Abstract: In this paper, we report that two series of novel optically active sulfur containing macrocyclic ligands have been synthesized by using L-cysteine as the source of chirality. The synthetic method is in the following: in the presence of NaHCO₃, L-cysteine reacts with dibromoalkane to form bridged bis-amino acids under a very mild condition, then, are transformed to the bis esters and cyclized with bis acid chlorides to give the targets 3a-3e. The other series are macrocyclic ligands with sulfur containing pendant. Firstly, L-cysteine reacts with PhCH₂Cl to give β-benzylthio-L-alanine, and then it is reduced to 2-amino-3-benzylthio-propanol by BH₃·THF. The amino alcohol reacts with bis-toluene-p-sulphonate of diethylene glycol to give the diamine 4f. The synthesis of 4g-4h is just like that of 4f.The cyclization of 4f-4h with 2,6-pyridinedicarbonyl dichloride gives the macrocyclic ligands 5f-5h. The structures proposed for these novel macrocycles are consistent with the data obtained from their ¹HNMR, MS and IRspectra and elemental analysis.

Key words: L-cysteine, Sulfur-containing chiral macrocyclic ligand, Synthesis, Characterization