基于化学反应和CD光谱数据,讨论了5,6-顺式-卡巴培南抗生素在亚砜处的绝对构型。通过加氢,氧化和Z,E-异构化的结合,由C-19393 H 2合成了一些侧链的立体异构体。CD光谱研究表明,立体异构体在亚砜的棉花效应表明在260-275和280-300 nm区域有明显相反的迹象。进一步的CD光谱研究表明,这些棉花效应可能反映了两个发色团。对于前一个地区和后者。总之,已证明这些天然存在的5,6-顺式-卡巴培南抗生素具有R-在亚砜处的构型。
Naturally occurring carbapenemantibiotics having a double bond in the side chain, when refluxed in chloroform containing quarternary alkylammonium halides, were converted into Z isomers in high yields. The mechanism of this new equilibration involves intramolecular proton transfer from the carboxylic acid to the carbon alpha to the sulfur atom in the side chain as shown by deuterium-labeling experiments