Racemic 7-(phenylacetamido)-1-dethia-3-aza-1-carba-2-oxacephem 3 was synthesized and found to possess antibacterial activity against Staphylococcus aureus FDA 209P, Escherichia coli ATCC 39188, Pseudomonas aeruginosa 1101–75 and Klebsiella pneumoniae NCTC 418 as well as the β-lactamase producing organisms E. coli A9675 and P. aeruginosa 18S-H and the methicillin-resistant organism S. aureus 95. Formation of the carbacephem 3 originated from the Barton photochemical reaction in the conversion of 8 to 10. Intramolecular cyclization of syn-oximino β-lactam 10 afforded 7-azido-2-oxa-3-azacephem 11, which was reduced and acylated to 12. Enzymatic removal of the methyl group from 12 gave the target molecule 3.
对映混合物7-(苯乙酰胺基)-1-
硫杂-3-氮杂-1-碳杂-2-氧代头孢烯3被合成,并发现其具有抗菌活性,对抗
金黄色葡萄球菌FDA 209P、大肠杆菌A
TCC 39188、
铜绿假单胞菌1101-75和肺炎克雷伯菌NCTC 418,以及产生β-内酰胺酶的菌株大肠杆菌A9675和
铜绿假单胞菌18S-H,还有耐
甲氧西林的
金黄色葡萄球菌95。碳杂头孢烯3的形成源于Barton光
化学反应在8到10的转化过程中。顺式-
肟基β-内酰胺10的分子内环化生成了7-
叠氮-2-氧-3-氮杂头孢烯11,后者被还原并酰化成12。通过酶学方法从12中去除甲基,得到了目标分子3。