[(2-疏基-乙基氨基)-亚甲基]-氨基甲酸4-硝基-苄酯

4-nitrobenzyl 1-tert-butyldimethylsilyl-4-oxo-2-azetidin-α-butynoate

1-[tert-butyl(dimethyl)silyl]-4-prop-2-ynylazetidin-2-one

(4-nitrophenyl)methyl 4-(4-oxoazetidin-2-yl)but-2-ynoate

(4-nitrophenyl)methyl N-(3-hydroxyphenyl)carbamate