CAS 5438-24-4 appears in our catalog under these names: 5,6-Dimethyl-3a,4,7,7a-tetrahydro-2-benzofuran-1,3-dione, 95%, 5,6-Dimethyl-3a,4,7,7a-tetrahydroisobenzofuran-1,3-dione, 95+%, 5,6-Dimethyl-3a,4,7,7a-tetrahydro-isobenzofuran-1,3-dione. Offered by: Combi-blocks, AmBeed, Fluorochem. Available pack sizes: 250mg, 5g, 1g.