Synthesis of 6<i>R</i>(β)-tritylaminopenicillanic-3<i>R</i>(β)-alcohol, a versatile stereoisomer of natural β-lactams
作者:F. De Meester、J. M. Frère、J. L. Piette、P. Jacquemin、L. Grooters、G. Llabres、S. Defays
DOI:10.1002/jhet.5570290242
日期:1992.3
have isolated the 3R(β)-carbinolamide derivative 4a. The trityl substituent on N(6′) seems to be responsible for the inversion of configuration which occurs at C(3) during the acid hydrolysis of the isocyanate intermediate. An hydrogen bond is formed on the β-face of the bell-shaped bicyclic skeleton between the N(6′)-nitrogen lone pair and the C(3) hydroxyl group. On standing, the carbinolamide analog
为了合理化在C(3)处修饰的青霉素类似物的合成,我们分离了3 R(β)-甲醇酰胺衍生物4a。N(6')上的三苯甲基取代基似乎负责异氰酸酯中间体酸水解过程中C(3)处构型的反转。在N(6')-氮孤对与C(3)羟基之间的钟形双环骨架的β面上形成氢键。静置时,羧酰胺类似物缓慢地异构化成其膨胀的双环异构体4b,但是通过用酸处理可以容易地回收起始原料。异构化过程中假定的中间体,即,开放的醛形式,不累积。C(3)处羟基的取代导致具有生物活性3 S(α)配置的各种化合物。这些可用于研究青霉素羧基在分子水平上与β-内酰胺酶相互作用的重要性。