[15] Convergent solid-phase peptide synthesis

This chapter discusses solid-phase synthesis and coupling of protected peptides. There are two main strategies for the chemical synthesis of peptides: (1) chain elongation in linear synthesis is carried out by repetitive Nαamino group deprotection and protected amino acid coupling steps, (2) convergent synthesis involves the synthesis and coupling of protected peptide segments. Both strategies can be carried out in solution or on a solid support, although solution and solid-phase methodologies can coexist in convergent synthesis. Protected peptide segments can be elaborated on solid supports and coupled in solution or vice versa. Convergent solid-phase peptide synthesis (CSPPS) involves (1) solidphase synthesis of protected peptides (these must retain the protecting groups of the Nα-amino and the side-chain functions after cleavage from the resin), (2) purification and characterization of the protected peptides, and (3) their solid-phase coupling.