| abstract |
When 7β-amino-6αH-3-acetoxymethyl-8-oxo-4-thia-1-azabicyclo [4.2.0] octo-2-en-2-carboxylic acid is acylated with 2-thienylacetic acid, phenoxyacetic acid, methylsulfonylacetic acid, α-formyloxyphenylacetic acid, trifluoromethylmercaptoacetic acid, 2,2,2-trifluoroethylsulfinylacetic acid, cyanoacetic acid, cyanomethylmercaptoacetic acid, cyanomethylsulfinylacetic acid, cyanomethylsulfonylacetic acid-2-thienyl acetic acid. |