Free Radical Macrocyclisation via Propiolate Esters.

Article abstract of DOI:10.1016/0040-4020(92)85015-7

Intramolecular free-radical addition to propiolate esters has provided a new and stereoselective route to 14-16 membered trans-α,β-unsaturated macrocyclic lactones from their corresponding ω-iodoalkyl-propiolate esters under triphenyltin hydride/AIBN mediated conditions.Attempts to synthesise analogous 10-13 membered lactones proved unsuccessful, resulting in acyclic products derived from direct reduction at the radical centre. Key words: Radical; macrocyclisation; propiolate ester; macrocyclic unsaturated lactone; high dilutionm