Iodolactonization

Abstract

The transformation of β,γ‐ or γ,δ‐unsaturated carboxylic acid derivatives into either a five‐or six‐membered lactone in the presence of a positive iodine source with concomitant group and face selectivity is commonly referred to as the iodolactonization. The study has been reported that this reaction can take place in a two‐phase system. It is considered that this reaction involves the initial addition of positive iodine on the unsaturated bond followed by the carboxylate anion displacement on the resulting iodonium ion. The reaction protocol has been modified via different positive iodine sources and different unsaturated acid derivatives, such as esters and amides. It has been used in an organic synthesis, particularly in the preparation of nucleosides and lactones with desired stereochemistry.