Aims of the present work
- To envisage a new and high yielding synthetic procedure allowing
(1) as the only macrocyclic product, thus making easier the isolation
and purification.

- To investigate the complexation of receptors (2) and (3) mainly
towards ammonium and mono- alkylammonium salts.

- To design and synthesize a new polycyclic receptor (4) in which (1)
is used as a building block.
