Chemical Name: 4-{6-(4-Fluorophenyl)-7,8-epoxy-6-hydroxy-8a-isopropyl-7-phenyl-8-(phenylcarbamoyl)hexahydro-2H-pyrrolo[2,1-b][1,3]oxazin-2-yl}-3-hydroxybutanoic Acid
Synonym: Atorvastatin Cyclic 6-Hydroxy Impurity; Atorvastatin Epoxy Pyrrolooxazin 6-Hydroxy Analog (USP); Atorvastatin FXA Impurity (US);