Synthesis and Properties of Substituted CBI Analogs of CC-1065 and the Duocarmycins Incorporating the 7-Methoxy-1,2,9,9a-tetrahydrocyclopropa[<i>c</i>]benz[<i>e</i>]indol-4-one (MCBI) Alkylation Subunit: Magnitude of Electronic Effects on the Functional Reactivity
作者:Dale L. Boger、Jeffrey A. McKie、Hui Cai、Barbara Cacciari、P. G. Baraldi
DOI:10.1021/jo952033g
日期:1996.1.1
radical-alkene cyclization (24 --> 25, 32 --> 33) for completion of the synthesis of the 1,2-dihydro-3H-benz[e]indole skeleton and final Ar-3' alkylation of 28 for introduction of the activated cyclopropane. Two approaches to the implementation of the key 5-exo-trig free radical cyclization are detailed with the former proceeding with closure of 24 to provide 25 in which the required product functionalization was
在以下文献中描述了7-甲氧基-1,2,9,9a-四氢环丙烷[c]苯并[e]吲哚-4-酮(MCBI)的合成,MCBI是带有对C4羰基的C7甲氧基的取代的CBI衍生物。努力确定对试剂的化学和功能反应性的潜在电子效应的大小。通过修饰的Stobbe缩合/ Friedel-Crafts酰化反应制备MCBI烷基化亚基的核心结构,以生成适当官能化的萘前体(15和20),然后进行5-exo-trig芳基自由基-烯烃环化(24-> 25、32-> 33)完成1,2-二氢-3H-苯并[e]吲哚骨架的合成,最后28的Ar-3'烷基化,以引入活化的环丙烷。详细介绍了实现关键的5-exo-trig自由基环化的两种方法,前者以24结束,以提供25,其中在环化之前引入了所需的产品功能化,而后者则用了环化产物的Tempo捕集器官能化的未反应的烯烃底物32提供33%。后一种简洁的方法以极好的总转化率(27-30%)以12-