Samuel J. Danishefsky used a Diels -- Alder reaction to synthesize disodium prephenate in 1979 .
Disodium prephenate is a biosynthetic precursor of the amino acids phenylalanine and tyrosine .
Samuel J. Danishefsky used a Diels -- Alder reaction to synthesize disodium prephenate , a biosynthetic precursor of the amino acids phenylalanine and tyrosine , in 1979 .