AN EFFICIENT METHOD FOR THE SYNTHESIS OF MACROCYCLIC LACTONE

Abstract
Long chain ω-hydroxycarboxylic acids were quantitatively converted to 6-phenyl-2-pyridyl esters by the treatment of the acids with 6-phenyl-2-pyridone and 2-chloro-1-methylpyridinium iodide in the presence of triethylamine. These esters were cyclized in refluxing methylene chloride by the promotion of p-toluenesulfonic acid to give macrocyclic lactones in high yields.