An N-protected-3-acetyl-2-azetidinone-4-carboxylic acid ester has the formula:
wherein R1 and R2 are protecting groups.
The compounds are prepared by reacting a Schiff base R2-N=CH-COOR, with diketene in the presence of an imidazole.
In a further step the acetyl group is reduced and the carboxyl protecting group is then removed; the resultant β-lactam compounds are useful as intermediates for the production of carbapenem or penem derivatives.
一种 N-保护-3-乙酰基-
2-氮杂环丁酮-4-
羧酸酯的分子式为
其中 R1 和 R2 为保护基团。
该化合物是通过希夫碱 R2-N=CH-COOR 与二酮在
咪唑存在下反应制备的。
在进一步的步骤中,乙酰基被还原,然后羧基保护基被去除;得到的 β-内酰胺化合物可用作生产碳青霉烯或青霉烯衍
生物的中间体。