Synthesis of hexahomotrioxacalix[3]naphthalenes and a study of their alkali-metal cation binding properties

The first syntheses of the Cs-symmetrical and unsymmetrical hexahomotrioxac alix[3] naphthalenes 3 and 4, respectively, and the corresponding tert-buty l hexahomotrioxacalix[3] naphthalene 3a are reported. A convergent synthesi s of the linear hexahomotrimer precursors 19 and 19a is described, but the direct synthesis of 3 and 3a can also be achieved from the monomers 20 and 20a, respectively. A limited study of the binding properties of alkali-meta l cations by 3 or 3a using a picrate-CHCl3 extraction showed only weak abil ities to bind with the cations examined.