M. Gobbo, L. Biondi, F. Filira
1988
Citations
0
Influential Citations
6
Citations
Journal
Tetrahedron
Abstract
Abstract The synthesis of the protected glycopeptide Z-Thr(tBu)-Ala-Thr-[α-D-Gal(Bzl) 4 ]-Thr(tBu)-NHNH-Boc was performed in solution by a stepwise coupling strategy. Fmoc-Thr[(α+β)-D- Gal(Bzl) 4 ]-0Su, obtained from the reducing sugar and the protected amino acid by the trifluoromethanesulfonic anhydride procedure, was reacted with H-Thr(tBu)-NHNH-Boc. The two diastereoisomers of the resulting glycosylated dipeptide derivative were purified and separated by column chromatography. The anomeric configuration of the 0-glycosidic linkage was assigned by 1 H-NMR-spectroscopy. The α-anomeric glycodipeptide, obtained in a larger amount, was selectively deblocked at the amino function and acylated with Z-Thr(tBu)-Ala-OH in the presence of either IIDQ or EEDQ, to afford the desired protected glycotetrapeptide.