(1R,3'R)-3'-phenylhexahydrospiro[cyclopentane-1,5'-oxazolo[3,2-a]pyridin]-2-one

[(5S,7S)-1-[1-Cyano-meth-(E)-ylidene]-6-((R)-2-hydroxy-1-phenyl-ethyl)-6-aza-spiro[4.5]dec-7-yl]-acetic acid ethyl ester