Enantioselective Synthesis of Isotopically Labeled Homocitric Acid Lactone

A concise synthesis of homocitric acid lactone was developed to accommodate systematic placement of carbon isotopes (specifically C-13) for detailed studies of this cofactor. This new route uses a chiral allylic alcohol, available in multigram quantities from enzymatic resolution, as a starting material, which transposes asymmetry through an Ireland-Claisen rearrangement.