CONFORMATIONALLY RESTRICTED ARGININE ANALOGS

We report the practical synthesis and structural characterization of a set of conformationally constrained protected arginine analogues. These enantiomerically pure analogues have the general structure 1 and are prepared in seven to eight steps from the commercially available isomers of 4-hydroxyproline. These analogues vary in side chain length and in relative and absolute stereochemistry and are suitable for the direct introduction into peptides. The resulting peptide analogues should be useful as enzymatically stable replacements for bioactive peptides and as probes for understanding the conformational aspects of protein-peptide interactions.