CAS 18635-49-9 appears in our catalog under these names: 4-tert-butyl 1-methyl (2S)-2-{[(tert-butoxy)carbonyl]amino}butanedioate, 98%, (S)-4-tert-Butyl 1-methyl 2-((tert-butoxycarbonyl)amino)succinate, 97%. Offered by: Combi-blocks, AmBeed. Available pack sizes: 5g, 1g.