| 摘要 |
<p>A novel intermediate for synthesizing 1 beta -alkyl-1-carbapenem, i.e., 4 beta -(1 beta -alkyl-2-carboxyprop-2-enyl)azetidin-2-one ( II ), is prepared stereoselectively by treating 4-(leaving group substituted)azetidin-2-one ( I ) with trans-2-(leaving group substituted)methyl-3-alkylacrylic acid ( III ) and a reducing metal. <CHEM> wherein, R<1> is hydrogen, alkyl, or substituted alkyl; R<2> is optionally substituted alkyl; R<3> is hydrogen or a carboxy-protecting group; and R<4> and R<5> each is a leaving group.</p> |
