Synthesis of two epimers of pseudopaline

Opines are a known group of compounds characterized by an elevated polarity. Recently, two new members of this class, staphylopine and pseudopaline, have been identified inStaphylococcus aureusandPseudomonas aeruginosa, respectively. These molecules are metal chelators that contribute to the growth of bacteria in particularly metal-poor environment. Different evidences suggest that these molecules might have an important role in the development of pulmonary infections in humans. Considering the impact ofP. aeruginosainfections in cystic fibrosis patients (prevalence up to 70 %), pseudopaline has risen interest as potential source of new therapeutic intervention. We present herein a straightforward synthetic approach for the synthesis of the two epimers of pseudopaline. Starting from a chiral building block, we attribute the absolute configuration to the two obtained diasteroisomers.