For our ongoing projects on the synthesis of aza-β 3 -peptides, we need to have ample access to the aza-β 3 -amino acid building blocks with proteinogenic side chains and N β -Fmoc protection. With the exceptions of aza-β 3 -Lys, aza-β 3 -Tyr, aza-β 3 -Arg only Fmoc-protected aza-β 3 -amino acids with nonfunctionalized and achiral side chains have been published. 10 We described here, in detail, the preparation of five new aza-β 3 -amino acid derivatives, ...
