91Ó°ÊÓ

The synthesis of a peptide is done by protecting the amino group of one amino acid with Boc or Fmoc group and protecting the carboxyl group of another amino acid as an ester.

After this, it is treated with DCC and then, removal of both protecting groups is done.

In this reaction, protection of Gly is done as a Boc derivative, and protection of carboxy group in Ala as an ester is done. A and B products then form an amide bond with DCC. After this, it reacts with HBr and ${\mathrm{CH}}_3\mathrm{COOH}$to form Gly-Ala.

In this reaction, protection of Ile is done as a Boc derivative, and protection of carboxy group in Ala as an ester is done. A and B products then form an amide bond when treated with DCC. After this, it undergoes elimination using ${\mathrm{H}}_2$and Pd catalyst to form C.

The protection of the carboxyl group in Phe as an ester is done. Now, this ester is treated with C and DCC. The compound formed further reacts with HBr and ${\mathrm{CH}}_3\mathrm{COOH}$forms Ile-Ala-Phe.