(2-Oxo-4-tritylsulfanyl-azetidin-1-yl)-(triphenyl-λ5-phosphanylidene)-acetic acid 4-nitro-benzyl ester

4-(2-Oxo-4-tritylsulfanyl-azetidin-1-yl)-but-2-ynal

Hydroxy-(2-oxo-4-tritylsulfanyl-azetidin-1-yl)-acetic acid 2-trimethylsilanyl-ethyl ester