Asymmetric Synthesis of (2S,3S)- and (2R,3S)-2,3-Diaminobutanoic Acids, Non-Protein Amino-Acid Diastereomers found in a number of Peptide Antibiotics

Abstract

(2S,3S)- and (2R,3S)-2,3-diaminobutanoic acids (DABA) are uncommon, naturally occurring amino acid diastereomers found as components of a number of peptide antibiotics. These 2,3-diamino acids have been synthesised by direct and indirect routes, with addition of a chiral lithium amide to tert-butyl crotonate as a key step.