Stereoselective Synthesis of α-C-Substituted 1,4-Dideoxy-1,4-imino-d-galactitols. Toward Original UDP-Galf Mimics via Cross-Metathesis
摘要:
Various alpha-C-substituted 1,4-dideoxy-1,4-imino-D-galactitols were prepared efficiently from 1-O-acetyl-2,3,5,6-tetra-O-benzyl-D-glucofuranose by a four-step sequence involving as the key step the highly syn-selective TMSOTf-catalyzed addition of silylated nucleophiles to a glycofuranosylamine. Cross-metathesis of the alpha-C-allylated iminogalactofuranose derivative with an original uridin-5'-yl vinylphosphonate led to novel UDP-galactofuranose mimics. Such compounds are of interest as potential inhibitors of the mycobacterial galactan biosynthesis pathway.