1,2-二氢-2-氧代螺[4H-3,1-苯并恶嗪-4,4'-哌啶]-1'-羧酸叔丁酯

1-Boc-哌啶

6-溴-4-氧代螺[苯并二氢吡喃-2,4-哌啶]-1-羧酸叔丁酯

4-苯基哌啶

5-氯螺[吲哚啉-3,4-哌啶]-1-羧酸叔丁酯