(3S)-3-{[(tert-butoxy)carbonyl]amino}-4-hydroxybutanoic acid is a chiral organic compound featuring both a Boc-protected amino group and a carboxylic acid functional group. It serves as a versatile chiral building block in organic synthesis, particularly valued for its (S)-configuration at the 3-position. This compound is primarily utilized as a key intermediate in the synthesis of various pharmaceutical agents. Its structure makes it a crucial precursor for the preparation of β-amino alcohols and γ-amino acids, which are important scaffolds in drug discovery. A prominent application is its use in the synthesis of the antiepileptic drug Brivaracetam and other related compounds targeting the central nervous system. The presence of orthogonal protecting groups (Boc and free acid) allows for selective modifications, facilitating its incorporation into more complex molecular architectures. It is commercially available and commonly used in medicinal chemistry research for constructing chiral pharmacophores.