Fmoc-D-Asn-OH, or Fmoc-D-asparagine, is a significant derivative in peptide synthesis, featuring a 9-fluorenylmethoxycarbonyl (Fmoc) protecting group attached to the D-enantiomer of asparagine. This compound plays a pivotal role in solid-phase and solution-phase peptide synthesis, selectively protecting the amino group of D-asparagine for controlled peptide chain elongation. Fmoc-D-Asn-OH is recognized for its compatibility with various coupling reagents and solid supports, contributing to its importance in the realm of peptide chemistry.