A facile synthesis of α-N-ribosyl-asparagine and α-N-ribosyl- glutamine building blocks

Abstract

Adenosine diphosphate ribosylation (ADP-ribosylation) is a widely occurring post-translational modification of proteins at nucleophilic side chain of amino acid residues. Elucidation of ADP-ribosylation events would benefit greatly from the availability of well-defined ADP-ribosylated peptides and analogues thereof. In this paper we present a novel approach to the chemical synthesis of ribosylated amino acid building blocks using traceless Staudinger ligation. We describe an efficient and stereoselective synthesis of α-N-ribosyl- asparagine (α-N-ribosyl-Asn) and α-N-ribosyl-glutamine (α-Nribosyl-Gln) building blocks starting from 5-tert-butyldiphenylsilyl- β-D-ribofuranosyl azide. The N-glycosyl aminoacids are produced in good yields as pure α-anomers, suitably protected for peptide synthesis. © 2013 by the authors; licensee MDPI, Basel, Switzerland.