4-[(2S,3S)-3-Ethyl-4-oxo-1-((R)-1-phenyl-propylcarbamoyl)-3-propyl-azetidin-2-yloxy]-benzoic acid tert-butyl ester

4-[(2S,3S)-3-Ethyl-4-oxo-1-((R)-1-phenyl-butylcarbamoyl)-3-propyl-azetidin-2-yloxy]-benzoic acid tert-butyl ester

(3S,4S)-4-<<4-<(1,1-dimethylethoxy)carbonyl>phenyl>oxy>-3-ethyl-3-<1-(2-propenyl)>azetidin-2-one

(3S,4S)-4-<<4-<(1,1-dimethylethoxy)carbonyl>phenyl>oxy>-3-ethyl-3-propylazetidin-2-one

(3S,4S)-4-<<4-<(1,1-dimethylethoxy)carbonyl>phenyl>oxy>-3-ethyl-3-(methoxymethyl)azetidin-2-one