methyl (2-(4-((2S,3R)-1-(4-fluorophenyl)-3-((S)-3-(4-fluorophenyl)-3-hydroxypropyl)-4-oxoazetidin-2-yl)phenoxy)acetyl)glycyl-D-valinate

(R)-3-Methyl-2-[(Z)-(7S,8R,9S)-7,8,9-tris-benzyloxy-9-((R)-2,2-dimethyl-[1,3]dioxolan-4-yl)-non-5-enoylamino]-butyric acid tert-butyl ester

(R)-2-(4'-Cyano-biphenyl-4-sulfonylamino)-3-methyl-butyric acid

(2-(4-((2R,3R)-1-(4-fluorophenyl)-3-((2-(4-(methylthio)phenyl)-2-oxoethyl)thio)-4-oxoazetidin-2-yl)phenoxy)acetyl)glycyl-D-valine

tert-butyl (2-(4-((2R,3R)-1-(4-chlorophenyl)-3-((2-(4-chlorophenyl)-2-oxoethyl)thio)-4-oxoazetidin-2-yl)phenoxy)acetyl)glycyl-D-valinate