| 摘要 |
<p>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 beta -lactam compound having the formula (I): <CHEM> wherein R<1> is as difined above and R<2>, R<3> and R<4> are the same or different and each is a lower alkyl group having 1 to 4 carbon atoms or an aralkyl group, with acetic anhydride in the presence of a base and a catalyst selected from the group consisting of an organic strong acid, a mineral acid, a Lewis acid, a halogenated acyl compound having the formula (IV): R<8>-CO-X (IV) wherein R<8> is an alkyl group, an aralkyl group or phenyl group and X is a halogen atom, a halogenated sulfonyl compound having the formula (V): R<9>-SO2-X (V) wherein R<9> is an alkyl group, an aralkyl group or phenyl group and X is a halogen atom, and a compound having the formula (VI): (R<1><0>)4-n-Si(X')n (VI) wherein R<1><0> is a lower alkyl group having 1 to 6 carbon atoms or phenyl group, X' is a halogen atom or CF3SO2O group and n is an integer of 1 to 4. According to the present invention, there can be obtained 4-acetoxy-3-hydroxyethylazetidin-2-one derivatives, which are useful intermediates for preparing carbapenem beta -lactam antibiotics, in high yield.</p> |
