(2-Oxo-pyrrolidines)-acetic hydrazides
(2-Oxo-pyrrolidines)-acetic hydrazides
(4'-Biphenylyloxy and-thio-oxy)-3-hydroxy-3-pyrroline-2,5-diones
(Carboxy-oxo-pyrrolidino)phenylalkenamides and esters thereof as
(R,S)-1-(3-Hydroxy-4-methoxybenzoyl)-3-hydroxy-2-pyrrolidinone i