On the double bond isostere of the peptide bond: preparation of modified di- and tri-peptides incorporating proline and alanine analogues

Abstract

The preparation of some analogues of representative peptides that incorporate double bond isosteres of the sequences, Pro-Gly, Pro-Leu, Pro-Phe, Ala-Gly, and Ala-Ala, are described. The method of synthesis involves selective hydroboronation and oxidation of conjugated enynes, to generate βγ-unsaturated acids, followed by selective α-alkylation in order to introduce a second substituent into the ‘peptide’ backbone.