Show the steps in the synthesis of the tetrapeptide Leu-Phe-Ala-Val.

Peptide synthesis involves the formation of peptide bonds between amino acids to create peptides. This process typically follows the stepwise addition of protected amino acids, where the carboxyl group of one amino acid reacts with the amino group of another, releasing water. Understanding the mechanisms of peptide bond formation is crucial for synthesizing specific sequences like tetrapeptides.

In peptide synthesis, protecting groups are used to prevent unwanted reactions at the functional groups of amino acids. For example, the amino group can be protected with a group like Fmoc or Boc, allowing for selective coupling of amino acids in a desired sequence. Mastery of protection and deprotection strategies is essential for successful synthesis.

Solid-phase peptide synthesis (SPPS) is a widely used method for synthesizing peptides, where the growing peptide chain is anchored to a solid resin. This technique allows for easy washing and purification of intermediates, facilitating the stepwise addition of amino acids. Understanding SPPS is vital for efficiently synthesizing complex peptides like Leu-Phe-Ala-Val.