An important role played dianiones in the highly efficient macrocycle formation by an intramolecular alkyltion method: application to the synthesis of zearalenone
macrolides based on intramolecular alkylation of dianions, generated from phenylthiomethyl group and protected cyanohydrin, is reported. The use of dianions for the cyclization has several characteristics features; (1) Control of the conformation fo the side-chain, (2) Protection of the ester from a nucleophilic attack, (3) Acceleration of the intramolecular reaction without using high dilution conditions