A modular approach to potential synthetic receptors with large surfaces based on crown[n]cavitands

Crown[n]cavitands were synthesized by alkylation of tetrahydroxycavitands with polyethyleneglycol ditosylates. The bridging of two hydroxy groups at adjacent aromatic rings by a pentaethyleneglycol unit is favored over the bridging of two hydroxy groups at opposite aromatic rings. The presence of a sodium base enhances the formation of the 1,2-crown[n]cavitand and improves the yield. The combination of 1,2-crown[6]cavitands with calix[4]arenes or resorcin[4]arenes resulted in potential receptor molecules with large hydrophobic surfaces.