| 摘要 |
<p>A multistep process is disclosed for preparing azetidinone intermediates used in the making penems and carbapenems wherein intermediates containing <IMAGE> R' is independently hydrogen or 1, 2 or 3 of lower alkyl or lower alkoxy, preferably hydrogen, wherein R'' is methyl, ethyl, a phenyl or alkyl, preferably ethyl, as a readily removable nitrogen protecting group are made.</p> |
