Synthesis of hydroxylated indolizidines and diamino suberic acid derivatives: use of tartaric acid and other approaches.

Tartaric acid enantiomers are very versatile and useful chiral pool compounds. Part of this research project was devoted to the study of these molecules as starting materials for the synthesis of biologically active natural products and analogs such as iminosugars and bis-a-amino acids. Bis-a-amino acids are a class of structurally interesting compounds. Among them, diaminosuberic acid is an appealing stable mimic of cystine. Object of this work was to synthetize different derivatives of diamino suberic acid using various strategies, including the tartaric acid approach, in order to get new interesting polyfunctionalized small molecules and to assess a stereoselective synthetic approach to the challenging structure of the aglycone of ascaulitoxin. Iminosugars are another class highly studied compounds. Lentiginosine is a natural iminosugar whose synthesis can be achieved by 1,3-dipolar cycloaddition of an enantiopure dialkoxypyrroline N-oxide, in turn derived from tartaric acid. The highly versatility of cyclic nitrones as precursors of azaheterocycles motivated the labeling a dialkoxypyrroline N-oxide with deuterium and its application to the synthesis of 8a-d-lentiginosine. It was also interesting to modify the parent structure of DHA, to try to control the half-life of the system and then insert an amino group useful to couple in an easy way DHA with biologically active products including amino acids. The last two projects presented, in addition to the synthetic challenge, some kinetic studies that were carried out using different techniques.