Question

Besides asymmetric hydrogenation (Section 29.4), several other methods are now available for the synthesis of optically active amino acids. How might a reaction like the Strecker synthesis be adapted to the preparation of chiral amino acids?

Short answer

Asymmetric hydrogenation constitutes a reaction that incorporates hydrogen atoms to a target molecule comprising three-dimensional selectivity. This selectivity arises from the reagents or catalysts.

Step-by-step solution

Asymmetric hydrogenation

Asymmetric hydrogenation constitutes a reaction that incorporates hydrogen atoms to a target molecule comprising three-dimensional selectivity. This selectivity arises from the reagents or catalysts.

Synthesis of amino acids

Amino acids can be generated using several ways, and one among them is the Strecker synthesis. Aldehydes are transformed into amino acids in this synthesis. The aldehyde combines with ammonia using a reagent like potassium cyanide.

An $\mathit{\alpha }$-amino acid is generated by condensation reaction. This gets subjected to hydrolysis to generate amino acid.

Preparation of chiral amino acids by Strecker synthesis

The chiral amine like R^*NH₂ or other chiral nitrogen-containing compound can create a chiral imine. This will favor the generation of one of the amino nitriles in Strecker synthesis.

The hydrolysis of the CN group and the removal of R*would then lead to the formation of the resulting amino acid.