(b)The procedure just described can be adapted to the synthesis of other amino acids. The groupattached to the a-carbon atom is derived from the alkyl halide used to alkylate diethylmalonate. Benzyl bromide (or chloride or iodide) would be appropriate for the preparation ofphenylalanine.27.27Acid hydrolysis of the triester converts all its ester functions to free carboxyl groups and cleavesboth amide bonds.The hydrolysis product is a substituted derivative of malonic acid and undergoes decarboxylationon being heated. The product of this decarboxylation is aspartic acid (in its protonated form underconditions of acid hydrolysis).Aspartic acid is chiral, but is formed as a racemic mixture, so the product of this reaction is notoptically active. The starting triester is achiral and cannot give an optically active product when itreacts with optically inactive reagents.27.28The amino acids leucine, phenylalanine, and serine each have one stereogenic center.
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This note was uploaded on 10/03/2011 for the course CHM 2210 taught by Professor Reynolds during the Fall '01 term at University of Florida.