Preparation of Benzene, Furan, and Thiophene Analogs of Duocarmycin SA Employing a Newly-Devised Phenol-Forming Reaction.
作者:Hideaki MURATAKE、Aki HAYAKAWA、Mitsutaka NATSUME
DOI:10.1248/cpb.48.1558
日期:——
route toward duocarmycin SA. The problem encountered at the crucial phenol forming step to secure 17a, b from 16a, b under the conventionally used Kuwajima conditions was overcome by devising a more convenient method: simple heating of 16a-c in benzene in the presence of bis(triphenylphosphine)palladium(II) chloride (10 mol%), cesium carbonate (3 eq), and triphenylphosphine (0.3 eq) gave 17a-c in high
以消旋形式合成了五种杜卡霉素SA 9a-e的A环类似物,从而改变了我们向杜卡霉素SA的第二条合成路线。通过设计更方便的方法克服了在关键的苯酚形成步骤中从传统的Kuwajima条件下将16a,b中的17a,b固定下来的问题:在双(三苯基膦)钯存在下,简单地在苯中加热16a-c (II)氯化物(10摩尔%),碳酸铯(3当量)和三苯基膦(0.3当量)以高产率86-91%得到17a-c。几乎根据所报道的途径,容易将中间体17a-e引入A环类似物(+/-)-9a-e。