CAS 1217977-71-3 appears in our catalog under these names: (S)-2-Amino-4-(tert-butoxy)-2-methyl-4-oxobutanoic acid, 97%, 97%, (S)-ALPHA-METHYLASPARTIC ACID-4-TERT-BUTYL ESTER, 95%. Offered by: Chemat, Fluorochem. Available pack sizes: 100mg, 250mg, 1g.