Question

The compounds commonly known as “amino acids” are actually -aminocarboxylic acids (Section 21.0). What carbonyl compounds should be used to synthesize the two amino acids shown here?

Short answer

a.

Carbonyl compound required for amino acid (a)

b.

Carbonyl compound required for amino acid (b)

Step-by-step solution

Reductive amination

The reaction of a carbonyl compound with ammonia in the presence of a reducing agent is called reductive amination.

Mechanism of reductive amination

Reductive amination involves two steps: reaction of the amine with the carbonyl and catalytic hydrogenation of produced imine or enamine.

Predicting starting material for the given amino acids

In reductive amination, the carbonyl oxygen is replaced by an amino group. Therefore, the starting materials for a given product can be determined by breaking the C-N bond in the product and adding oxygen to the carbon atom.