An efficient method for the formation of macrocyclic dilactones via cyclization of (wcarboxyalky1) diphenylsulfonium salts 3 containing an ester linkage under mild conditions is described. These sulfonium salta 3 were cyclized in the presence of cesium carbonate under high-dilution conditions to give 11-to 16-membered dilactones 4 in good yields. The cyclization of sulfonium salt 22 was successfully carried out for the synthesis of 11- ...
