Synthesis of monodeoxy analogues of the trisaccharide alpha-D-Glcp-(1-->3)-alpha-D-Manp-(1-->2)-alpha-D-ManpOMe recognised by Calreticulin/Calnexin

Carbohydr Res. 2006 Jul 24;341(10):1533-42. doi: 10.1016/j.carres.2006.03.015. Epub 2006 Apr 17.

Abstract

Six (3,4,4',6',3'' or 6'')-monodeoxy analogues of the title trisaccharide (1-6) have been prepared utilising monodeoxy monosaccharide precursors. The reducing end deoxy derivatives were synthesised by N-iodosuccinimide/silver trifluoromethanesulfonate (NIS/AgOTf)-promoted couplings of a common disaccharide thioglycoside donor 10 to suitably protected monodeoxy acceptors 9 and 12, affording trisaccharides, which after deprotection yielded target structures 1 and 2. The non-reducing end deoxy derivatives could similarly be produced by halide-assisted glycosylations of a common disaccharide acceptor 17 with monodeoxy glycosyl bromide donors (obtained from thioglycosides 18 and 20) to yield, after removal of protecting groups, target trisaccharides 3 and 4. The analogues with the deoxy function in the middle mannose residue, were obtained through orthogonal halide-assisted coupling of tetrabenzyl-glucopyranosyl bromide to monodeoxy thioglycoside acceptors to give thioglycoside disaccharides, which subsequently were used as donors in NIS/AgOTf-promoted couplings to a common 2-hydroxy-mannose acceptor 15 to afford trisaccharides; deprotection yielded the final target compounds 5 and 6.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calnexin / metabolism*
  • Calreticulin / metabolism*
  • Carbohydrate Sequence
  • Deoxy Sugars / chemical synthesis*
  • Molecular Sequence Data
  • Trisaccharides / chemical synthesis*

Substances

  • Calreticulin
  • Deoxy Sugars
  • Trisaccharides
  • Calnexin