219488-95-6Relevant academic research and scientific papers
Iodine monochloride/silver trifluoromethanesulfonate (ICI/AgOTf) as a convenient promoter system for O-glycoside synthesis
Ercegovic, Teddy,Meijer, Andreas,Magnusson, Goeran,Ellervik, Ulf
, p. 913 - 915 (2007/10/03)
matrix presented The novel promoter system iodine monochloride/silver trifluoromethanesulfonate (ICI/AgOTf) was evaluated with various thioglycoside donors and saccharide acceptors, and O-glycosides were obtained in 46-82% yield. Several practical advanta
A high yielding chemical synthesis of sialyl Lewis x tetrasaccharide and Lewis x trisaccharide; examples of regio- and stereodifferentiated glycosylations
Ellervik, Ulf,Magnusson, Goeran
, p. 9314 - 9322 (2007/10/03)
Virtually complete regioselective galactosylation of the diol acceptor p-methoxyphenyl 6-O-benzyl-2-deoxy-2-tetrachlorophthalimido-β-D- glucopyranoside (8) with the donor phenyl 2,3,4-tri-O-acetyl-6-O-benzyl-1- thio-β-D-galactopyranoside (11) gave the lactosamine derivative 14, which was fucosylated with the donor 15 to give the Le(x) trisaccharide glycoside 2 after deprotection. Regioselective sialylation of the partially protected Le(x) trisaccharide triol 24 with the sialyl donor 25 gave, after deprotection, the SLe(x) tetrasaccharide glycoside 1. The overall yields of 2 and 1 from the monosaccharide starting materials 8, 11, 15, and 25 were 56% and 29%, respectively. In contrast to the virtually complete regio- and stereoselective galactosylation of 8, fucosylation with the benzyl-protected donor 15 gave the corresponding 1→3- and 1→4-linked disaccharides in a ratio of 3.6:1 (highly stereo- but not regioselective glycosylation), whereas fucosylation with acetyl-protected donor 18 gave a 2.2:1 β/α-mixture of 4- O-linked disaccharides (highly regio- but not stereoselective glycosylation).
