Highly Stereoselective .alpha.-Sialylation. Synthesis of GM3-Saccharide and a Bis-Sialic Acid Unit
作者:Teddy Ercegovic、Goeran Magnusson
DOI:10.1021/jo00116a022
日期:1995.6
The novel sialyl donor methyl [ethyl 5-acetamido-4,7,8,9-tetra-O-acetyl-2-thio-3-(phenylthic)-2,3,5- trideoxy-D-erythro -alpha-L-gluco-2-nonulopyranosid]onate (6) was synthesized in six steps from N-acetylneuraminic acid in an overall yield of 47%. Donor 6 was shown to be superior to conventional sialyl donors in that the sialylation yields were higher, even with sterically hindered and unreactive sialyl accepters, and the alpha/beta-selectivity was virtually complete.