L-Aspartic acid 4-tert-butyl ester (S)-(-)-2-(Boc-Amino)-1,4-butanediol Succinimido (S)-2-[(tert-butoxycarbonyl)amino]propionate Boc-beta-alanine Mono-tert-butyl succinate N-Boc-L-Homoserine Boc-Asp-OtBu L-Aspartic acid (S)-N-BOC-3-AMINO-4-HYDROXYBUTYRIC ACID (3-OXO-PROPYL)-CARBAMIC ACID TERT-BUTYL ESTER