Sugar γ‐Amino Acids as Building Blocks for the Synthesis of Cyclic Neoglycopeptides.

Abstract

AbstractAnomeric sugar γ‐amino acids efficiently obtained by nucleophilic addition of nitronate anion on sugar olefins are useful building blocks for the preparation of new cyclic glycopeptides. Cyclopeptides have interesting biological properties or find potential applications as templates for anchoring of a wide range of biomolecules or detection dyes. We report here the synthesis of two types of cyclic systems containing γ‐glyco amino acid and α‐amino acid units. A first example was prepared to demonstrate the feasibility of the cyclization of these original structures. To explore the feasibility with more functionalized structures, α‐amino acid and sugar amino‐acid moieties bearing additional functions were chosen as building blocks for the second macrocycle. Furthermore, we describe and explain some unexpected results obtained during deprotection of these new cyclic glycopeptides.