Glycosyl donors and accepters may be covalently linked to aspartic acid residues via OH-6 esters. Peptide elaboration allows glycosylation reactions to be performed between donors and accepters linked to this peptide template. These reactions display increased regio- and stereoselectivities, which are dependent on the nature of the peptide. Simple molecular modelling is used to rationalise the differing product distributions obtained by variation of the linking amino acid sequence. (C) 2000 Elsevier Science Ltd. All rights reserved.