Sodium; (2S,3S)-3-{2-(2-amino-thiazol-4-yl)-2-[(Z)-methoxycarbonylmethoxyimino]-acetylamino}-2-methoxycarbonyl-4-oxo-azetidine-1-sulfonate

Sodium; (2S,3S)-3-{2-(2-amino-thiazol-4-yl)-2-[(Z)-1-methoxycarbonyl-1-methyl-ethoxyimino]-acetylamino}-2-methoxycarbonyl-4-oxo-azetidine-1-sulfonate

Sodium; (2S,3S)-3-{2-[(Z)-benzyloxyimino]-2-[2-(2-chloro-acetylamino)-thiazol-4-yl]-acetylamino}-2-methoxycarbonyl-4-oxo-azetidine-1-sulfonate

Sodium; (2S,3S)-3-{2-[2-(2-chloro-acetylamino)-thiazol-4-yl]-2-[(Z)-methoxycarbonylmethoxyimino]-acetylamino}-2-methoxycarbonyl-4-oxo-azetidine-1-sulfonate

Sodium; (2S,3S)-3-{2-[2-(2-chloro-acetylamino)-thiazol-4-yl]-2-[(Z)-1-methoxycarbonyl-1-methyl-ethoxyimino]-acetylamino}-2-methoxycarbonyl-4-oxo-azetidine-1-sulfonate