2,3,5,6-Tetrahydro-(1H)-indolizin-7-one hydrochloride

7-oxo-1,2,3,5,6,7-hexahydro-indolizine-8-carboxylic acid ethyl ester

1-Diazo-4-(2-thioxo-pyrrolidin-1-yl)-butan-2-one

ethyl 3-(2-(2-ethoxy-2-oxoethylidene)pyrrolidin-1-yl)propanoate