How is Poly-L-leucine (CAS: 25322-63-8) typically synthesized?

Poly-L-leucine (CAS: 25322-63-8) is synthesized by polymerization of L-leucine monomers. Common methods include solid-phase peptide synthesis using Fmoc chemistry or liquid-phase synthesis with N-carboxyanhydride (NCN) methods. The polymerization is typically carried out in a solvent such as DMF or DMSO under mild conditions. The yield and selectivity of the polymerization can be controlled by the choice of coupling agent and reaction conditions.