisosters of 4-amino-4-deoxy-Neu5Ac2en (16) and 4-guanidino-Neu5Ac2en (17) has been achieved. These compounds have been found to be as bioactive as the corresponding oxygen alalogues. The preparation of the key intermediate, 7,8,9,-tri-O-acetyl-2,6-anhydro-3,4,5-trideoxy-2′-methyl-6-thio-(methyl D-glycero-D-talo-non-2-enonato)[5,4-d]oxazole 13, has been achieved from 2-acetamido-2-deoxy-5,6-O-isopropylidene-3-thio-α-β-D-mannofuranose 8 in four steps in 43% overall yield.