Synonyms: 5-Thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylicacid, 7-amino-8-oxo-3-(1-propenyl)-, diphenylmethyl ester, [6R-[3(Z),6a,7b]]-; 5-Thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylicacid, 7-amino-8-oxo-3-(1Z)-1-propenyl-, diphenylmethyl ester, (6R,7R)- (9CI)