Synthesis, and X-ray crystal and molecular structure of a novel macro-bicyclic ligand: crowned p-t-butyl-calix[4]arene

Abstract
Capping of p-t-butyl-calix[4]arene (1a) with pentaethylene glycol ditoluene-p-sulphonate and ButOK in benzene leads to the first member of a new class of macrobicyclic crown compounds (2), which possess two cavities (one hydrophilic and one lypophilic) and two additional, ionizable binding sites.