The synthesis of a 144-compound library of hydantoins and thiohydantoins spiro-fused to pyrrolidines is described. These compounds are synthesized from beta-aryl pyrrolidines, providing products with the 2-arylethyl amine moiety, a structural feature often encountered in compounds active in the central nervous system. All possible stereoisomers of the two-stereocenter products are synthesized. The 80-membered hydantoin sublibrary was obtained with yields ranging from 58 to 100% (87% average) and purities from 51 to 100% (87% average) and the 64-membered thiohydantoin sublibrary was obtained with yields ranging from 65 to 100% (89% average) and purities from 67 to 100% (93% average).