Scalable Synthesis of 18-Crown-6 Based Lariat Ethers and Their Evaluation as Catalysts in Ester Hydolyosis

The syntheses of various Lariat crown ethers including several not previously reported and their efficient purification are presented. The synthesis route brings together reactions from a variety of previous works leading to a robust and generalized approach to these C-pivot lariats. The main steps are condensation of functionalized diols with penta-ethylene glycol ditosylate in the presence of potassium as a templating cation. Purification of the final products was achieved without chromatography by forming crown ether complexes with potassium nitrate followed by their precipitation. The catalytic activity of these lariat ethers in the hydrolysis of carboxylic esters was explored.