Nitroacetyl Group as a Peptide Synthon: Synthesis of Dipeptides with an α,α‐Bisallylglycine Residue at the N‐Terminus

Abstract

Abstract N ‐Nitroacetyl derivatives of L‐proline, L‐valine, and L‐phenylalanine esters were prepared in two steps under mild conditions ( Scheme 2 ). Regiospecific mono‐ and bis‐allylation of these nitroacetyl derivatives were accomplished in presence of a Pd(0) catalyst. The bis‐allyl derivatives 7–9 were obtained in 40–75% yield. The tertiary NO 2 group in these compounds could be transformed into an acetylamino group by Zn/AcOH/Ac 2 O. The final products 11–13 are dipeptides in which the N‐terminal glycine residue bears two α‐allyl substituents.