2-Methyl-2-propanyl 2-(2,4-dimethoxybenzyl)-1-oxo-2,5-diazaspiro[ 3.4]octane-5-carboxylate

[1-(2,4-Dimethoxy-benzyl)-3-methyl-2-oxo-azetidin-3-yl]-carbamic acid tert-butyl ester

[1-(2,4-Dimethoxy-benzyl)-3-isopropyl-2-oxo-azetidin-3-yl]-carbamic acid tert-butyl ester

[1-(2,4-Dimethoxy-benzyl)-3-methyl-2-oxo-azetidin-3-yl]-carbamic acid benzyl ester

(S)-N-[(R)-1-(2,4-Dimethoxy-benzyl)-3-isobutyl-2-oxo-azetidin-3-yl]-3-methyl-2-{(S)-2-[2-(3-phenoxy-phenyl)-acetylamino]-3-phenyl-propionylamino}-butyramide