2-[2-(2,2-Dimethyl-4,6-dioxo-1,3-dioxan-5-yl)-2-oxoethyl]-1H-Isoindole-1,3(2H)-dione is an intermediate in the synthesis of 5-Aminolevulinic Acid-3-13C Hydrochloride which is a naturally occurring amino acid; precursor of tetrapyrroles in the biosynthesis of chlorophyll and heme. Antineoplastic (photosensitizer).