A new approach toward the preparation of macrocyclic lactones is introduced. The method is based on the use of tin derivatives as covalent templates. The latter are capable of directing the condensation of acyclic diols and diacyl dihalides to provide macrocyclic tetralactones as the sole ring products. The usefulness of the method is demonstrated by the preparation of a series of symmetric (6-9) as well as mixed (10) lactones in high yields. The ...
