4.5.2 Imine Formation

Compounds that can generate enolates react with aromatic nitroso compounds to give imine which on hydrolysis affords carbonyl group. For example, 2,4-nitrotoluene can be converted into 2,4-dinitrobenzaldehyde by this process.

4.6 α-Amino Acids, Peptides and Proteins

Peptides and proteins are naturally occurring polymers in living systems. They are derived from α -amino acids linked together by amide bonds. The distinction between peptides and proteins is that the polymers with molecular weights less than 10000 are termed peptides and those with higher molecular weights are termed proteins.

The acid-catalyzed hydrolysis of peptides and proteins provides the constituent α -amino acids which are, except glycine, chiral having L-configuration. The syntheses of peptides followed to date have been based on the reverse of this process. Therefore α -amino acids are of significant importance.

4.6.1 The Synthesis of α -Amino Acids

The following are the some of the common methods used for the synthesis of α -amino acids.