Cefivitril

(6R)-7α-[[[[(Z)-2-Cyanoethenyl]thio]acetyl]amino]-3-[[(1-methyl-1H-tetrazol-5-yl)thio]methyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid