Cephalosporin Lactone Impurity

Chemical Name: (5aR,6R)-6-amino-5a,6-dihydroazeto[2,1-b]furo[3,4-d][1,3]thiazine-1,7(3H,4H)-dione ; (5aR,6R)-6-Amino-5a,6-dihydro-3H,7H-Azeto[2,1-b]furo[3,4-d][1,3]thiazine-1,7(4H)-dione ; (5aR-trans)-6-amino-5a,6-dihydro-3H,7H-Azeto[2,1-b]furo[3,4-d][1,3]thiazine-1,7(4H)-dione

common.synonym: Desacetyl-7-ACA Lactone

Smile: O=C1OCC2=C1N3C([C@@](N)([H])C3=O)([H])SC2