Dieckmann-type cyclization reactions of various dicarboxylic acid derivatives were readily promoted by employing Lewis acids such as AlCl3, MgBr2, MgCl2, and Sn(OSO2CF3)2 in the presence of Et3N or N-ethylpiperidine. The cyclization reactions of half thiol diesters under the AlCl3-Et3N conditions exhibited different chemoselectivity from the cyclization under the basic conditions.