(3S,4S)-3-Hydroxy-5-[1-phenyl-meth-(Z)-ylidene]-3-propionyl-4-triethylsilanyloxy-pyrrolidin-2-one

(5S,9S)-8-(Z)-benzylidene-2-((2S,3R)-(Z)-3-but-1-enyloxiranyl)-3-methyl-9-triethylsiloxy-1-oxa-7-azaspiro[4.4]non-2-ene-4,6=-dione

(3S,4S)-3-{3-[(2R,3R)-((Z)-3-But-1-enyl)-oxiranyl]-3-hydroxy-2-methyl-propionyl}-3-hydroxy-5-[1-phenyl-meth-(Z)-ylidene]-4-triethylsilanyloxy-pyrrolidin-2-one