8-溴-2,3,4,5-四氢-1H-吡啶并[4,3-b]吲哚

4-氧代哌啶酮盐酸盐

4-苄基-4-羟基哌啶

4-氨基-4-氰基-哌啶-1-羧酸叔丁酯

4-苯基-4-羟基哌啶