tert-butyl (2S,5R,6Z)-3,3-dimethyl-6-[(4-nitrophenyl)methylidene]-4,4,7-trioxo-4lambda6-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate 在
三氟乙酸 作用下,
以70%的产率得到(2S,5R,6Z)-3,3-dimethyl-6-[(4-nitrophenyl)methylidene]-4,4,7-trioxo-4lambda6-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid