CAS No:69388-79-0||Chemical Formula:C14H21NO7S||Molecular Weight:347.38200||Exact Mass:347.10387 ||(2S,5R)-3,3-Dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic Acid (2,2-Dimethyl-1-oxopropoxy)methyl Ester 4,4-Dioxide; (Pivaloyloxy)methyl Penicillanate S,S-Dioxide