(3R,4S)-4-(cyclohexylmethyl)-1-(4-methoxyphenyl)-3-((triisopropylsilyl)oxy)azetidin-2-one

(3R,4S)-1-(4-Methoxyphenyl)-3-hydroxy-4-(cyclohexylmethyl)-azetidin-2-one

(+)-(2S)-[(2R,3R)-3-benzyloxy-1-(4-methoxyphenyl)-4-oxoazetidin-2-yl][tert-butyl(dimethyl)silyloxy]acetonitrile

(+)-(2S,3R,4R)-4-benzyloxy-2-[tert-butyl(dimethyl)silyloxy]-5-hydroxy-3-[(4-methoxyphenyl)amino]pentanenitrile

tert-butyl (-)-(1R,2R)-2-benzyloxy-1-[(S)-[tert-butyl(dimethyl)silyloxy](cyano)methyl]-3-hydroxypropylcarbamate