Rapid access to Asp/Glu sidechain hydrazides as thioester precursors for peptide cyclization and glycosylation

Abstract

Head-to-sidechain macrocylic peptides, and neoglycopeptides, were readily prepared by site-specific amidation of aspartic and glutamic acid sidechain hydrazides. Hydrazides, serving as latent thioesters, were introduced through regioselective opening of the corresponding N_α-Fmoc protected anhydride precursors.