Fmoc-Arg(Pmc)-OH is one of the popular arginine derivatives used in Fmoc solid phase peptide synthesis. The Pmc protecting group on Fmoc-Arg(Pmc)-OH has approximately the same lability as tBu based protecting groups and can be removed with TFA at the same time the peptide is cleaved from Wang or Rink amide resin. The Pmc group is a little less acid labile than the similar Pbf group. In general, arginine sidechain protecting groups in order of increasing acid lability is Tos, Mts, Mtr, Pmc, Pbf.
