作者:Nicolas Pichon、Anne Harrison-Marchand、Loic Toupet、Jacques Maddaluno
DOI:10.1021/jo0521854
日期:2006.3.1
A new stereocontrolled synthetic pathway to 1,2,4-trioxygenated 1,3-dienes from pyruvic aldehyde dimethyl acetal (14a) is described. Reacting the cyclohexylamine-derived imine of this starting material with chloroalkyl ethers under basic conditions affords ketoacetals 18−20, which were then transformed into eight different enoxysilanes 12. A δ-elimination triggered by tert-butyllithium yields 1,2,4-trioxygenated
描述了一种新的立体控制的合成途径,该途径由丙酮醛二甲基乙缩醛(14a)生成1,2,4-三加氧的1,3-二烯。反应与氯烷基醚在碱性条件下,得到ketoacetals该起始材料的环己胺衍生的亚胺18 - 20,然后将其转化到八个不同的enoxysilanes 12。叔丁基锂触发的δ消除反应产生1,2,4-三氧化二烯13。立体选择性地增加了甲硅烷氧基的体积或缩醛部分引线的所述(1个Ë,3 é)或(1个Ž,3 é)的异构体13, 分别。在13(13c,13d,13 g)和N-甲基马来酰亚胺或丙烯酸甲酯和苯丙烯酸酯之间进行高压[4 + 2]环加成反应可得到预期的环加合物,且具有良好的立体和区域控制能力。