Abstract In view of the prominent role of the 1H-indol-3-yl side chain of tryptophan in peptides and proteins, it is important to have the appropriately protected homologs H-β 2 [BOND] HTrp [BOND] OH and H-β 3 [BOND] HTrp [BOND] OH (Fig.) available for incorporation in β-peptides. The β 2-HTrp building block is especially important, because β 2- amino acid residues cause β-peptide chains to fold to the unusual 12/10 helix or to a ...
