3-hydroxymethyl-8-oxo-7-[(2-thienylacetyl)amino]-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid, DES-ACETYL CEPHALOTHIN, (6R-trans)-3-(hydroxymethyl)-8-oxo-7-(2-thienylacetamido)-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid, (6R)-3-hydroxymethyl-8-oxo-7t-(2-thiophen-2-yl-acetylamino)-(6rH)-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid, deacetylcephalothin, (6R,7R)-3-hydroxymethyl-8-oxo-7-(2-thiophen-2-yl-acetylamino)-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid, desacetylcephalotin