Fmoc-(D₄)-Ala-OH was used by Bowman and Zaia in the SPPS of peptide tags for the stable isotopic labeling of carbohydrates which allowed their mass spectroscopic quantification. For ²H-NMR-studies on the influence of Pro on the folding of WALP transmembrane peptides, Koeppe’s group incorporated pairs of deuterated alanines by introducing Fmoc-(D₄)-Ala-OH (60-100%) at selected sequence positions.