(1,1'-Biphenyl)-4-butanoic acid, 2',4'-difluoro-alpha-methyl-gamma-oxo-, calcium salt (2:1) 161692-92-8 Calcium 2',4'-difluoro-alpha-methyl-gamma-oxo-(1,1'-biphenyl)-4-butanoate (2:1) Calcium 4-(2',4'-difluorobiphenyl-4-yl)-2-methyl-4-oxobutanoate