tert-butyl 2-((6S,7S,7aS)-3-oxo-6-(prop-1-en-2-yl)tetrahydro-1H,3H-pyrrolo[1,2-c]oxazol-7-yl)acetate

tert-butyl 2-((6R,7S,7aS)-6-acetyl-3-oxohexahydropyrrolo[1,2-c]oxazol-7-yl)acetate

tert-butyl 2-((6R,7S,7aS)-6-(dimethoxymethyl)-3-oxohexahydropyrrolo[1,2-c]oxazol-7-yl)acetate

(1S,3aS,4S,6aS)-1-(Hydroxymethyl)-4-methyl-2-(toluene-4-sulfonyl)-hexahydrocyclopenta(c)pyrrol-5-one

2-((3S)-2-(iodomethyl)-2-methyl-5-oxotetrahydrofuran-3-yl)acetic acid