(2S,5S)-N-allyl-2-(tert-butyldimethylsilyl)oxy-5-phenyl-2-(phenylseleno)acetyl-1,3-oxazolidin-4-one

(2S,6R,7aS)-7a-(tert-butyldimethylsilyl)oxy-6-methyl-2-phenyltetrahydropyrrolo[2,1-b]oxazol-3-one

O-ethylS-(((S)-5-oxo-1-((S)-1-phenylethyl)pyrrolidin-3-yl)methyl) carbonodithioate