Undesired removal of the Fmoc group by the free ε-amino function of a lysine residue

✍ Scribed by Josep Farrera-Sinfreu; Miriam Royo; Fernando Albericio

• Book ID: 104251915
• Publisher: Elsevier Science
• Year: 2002
• Tongue: French
• Weight: 125 KB
• Volume: 43
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(02)01605-2

✦ Synopsis

In solid-phase peptide synthesis, a side-reaction consisting of the premature and undesired removal of the Fmoc group has been detected. This can be caused by a primary amine of sufficient basicity, such as the o-amino of the Lys, present in the peptide resin. This side-reaction, which is not promoted by either the b-amino side-chain of the Dapa residue or the a-amino group, can be prevented by a coupling/neutralization protocol in the case of Mtt protection or by a tandem deprotection-coupling reaction in the case of Alloc protection. The same kind of side-reaction has been detected when amino side-chain functions of Orn or Daba are free in the peptide resin.