1ξ-oxo-6β-phthalimido-1λ4-penicillanic acid methyl ester

(S)-2,2-dimethyl-7-oxo-6-phthalimido-2,3,4,7-tetrahydro-[1,4]thiazepine-3-carboxylic acid methyl ester

(2R,3S)-1-(1-methoxycarbonyl-2-methylprop-1-enyl)-3-phthalimido-4-oxoazetidine-2-sulphinic acid

3-methyl-2-(5-phthalimido-6-oxo-6H-[1,3]thiazin-3-yl)-but-2-enoic acid methyl ester

(S)-2,2-dimethyl-7-oxo-6-phthalimido-2,3,4,7-tetrahydro-[1,4]thiazepine-3-carboxylic acid methoxymethyl ester