| 摘要 |
A process for preparing a 4-acetoxy-3-hydroxyethylazetidin-2-one derivative having the formula (II): <CHEM> wherein R<1> is a protective group for the hydroxyl group, which comprises reacting a ss-lactam compound having the formula (I): <CHEM> wherein R<1> is as defined above, and R<2>, R<3> and R<4> are a lower alkyl group having l to 6 carbon atoms, phenyl group or an aralkyl group, with acetic anhydride in an organic solvent in the presence of a low concentration of a substituted pyridine. According to the present invention, there can be obtained 4-acetoxy-3-hydroxyethylazetidin-2-one derivatives, which are useful intermediates for preparing carbapenem ss-lactam antibiotics. |
