Prephenic acid
Prephenic acid, commonly also known by its anionic form prephenate, is an intermediate in the biosynthesis of the aromatic amino acids phenylalanine and tyrosine, as well as of a large number of secondary metabolites of the shikimate pathway.
It is biosynthesized by a -sigmatropic Claisen rearrangement of chorismate.Stereochemistry
Prephenic acid is an example of achiral molecule which has two pseudoasymmetric atoms, the C1 and the C4 cyclohexadiene ring atoms. It has been shown that of the two possible diastereoisomers, the natural prephenic acid is one that has both substituents at higher priority on the two pseudoasymmetric carbons, i.e. the carboxyl and the hydroxyl groups, in the cis configuration, or according to the new IUPAC stereochemistry rules.
The other stereoisomer, i.e. trans or, better,, is called epiprephenic.
