.beta.-Lactam compounds which are useful as intermediates for the production of carbapenem or penem derivatives and a process for producing the same. The process comprises reacting a Schiff base with diketene in the presence of an imidazole, reducing the acetyl group of the resulting N-protected-3-acetyl-2-azetidinone-4-carboxylic acid ester, and removing the protecting group for a carboxyl group from the resulting 3-(1-hydroxyethyl)-2-azetidinone-4-carboxylic acid derivative.
β-内酰胺化合物可用作头孢烯或
青霉素衍
生物的中间体,并提供了一种生产这些化合物的方法。该方法包括在
咪唑存在下将席夫碱与二酮反应,还原所得的N-保护-3-乙酰基-
2-氮杂环丁酮-4-
羧酸酯的乙酰基团,并从所得的3-(1-羟乙基)-
2-氮杂环丁酮-4-
羧酸衍
生物中去除保护基以得到羧基。