Novel ester linked glycosyl amino acids: convenient building blocks for the synthesis of glycopeptide libraries

The completely orthogonally protected aspartic acid derivative FmocAsp(OBn) O'Bu is readily synthesized on a large scale. Deprotection of the beta-carb oxylic acid allows coupling to various sugar derivatives via free hydroxyl groups to produce novel glycosyl amino acids. Subsequent deprotection of ei ther the alpha-acid or nitrogen is achieved cleanly to allow elaboration in to an oligopeptide, whilst selective deprotection of PMB protected sugar hy droxyls is also readily achievable. Such novel glycosyl amino acid building blocks may be useful for the combinatorial synthesis of novel glycopeptide libraries. (C) 1999 Elsevier Science Ltd. All rights reserved.