Synthesis, crystal structure and Hirshfeld surface analysis of Fmoc-β-amino butyric acid and Fmoc carbamate

In the context of the development of synthetic routes that facilitate the incorporation of β-amino acids into peptide synthesis, the synthesis, crystal structure and Hirshfeld surface analysis are reported of fluorenyl­meth­oxy­carbonyl (Fmoc) protected β-amino butyric acid, namely, 3-{[(9H-fluoren-9-ylmeth­oxy)carbon­yl]amino}­butanoic acid, C19H19NO4. The importance of pH control in the reaction employing Fmoc-N3 is demonstrated with another β-amino acid analogue from which Fmoc carbamate was identified as the major product.