Dedicated to the memory of Professor Nikolay K. Kochetkov (1915–2005)
Novel glycosyl donors with a triisopropylsilyl (TIPS) nonparticipating group at O-2
were introduced for use in 1,2-cis-fucosylation. Coupling of 2-O-TIPS-substituted thiofucosyl donors with N-trifluoroacetyl-β-d-glucosamine mono- and disaccharide derivatives was found to lead exclusively to α-linked
oligosaccharides. No remote participation in 2-O-TIPS thiofucosyl donors seems to be required to favor α-selective fucosylation.
Key words
glycosylation - stereoselectivity - protecting groups - neighboring-group effects
- substituent effects