Asymmetric Synthesis of ω-Bromo-2(S)-methyl Acids as Precursors for Novel Arginine, Lysine, and Mercapto Residues

A series of ω‐bromo‐2(S)‐methyl acids has been synthesized as precursors of novel arginine (Arg), lysine (Lys), and mercapto analogues. These intermediates contain α‐methyl groups and are designed to mask the N‐terminal amine when incorporated in pharmaceutically relevant peptides.