2-propenyl (3S,5R,6R)-2,2-dimethyl-6-(phenylacetamido)-7-oxopenam-3-carboxylate

(6R)-3-methylene-8-oxo-7t-(2-phenyl-acetylamino)-(6rH)-5-thia-1-aza-bicyclo[4.2.0]octane-2ξ-carboxylic acid

(6R)-3-methyl-8-oxo-7t-(2-phenyl-acetylamino)-(6rH)-5-thia-1-aza-bicyclo[4.2.0]oct-3-ene-2ξ-carboxylic acid benzhydrylidene-methyl-hydrazide