Abstract
A selective amide cleavage of dipeptide derivatives has been used for the resolution of N-acetylated alpha,alpha-disubstituted amino acids 3, prepared via the route in Scheme 2. Condensation of the racemic amino acids with (S)-Phe-N(CH3)2 gave the diastereomeric dipeptides 10 and 10' (Scheme 3), which were separated by flash-chromatography. Selective cleavage of the peptide bond yielded the enantiomeric amino acid derivatives 3/3' and 11/11', respectively.