methyl (1S,3R,4R)-3-acetoxy-4-((tert-butoxycarbonyl)amino)cyclopentane-1-carboxylate

methyl (1S,3R,4S)-3-((tert-butoxycarbonyl)amino)-4-((methylsulfonyl)oxy)cyclopentane-1-carboxylate

二碳酸二叔丁酯

4-[[(1,1-二甲基乙氧基)羰基]氨基]-2-环戊烯-1-羧酸甲酯

(3aR,5R,6R,6aR)-6-bromo-2-oxo-hexahydrocyclopentaoxazole-5-carboxylic acid methyl ester