Thermodynamically-controlled cyclisation and interconversion of oligocholates: metal ion templated ‘living’ macrolactonisation

A series of ester-linked macrocyclic oligomers (dimer–pentamer) of cholates equipped with a variety of recognition and reporter elements has been prepared (a) by conventional irreversible chemistry, and (b) using methoxide-catalysed transesterification under reversible equilibrium conditions. Templating by metal ions under these equilibrium conditions is also demonstrated. These results demonstrate the feasibility of creating a dynamic combinatorial library of receptors.