| abstract |
4-Fluoroazetidinones of formula 1 <CHEM> wherein R is a carboxy-substituted or esterified carboxy-substituted butenyl group represented by the formulas <CHEM> and R1 is amino, amido, imido or imidazolidino or a pharmaceutically-acceptable salt thereof obtained from penicillin are useful intermediates in the preparation of beta -lactam antibiotics. 4-Fluoroazetidinones of formula 1 wherein R1 as described above other than amino, benzyloxycarbonylamino, p-nitrobenzyloxycarbonylamino, t-butyloxycarbonylamino, 2,2,2-trichloroethoxycarbonylamino, or p-methoxybenzyloxycarbonylamino; and R is a carboxy-substituted butenyl represented by the formula <CHEM> have antibacterial activity. |