Total Synthesis of Sequential Retro‐Peptide Oligomers

Abstract

AbstractThe total synthesis of sequential oligomers of retro‐peptides of the general formula Boc(‐gGly‐mAib)n‐OBn, starting from dimethylmalonic acid, has been carried out in good overall yield. The key step is the formation of the gGly unit >N−CH2−N<, which is easily obtained in a one‐pot/three‐step reaction from BnO‐mAib‐Gly‐OH and diphenylphosphoryl azide. The synthesis of the sequential oligomers of RCO(‐gAla‐mAib)n‐OR′ was also attempted, but the oligomerization step failed because the gAla moiety readily decomposes or racemizes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)