The o-nitrobenzeneselenenamides were oxidized with active manganese dioxide to give the irnines, which were converted to the 7α-methoxycephalosporins 3 by the reaction with lithium methoxide. The selenenamides 3 were acylated with phenoxyacetyl chloride to afford the desired cephamycin derivatives 4 via tertiary amide 5, which was not isolable. This methoxylation reaction was also carried out in penicillin
邻
硝基苯硒酰胺用活性
二氧化锰氧化得到亚
氨酸,后者通过与
甲醇锂反应转化为 7α-甲氧基
头孢菌素 3。
硒酰胺 3 用苯
氧基乙酰氯酰化,通过叔酰胺 5 得到所需的头霉素衍
生物 4,其不可分离。该甲氧基化反应也在
青霉素系列中进行,得到所需的 6α-甲氧基
青霉素 8,尽管开环化合物 9 是主要产物。讨论了次磺酰胺和
硒酰胺在酰化反应中的区别。