Galabiosyl donors; efficient synthesis from 1,2,3,4, 6-penta-O-acetyl-beta-D-galactopyranose
1Organic Chemistry 2, Center for Chemistry and Chemical Engineering, Lund University, Sweden.
Abstract:
1,2,3,4,6-Penta-O-acetyl-beta-D-galactopyranose was transformed into phenyl 2,3,4,6-tetra-O-benzyl-1-thio-beta-D-galactopyranoside (5) and 4-methoxyphenyl 2,3,6-tri-O-benzoyl-beta-D-galactopyranoside (8) in 73% (two steps) and 58% (three steps) yield, respectively. Glycosylation of the acceptor 8 with donor 5 using N-iodosuccinimide-trimethylsilyl trifluoromethanesulfonate as promoter furnished the galabioside 9 (8.8 g) in 95% yield. Further transformations provided in high yields anomerically-activated galabiosides (thioglycoside (1), trichloroacetimidate (2), and bromosugar (3)) suitable for use as glycosyl donors in syntheses of galabiose-containing oligosaccharides. Several of the compounds reported here are crystalline, which greatly simplified purifications.
Related Concept Videos
Oligosaccharide Assembly
Multiple sugar molecules that may or may...
Biosynthesis of Polysaccharides
Protein Glycosylation
Glycosylation occurs in...
Alkylation of β-Diester Enolates: Malonic Ester Synthesis


