(3aR,10aS,10bR)-octahydro-2H-furo[3,2-c]pyrrolo[1,2-a]azepine-2,8(1H)-dione

(-)-methyl (2S,3S,4R)-1-(tert-butoxycarbonyl)-2-{[(tert-butyldiphenylsilyl)-oxy]methyl}-4-isopropenylpyrrolidine-3-acetate

(R)-3-((S)-1-But-3-enyl-5-oxo-pyrrolidin-2-yl)-pent-4-enoic acid methyl ester

(S)-1-But-3-enyl-5-(tert-butyl-dimethyl-silanyloxymethyl)-pyrrolidin-2-one