Fmoc-Asn-OH, or Fmoc-asparagine, is a vital component in peptide synthesis, featuring a 9-fluorenylmethoxycarbonyl (Fmoc) protecting group attached to the asparagine molecule. Widely utilized in both solid-phase and solution-phase peptide synthesis, this derivative selectively shields the amino group of asparagine, facilitating controlled peptide chain elongation. Fmoc-Asn-OH is recognized for its compatibility with various coupling reagents and solid supports, making it a cornerstone in the field of peptide chemistry.