Synthetic receptors with preorganized cavities that complex prednisolone-21-acetate

Abstract
Receptors 3a–c composed of two upper rim 1,2-difunctionalized calix[4]arene fragments, oriented either endo or exo, and one bridging cavitand unit, complex prednisolone-21-acetate with association constants of 4.3–8.3 × 102 dm3 mol–1 in CDCl3.