Synthesis and cation complexation properties of new macrolides

The cis-2-alkyl-3-oxy-tetrahydropyran unit as a novel structure for the design and synthesis of a new type of ionophores with C2-symmetry is reported. The synthesis of seven different macrolides and a crown ether and their cation complexation properties were investigated. The X-ray crystal structure of some of the receptors provides valuable information on the preferred conformation of tetrahydropyrans in the solid state that can be related to the cation complexation properties in solution. The kinetic template effect has been proved to be a useful tool to improve the yield and selectivity in the synthesis of macrodiolide .