A total synthesis of 1, 2-dehydro-1-carbacephalosporin 2 (R2=CH3) is described. The azido-azetidinone 8, prepared from the Schiff base 5, azidoacetyl chloride and triethylamine, was converted to the ylide 13 via 10. Conjugate addition of benzenethiol to 13 followed by an intramolecular Wittig reaction gave the 1-carbacephem derivatives 16, which were transformed to the sulfoxides 17. Treatment of 17 with triethylamine yielded the 1, 2-dehydro derivative 18. The carboxylic acid derivatives 19, and 23, prepared from 18, did not show antibacterial activity.
描述了 1, 2-脱氢-1-碳
头孢菌素 2 (R2=
CH3) 的全合成。由希夫碱 5、
叠氮乙酰氯和
三乙胺制备的
叠氮基氮杂
环丁酮 8,通过 10 转化为内鎓盐 13。
苯硫酚与 13 共轭加成,然后进行分子内 Wittig 反应,得到 1-碳头孢烯衍
生物 16,将其转化亚砜17。用
三乙胺处理17得到1,2-脱氢衍
生物18。由18制备的
羧酸衍
生物19和23没有表现出抗菌活性。