An azetidinone derivative having the general formula (I): ##STR1## wherein R.sup.1 and R.sup.2 are hydrogen atom or a protective group and R.sup.3 is an alkyl group or hydrogen atom, a process for preparing the same, and a process for preparing an azetidinone derivative having the general formula (II): ##STR2## wherein R.sup.1, R.sup.2 and R.sup.3 are as above. The azetidinone derivative (I) of the present invention can be converted into an important intermediate of 1.beta.-methylcarbapenem antibiotics of a selective reduction of the double bond.
具有一般式(I)的氮杂环
丙酮衍
生物:##STR1##
其中R.sup.1和R.sup.2是氢原子或保护基,R.sup.3是烷基或氢原子,制备该衍
生物的方法,以及制备一般式(II)的氮杂环
丙酮衍
生物的方法:##STR2##
其中R.sup.1,R.sup.2和R.sup.3如上所述。本发明的氮杂环
丙酮衍
生物(I)可转化为1-β-甲基碳青霉烯类抗生素的重要中间体,通过选择性还原双键。