(E)-2-((1S,3'R)-3'-phenylhexahydrospiro[cyclopentane-1,5'-oxazolo[3,2-a]pyridin]-2-ylidene)acetonitrile

(R)-2-((2R,6R)-8-Benzyl-2-pentyl-1,8-diaza-spiro[5.5]undec-1-yl)-2-phenyl-ethanol

(S)-2-{(5R,7S)-7-[2-(tert-Butyl-dimethyl-silanyloxy)-ethyl]-6-[(R)-2-(tert-butyl-dimethyl-silanyloxy)-1-phenyl-ethyl]-6-aza-spiro[4.5]dec-1-en-1-yl}-propionitrile

[(5S,7S)-7-[2-(tert-Butyl-dimethyl-silanyloxy)-ethyl]-6-[(R)-2-(tert-butyl-dimethyl-silanyloxy)-1-phenyl-ethyl]-6-aza-spiro[4.5]dec-(1E)-ylidene]-acetonitrile

{(5S,7S)-6-[(R)-2-(tert-Butyl-dimethyl-silanyloxy)-1-phenyl-ethyl]-1-[1-cyano-meth-(E)-ylidene]-6-aza-spiro[4.5]dec-7-yl}-acetic acid ethyl ester