The general protocol of Fmoc synthesis:
The first Fmoc amino acid is attached to an insoluble support resin via an acid labile linker. Deprotection of Fmoc, is accomplished by treatment of the amino acid with a base, usually piperidine. The second Fmoc amino acid is coupled utilizing a pre-activated species or in situ activation. After the desired peptide is synthesized, the resin bound peptide is deprotected and detached from the solid support via TFA cleavage.
Disulfide bond formation:
Usually a peptide containing disulfide bonds is first assembled in a linear form with Cys in its sequence. The disulfide bond is formed after synthesis via solution phase, oxidative reagents, such as oxygen (air).