A process for preparing a 4-acetoxy-3-hydroxyethylazetidin-2-one derivative having the formula (II):
wherein R¹ is a protective group for the hydroxyl group, which comprises reacting a ß-lactam compound having the formula (I):
wherein R¹ is as defined above, and R², R³ and R⁴ 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.
一种制备具有式(II)的 4-乙酰氧基-3-羟乙基氮杂
环丁烷-2-酮衍
生物的工艺:
其中 R¹ 是羟基的保护基团,该工艺包括使具有式(I)的 ß-内酰胺化合物反应:
其中 R¹ 如上定义,R²、R³ 和 R⁴ 是具有 l-6 个碳原子的低级烷基、苯基或芳烷基。根据本发明,可以得到 4-乙酰氧基-3-羟乙基氮杂
环丁烷-2-酮衍
生物,它们是制备碳青霉烯ß-内酰胺类抗生素的有用中间体。