| 摘要 |
<p>PURPOSE: A method for preparing an alkenyl azetidinone intermediate for carbapenem is provided to easily synthesize effective 1β-methyl carbapenem compound with low price. CONSTITUTION: A method for preparing an alkenyl azetidinone intermediate for carbapenem comprises: a step of preparation with 4(R)-acetoxyazetidinone as a starting material; a step of performing crotylation under the presence of chiral ligand, transition metal, and Lewis acid; and a step of producing 4-(alk-2-enyl)-2-azetidinone of the chemical formula 1. The chiral ligand is selected from cinchonine, cinchonidin, quinine, quinidine, norephedrin, O-acetylquinine, and O-acetylquinidine. The transition metal is selected from zinc or indium. The Lewis acid is selected from AgCl, PdCl, AgOTf, InCl3, ZnBr2, and Sc(OTf)3.</p> |
