SOLID-PHASE SYNTHESIS OF A DIKETOPIPERAZINE CATALYST CONTAINING THE UNNATURAL AMINO-ACID (S)-NORARGININE

A cyclic dipeptide containing the unnatural amino acid (S)-norarginine , recently shown to display useful catalytic activity, has been synthe sized in good yield and high chemical purity using a solid phase proto col. All reactions in the sequence, including a Hofmann rearrangement and cyclization to diketopiperazine, were performed on the Merrifield polystyrene resin and proceed in high yield. In addition to its improv ed yield, this new synthesis offers easy access to derivatives and a p otential to employ combinatorial strategies to the search for novel ca talytic cyclic dipeptides. Copyright (C) 1996 Elsevier Science Ltd