(2R,4R)-4-(2-Isobutyrylamino-6-oxo-1,6-dihydro-purin-9-yl)-pyrrolidine-1,2-dicarboxylic acid 2-benzhydryl ester 1-tert-butyl ester

(S)-N-(diphenylmethyloxycarbonyl)methyl-2-azetidinone

benzhydryl 2-((2S,3R)-2-chloro-3-(1,3-dioxoisoindolin-2-yl)-4-oxoazetidin-1-yl)-3-(chlorothio)-3-methylbutanoate

Isopropoxythiocarbonylsulfanyl-diphenyl-thioacetic acid O-isopropyl ester