M. Bengtsson et al., CONVERGENT SYNTHESIS OF NEOGLYCOPEPTIDES BY COUPLING OF 2-BROMOETHYL GLYCOSIDES TO CYSTEINE AND HOMOCYSTEINE RESIDUES IN T-CELL STIMULATINGPEPTIDES, Glycoconjugate journal, 15(3), 1998, pp. 223-231
The 2-bromoethyl beta-glycosides of the disaccharide galabiose [Gal(al
pha 1-4) Gal] and the trisaccharides globotriose [Gal(alpha 1-4)Gal(be
ta 1-4)Glc] and 3'-sialyllactose [Neu5Ac(alpha 2-3)Gal(beta 1-4)Glc] h
ave been prepared by improved routes. The 2-bromoethyl glycosides were
then used in cesium carbonate promoted alkylations of the sulfhydryl
groups of cysteine and homocysteine residues in T cell stimulating pep
tides. This convergent and general approach was used to prepare 16 neo
glycopeptides which were obtained in 52-95% yields after purification
by HPLC. H-1 NMR spectroscopy revealed that beta-elimination and epime
rization of neoglycopeptide stereocentres did not occur during the syn
thesis.