1-ethyl-2-[(E)-2-butenoyl]-5-spirocyclopentane-pyrazolidin-3-one

(1R,2R,6S,8R)-3-((E)-But-2-enoyl)-2,9,9-trimethyl-5-oxa-3-aza-tricyclo[6.1.1.02,6]decan-4-one

(1S,4R)-2-(3-methyl-2-propenoyl)-4,7,7-trimethyl-2-azabicyclo[2.2.1]-5-hepten-3-one

N,S-di(crotonyl)-2-mercaptoethyl anthranilate

(E)-1-((3R,3aR,6aR)-2-Benzyl-4,4-dioxo-3-phenyl-hexahydro-1-oxa-4λ6-thia-2,5-diaza-pentalen-5-yl)-but-2-en-1-one