Scheme 1.

Synthetic strategy for the preparation of peptides MARylated on their Ser‐, Thr‐ or Cys‐residue. P.G.=protecting group for amino acid side chains: Trt for serine/threonine/histidine, Mtt for lysine, 2‐PhiPr for glutamic acid, bis‐Alloc for arginine.