Identification and stereochemistry of the product of 4-HPPD catalyzed oxidation of the ketoacid of methionine

4-Hydroxyphenylpyruvate dioxygenase catalyzes the conversion of 2-oxo-5-thiahexanoic acid 1, the ketoacid from methionine (Scheme 1) to an unequal mixture of 4-thiapentanoic acid-4-oxide enantiomers 2a.