The two isomers 6 and 9 of cis(4,4′-)-dicarbomethoxydibenzo-27-crown-9 with tri- and tetra-(ethyleneoxy) linkages transposed were synthesized regiospecifically in high yields (94 and 92%, respectively) by the Wang–Pederson–Wessels (WPW) protocol and were converted via the corresponding diols 7 and 10 to the corresponding pyridyl cryptands 3 and 4 by reaction with pyridine-2,6-dicarbonyl chloride. As
两种异构体6和9的顺式(4,4'-)- dicarbomethoxydibenzo-27冠9与三-和四- (亚乙基氧基)键被转置以高产率(分别为94和92%),由区域专一性合成Wang-Pederson-Wessels(WPW)协议,并通过与
吡啶2,6-二羰基
氯反应,通过相应的二醇7和10转化为相应的
吡啶基隐窝3和4。如从科里-鲍林-Koltun(CPK)的模型,用三(亚乙基氧基)臂穴状
配体预期对位到酯键,“短武装”
穴醚3与
百草枯相比,
百草枯确实显示出更高的结合常数(K a = 2.4×10 5 M –1);但是,效果只有两倍。它与
敌草快的结合减少了一个数量级(1.5×10 5 M –1),这是基于其狭窄腔体的预期。也正如所料,用四(亚乙基氧基)臂穴状
配体对位到酯键,“长臂”
穴醚4,具有降低与两个paraquats和
敌草快相对于基于30冠类似物结合; 在这些系统中,质谱也检测到了2:1 H