Diastereoselective Radical cyclization and enantioselective Au-catalyzed cyclization will be discussed. Radical cyclization reactions of alkoxyacrylates were selectively performed to produce two tetrahydropyran rings that have cis-related substituents. Total synthesis of SCH 351448 was accomplished employing the ring-closing olefin metathesis reaction for the preparation of the 28-membered macrodiolide. Analogous SCH 351448 salts incorporating other mono- and divalent cations may be prepared. Under acidic conditions, SCH 351448 (Na+ salt) was the most stable complex, but SCH 351448 (Ca2+ salt) and (Na+ salt) appear to be physiologically important species. The asymmetric intramolecular hydroamination of allenes catalyzed by phosphinegold(I)-bis-p-nitrobenzoate complexes will bedescribed. This reaction is applicable to the enantioselective formation of vinyl pyrrolidines and piperidines in 70-99% ee. With these outstanding counterion effects on gold, we developed high enantioselectivities conferred by a chiral counterion in a metal-catalyzed reaction. Two different transformations catalyzed by cationic gold (I) complexes generated products in 90 to 99% ee with the use of chiral binaphtholderived phosphate anions. Furthermore, the chiral counterion can be combined additively with chiral ligands to enable an asymmetric transformation that cannot be achieved by either method alone.