Synthesis of chiral N, N'-disubstitue mono and dibenzo 18-crown-6-ether derivatives

Almost as soon as the synthetic macrocyclic compounds became known through the work of Pedersen, chemist realized that asymmetric derivatives of these molecules could serve as models for the study of chiral recognition in enzymatic and other processes. The first synthetic chiral molecule was synthesized by Wudl and Gaeta in 1 972. The study of enantiomeric recognition of amine and protonated amine compounds is of significance since these compounds are basic building blocks of biological molecules. In nature, transport of amino acids through cell membrane is highly specific process owing to the chiral recognition properties of natural carriers. When chiral centers are located on pendant arms, chiral crown ethers show enantioselective transport of Z-aminoacids, amino acids K+,Na+,Li+ salts and dipeptideK+ carboxylates through a bulky chloroform membrane