Synthesis of cholic acid-based molecular receptors: head-to-head cholaphanes

A novel synthetic strategy for the synthesis of head-to-head cholaphanes (II) using spacers, ethylenediamine or m-xylylenediamine as X and terephthalate as Y, has been reported. The synthesis constitutes the incorporation of different bile acids, viz. cholic and deoxycholic acids, thereby manipulating the number of hydroxy groups inside the cavity of cholaphanes.

The final cyclization step involving Cs salt methodology leads to the synthesis of cholaphanes 7a–c and 10a,b in high yields.